Location: MSHCP > VOLUME 2 > REPTILES
Belding's orange-throated whiptail (Cnemidophorus hyperythrus beldingi)
State: Species of Special Concern, and State Protected Species
Federal: None
The Belding's orange-throated whiptail population is widespread throughout the Plan Area. The orange-throated whiptail occurs in a wide variety of habitats but is more closely tied to coastal sage scrub and chaparral habitats with less than 90 percent vegetative cover. The species is common in most areas of the Plan Area within the central basin and foothills areas. No specific management regimes are needed to maintain adequate habitat for this species, although management of habitat for species such as the Stephens' kangaroo rat, San Bernardino kangaroo rat, and Los Angeles pocket mouse may benefit the orange-throated whiptail.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 226,313 acres of coastal sage scrub, desert scrub, chaparral, Riversidean alluvial fan sage scrub, and riparian scrub and woodlands within the Riverside lowlands, San Jacinto Foothills, and Santa Ana Mountains Bioregions below 1,040 meters. The majority of habitat conservation will occur in large core blocks throughout the Plan Area.
Include within the MSHCP Conservation Area at least nine Core Areas including Santa Rosa Plateau (8,360 acres), Lake Skinner-Diamond Valley Lake (29,070 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake (50,000 acres), and Anza Valley (4,290 acres) and numerous smaller Proposed and Existing Noncontiguous Habitat Blocks.
For purposes of this conservation analysis, potential habitat for the orange-throated whiptail includes coastal sage scrub, chaparral, desert scrub, Riversidean alluvial fan sage scrub, and riparian scrub and woodland below 1,040 meters within the Riverside Lowlands, San Jacinto Foothills, and the Santa Ana Mountains Bio-Regions. Although this species primarily occurs within sparsely vegetated portions of these habitat types, there is not sufficient information to determine percent vegetation cover throughout the Plan Area. Therefore, for this conservation analysis we assume that 50 percent of these habitat types in the specified Bioregions are potentially suitable for this species. Based on these criteria, the Plan Area supports approximately 383,966 acres of potential habitat for the orange-throated whiptail. Table 1 shows the conservation of potential habitat for the orange-throated whiptail. Approximately 226,313 acres (59 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. Management actions will be incorporated into the conservation strategy so that suitable habitat conditions will be maintained.
As described below under Data Characterization, 140 of the recent point localities have a high location precision (precision code 1 or 2). Of these 140 localities, 63 (45 percent) will be conserved within the MSHCP Conservation Area. Conservation of this species will be considered from a landscape perspective because the species has well defined habitat requirements, yet may utilize a wide variety of habitats. Additionally, there are Core Areas for focusing conservation efforts where the species is regularly found.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
ORANGE-THROATED WHIPTAIL
| Vegetation Type1 | MSHCP Plan Area2 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area3 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 217,053 | 49,248 | 86,222 | 135,470 | 47,313 | 34,269 | 81,582 |
| Coastal Sage Scrub | 145,467 | 44,002 | 32,164 | 76,166 | 25,960 | 43,340 | 69,300 |
| Desert Scrubs | 2,230 | 0 | 3 | 3 | 38 | 28 | 66 |
| Riparian Scrub, Woodland and Forest | 13,452 | 3,686 | 6,760 | 10,446 | 349 | 2,655 | 3,004 |
| Riversidean Alluvial Fan Sage Scrub | 5,760 | 2,851 | 1,377 | 4,228 | 187 | 1,344 | 1,531 |
| TOTAL | 383,966 | 99,791 | 126,531 | 226,313 | 73,848 | 81,638 | 155,483 |
| 1 The conservation analysis assumes that 50 percent of these habitat types in the specified Bioregions and elevations are suitable for this species. 2 Total acres only includes lands within the Riverside Lowlands, San Jacinto Foothills, and Santa Ana Mountains Bio-regions below 1,040 m. 3 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
Nothing is known about genetic relationships between orange-throated whiptails within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However, in the absence of data, it is generally thought that it is best to preserve representative populations at the limits of its distribution and range, including longitude, latitude, and elevation. Accordingly, large habitat blocks important to the whiptail are distributed throughout the MSHCP Conservation Area within the following Core Areas: Lake Mathews/Lee Lake (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres), Santa Rosa Plateau (Existing Core F; 8,360 acres), Vail Lake/Aguanga (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), and Anza Valley (Proposed Core 6; 4,290 Acres). All of these contain, or are expected to contain, the habitat requirements necessary to support orange-throated whiptail populations. In addition, linkages between the blocks of habitat will be conserved. In nearly all cases, the linkages would include potential habitat for whiptails. Although minimum dispersal distance is not reported for orange-throated whiptails, Bostic (1965a) found that the mean home range was 0.11 acre. Nearly all core habitat areas are connected by linkages which could support the species. Therefore, it is assumed that most linkages would function as territorial habitat. Thus, genetic exchange would occur incrementally across generations.
Numerous smaller habitat areas would likely be isolated from other habitat by development or high density roadways. These areas include the Jurupa Mountains (Noncontiguous Habitat Block 2; 1,230 acres), Box Springs Mountain (Existing Noncontiguous Habitat Block A and Constrained Linkage 8; 2,920 acres), Steele Peak/Gavilan Hills/Gavilan Plateau (Proposed Linkage 3; 5,540 acres), Sycamore Canyon Regional Park/March Air Force Base (Existing Core D; 2,510 acres), West Hemet (Proposed Noncontiguous Habitat Block 7; 1,250 acres), and Motte-Rimrock Reserve (Proposed Noncontiguous Habitat Block 4; 1,150 acres) among others. These areas are expected to continue to support whiptail populations, though they will be subject to increased predation and at higher risk from stochastic events.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the orange-throated whiptail. The current population size is unknown and estimating population densities is labor intensive.
The MSHCP will conserve large blocks of habitat and interconnecting linkages. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, may be at higher risk of extirpation either rapidly as a result of some catastrophic event, or over the long term as a result of demographic or genetic stochasticity.
In summary, conservation for the orange-throated whiptail will be achieved by the inclusion of at least 226,313 acres of suitable Conserved Habitat within 9 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size of the orange-throated whiptail is unknown, but the general distribution is, and a relatively sizable database is present within the UCR database. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
Approximately 155,483 acres (41 percent) of potential habitat for the orange-throated whiptail would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Seventy-seven (55 percent) of the 140 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However, of these, 16 are mapped within existing agriculture and 22 are located in developed, disturbed land, or water categories. The remaining 39 (51 percent) are in native habitats.
The MSHCP data base includes 213 records for the orange-throated whiptail between 1999 and 1908. Of the 213 records, 81 (38 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 59 (28 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 73 (34 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). A large number of the precision code "1" or "2" records are relatively recent, with 63 (45 percent) since 1990 and 77 (55 percent) pre-dating 1990 or with no associated date. The reason for the lack of more recent locations is likely due to a large historical data base dating to the early 1900s. Abundant information in the literature exists for the orange-throated whiptail, however little or no information exists regarding survivorship, dispersal, and community relationships.
The records are scattered from the Plan Area with records generally lacking from the higher elevations of the Santa Ana Mountains, San Jacinto Mountains, and Aqua Tibia Mountains. Because the records are generally evenly distributed throughout the Plan Area, there are no definable "key" or "core" populations. However, there are a few lightly clustered areas within the Plan Area. These include the Vail Lake area, Lake Elsinore/Canyon Lake area, Lake Mathews/Gavilan Hills area, Lake Skinner area, Badlands, and the Lake Perris area.
Habitat types include chaparral, non-native grassland, (Riversidean) coastal sage scrub, juniper woodland and oak woodland. Associations include alluvial fan scrub and riparian areas. This species is presumably tied to perennial vegetation because its major food source, termites (Bostic 1966b), requires perennial plants as a food base. California buckwheat or flattop buckwheat (Eriogonum fasciculatum), a colonizing species of disturbed, sandy soils, is an important indicator of favorable habitat for C. h. beldingi (McGurty 1981). The presence of E. fasciculatum generally indicates a particular amount of inter-shrub spacing (10 to 40 percent bare ground cover) apparently required for foraging and thermoregulatory behavior of this species (McGurty 1981). E. fasciculatum is known to commonly occur in both coastal sage scrub and chaparral. California sagebrush (Artemisia californica), black sage (Salvia mellifera), and white sage (Salvia apiana) are some of the other plant species that may fill the perennial plant requirement for C. h. beldingi. Friable soil appears to be a necessary requirement for excavating burrows and hiding eggs (Bostic 1965a). Indeed, soil grain size preference data clearly suggest that C. h. beldingi choose only the two finest grain sizes in which to bury (Brattstrom 1989). The usefulness of this data is somewhat limited, as the lizard may choose to bury in loose soil aprons brought up from the sub-surface by rodents, in an otherwise large grain exposure (Brattstrom 1989).
The current range includes southwestern California and Baja California. In California, C. h. beldingi ranges from the southern edges of Orange (Corona del Mar) and San Bernardino (near Colton) Counties southward to the Mexican border. They are located on the coastal slope of the Peninsular Ranges, and extend from near sea level to 1040 m (northeast of Aguanga, Riverside County) (Jennings and Hayes 1994).
The distribution of R. hesperus, C. h. beldingi's primary prey item, curiously delimits certain boundaries of the distribution of the whiptail, where apparently suitable habitat continues. For example, the Peninsular Mountain Range in Riverside and San Diego Counties where R. hesperus is limited to its slopes, possibly restricts eastward and altitudinal expansion of the whiptail populations. Similarly, in San Bernardino, the restriction of R. hesperus to the lower slopes of the transverse and Peninsular Mountain Ranges, and their local scarcity, possibly prevents eastward expansion of whiptails in that county. The fact that Reticulitermes are abundant in Los Angeles and Orange counties, but whiptails are conspicuously absent from these counties, despite the frequency of what appears to be suitable whiptail habitat, suggests that urban, suburban and agricultural development activities serve, in part, as effective dispersal barriers.
More than 50 percent of historic occurrences of C. h. beldingi in west Riverside County are presumed extirpated due to loss of habitat. The remaining range seems to be tied to coastal sage scrub adjacent to flood plains or terraces along streams occurring in western Riverside County. Historic distribution information suggests that orange-throated whiptails were found throughout western Riverside County. Brattstrom (1989), in a status survey conducted for the California Department of Fish and Game, determined that C. h. beldingi is found in parts of the Cahuilla Indian Reservation and Terwilliger Valley, and northwest along the western foothills of the San Jacinto Mountains of Riverside County.
Coastal sage scrub and chaparral, flood plains, and adjacent habitats up to 1,040 meters above mean sea level, within western Riverside County.
Genetics: The critical character that distinguishes the hyperythrus species-group from the other four recognizable species groups in the genus is the presence of a single frontoparietal scale, with all other species of the genus having paired frontoparietal scales (Walker & Taylor 1968).
Grismer (1999) reports that C. hyperythrus currently contains six subspecies, five of which are insular endemics in the Gulf of CA: C. h. carmenensis (formerly caeruleus [Maslin and Secoy 1986]), C. h. pictus, C. h. danheimae, C. h. franciscersis and C. h. espiritensis. C. hyp. hyp. is the only continental taxon and ranges from cismontane Southern CA, southward throughout Baja. It also occurs on the following islands: Pacific islands of Magdalena and Santa Margarita and the islands of San Marcos and Coronados in the Gulf of California.
Diet and Foraging: Bostic (1966) found that C. h. beldingi feed primarily on prey of a secretive nature and low activity (e.g., ants), depending primarily on chemoreception when hunting such prey. When hunting prey of intermediate or high activity (e.g., lepodopterans), vision is most often employed. The stomach contents of 104 Cnemidophorus hyperythrus beldingi were studied. All specimens were collected in San Diego County, California, and Baja California, Mexico from late March 1963 through February 1964. At least 1 percent or more of their diet was found to be comprised of six orders of insects and one order of arachnids. First in importance by a considerable margin was Isoptera (termites). The subterranean termite, Reticulitermes hesperus which comprised approximately 86 percent of all prey consumed, and with one exception, outnumbered all other prey present.
Alternate prey accounted for about 14 percent of all prey consumed. The most important alternate prey item for C, h. beldingi is the spider (Aranedia), which was found by Bostic (1966) to be the next most abundant prey item after termites. Additional alternate prey items, listed in order of importance are: Orthopterans, cockroaches (Blattidae), short-horned grasshoppers (Acrididae), long-horned grasshoppers, crickets; Lepidopterans, pyralid moths (Pyralidae) and their larvae; Neuropterans, antlion larvae; adult Coleopterans, their larvae and pupae, ground beetles (Carabidae) and darkling beetles (Tenebrionidae); and Homopterans, leafhoppers (Cicadellidae) and planthoppers (Fulgoridae). The data indicates that Termites comprised 72 percent - 92 percent of the whiptail diet, with peak consumption occurring simultaneously with the swarming of reproductives in April, and again in July as the result of a single opportunistic individual whose stomach contained nearly half of the termites consumed that month. In late summer, when termites migrate deep into the soil to avoid high surface temperatures, alternate prey items dominate the whiptail's diet. No significant differences in diet between the sexes or between adults and juveniles was found (Bostic 1966).
Daily Activity: Several thermoregulation studies (e.g., Cowles 1940; Carpenter 1961; Bogert 1949; and Fitch 1958) indicate that the daily life cycle of whiptails is dominated and controlled by thermoregulatory needs. By utilizing behavioral thermoregulation, whiptails maintain their body temperatures within a rather narrow range. This indicates that Cnemidophorus hyperythrus is an efficient heliothermic species.
Whiptails are diurnal, but they are also bimodal, spending the warmest portion of the day in shade or an underground retreat (Milstead 1957a; Mitchel 1979; Pianka 1986). During relatively low early morning temperatures, whiptails move slowly while foraging and frequently stop to bask. At this time, much of whiptail activity is confined to open or sparsely covered grass areas between bushes. Basking becomes infrequent and of short duration as midmorning temperatures increase. At this time, foraging largely occurs in shaded or semi-shaded areas around bushes, with travel in open areas occurring very rapidly. Few whiptails are observed foraging as midday temperatures increase. Most retreat to cooler areas (e.g., rodent burrows, shade beneath bushes, or they excavate shallow retreats in the substrate). Additional thermoregulatory behavioral patterns may include arboreal behavior to aid in the dispersal of heat to the cooler upper air strata. Although Bostic (1966b) found that substrate temp appears to play a more important role in regulating body temperature than does that of air.
Rowland (1992) compared observed activity behavior for C. h. beldingi. Over 60 percent of the observations of adults and juveniles occurred while the lizards were in motion. Resting was the second most often observed behavior for this species. He also measured vegetation associations when C. h. beldingi were observed. Adult males were most often observed under Eriogonum, while adult females and juveniles were associated primarily with annuals and grasses, and secondarily with Eriogonum.
As expected, the diurnal cycle fluctuates with seasonality. As temperatures increase through Spring and Summer, whiptails are active both earlier and later in the day. Work by Rowland (1992) at the Motte Rimrock Reserve, in Riverside County, suggests that adult and juvenile C. h. beldingi are generally active eight months out of the year, but juveniles were observed in every month but January. Adults were most active in April and May, while hatchling/juvenile activity was greatest in September. In March and April, adult C. h. beldingi were best observed in the middle of the day (11:00 A.M. to 1:00 P.M.), however, from May through September, individual observations were best made around 2:00 P.M. Activity patterns for adults and juveniles can be best correlated to soil temperature. Mean observed activity levels for adults and juveniles were recorded when ambient daytime temperatures reached between 33-35oC, while soil temperature related activity varied slightly for adults (40oC) and juveniles (36oC).
Other factors such as cloud cover, wind and the moisture content of the soil, that influence ambient temperature, correspondingly influence whiptail activity patterns. Bostic (1966b) observed that partial cloudiness did not interrupt whiptail activity, although on days when the sun did not intermittently shine, no lizards were observed. He also found that intermittent winds up to 20 miles per hour (mph) and steady winds up to 8 mph did not affect activity. Steady winds above 10 mph were found to result in a significant reduction in the number of individuals observed. Rowland (1992) also found that cloud cover may influence C. h. beldingi activity. Adult activity was greatest during surveys conducted between 61-80 percent cloud cover, while juveniles were most active during surveys conducted between 81-100 percent cloud cover. Wind speed was also a factor limiting activity of this species. Both adult and juvenile C. h. beldingi were most active when wind speeds were <5 miles per hour.
Adult whiptails usually enter into hibernation in late July through most of September, and immatures in December (Bostic 1966b). Hibernation, and likely oviposition sites, occur on well isolated, south facing slopes (Jennings and Hayes 1994).
Reproduction: Unlike several species in the genus Cnemidophorus, C. h. beldingi does not reproduce parthenogenetically. Details of the reproductive cycle of C. h. beldingi have been deduced through examination of reproductive structures throughout the year (Bostic, 1966a). Males were found to be reproductively active from the first week of April through the first week of July based on the presence of enlarged testes during this period. The male cycle begins with regressed testes as they emerge from hibernation. In late April, maximum testis volume is achieved. Thereafter, there is a decrease in testes volumes throughout the rest of the summer, with testes regression ceasing in August. Whiptails were generally found to reach maturity in the Spring following hatching in the previous Summer based on examination of the gonads and accessory reproductive structures of the dissected lizards. In yearlings, reproductive potential is lower than in adults of two years of age or older. Bostic (1966a) recorded a maximum clutch size of 2 eggs for yearlings and 3 for older lizards.
The average clutch size for C. hyperythrus is approximately 2.3 (Bostic 1966a) which is similar to average clutch sizes recorded by Fitch (1958) for C. sexlineatus; 3.03. The number of egg clutches deposited each season by whiptails in not known, however, multiple clutches may be laid, one in June and again in mid-July (Milstead 1957b; Bostic 1966c; Parker 1972; Crews, et al. 1986). Rainfall may influence clutch size (Mitchel 1979; Crews, et al. 1986; Pianka 1986). Incubation of hatchlings is suspected to be approximately 50-55 days based on time intervening between the last record of females with oviducal eggs (mid-July) to dates hatchlings were last observed in the field.
Survival: The development of speed in Cnemidophorus considerably reduces the danger of predation and overheating; however, there is no data regarding survivorship.
Dispersal: There is no information regarding dispersal requirements or rates.
Socio-Spatial Behavior: Bostic (1965a) recorded an average home range of 0.11 acre for adult C. h. beldingi, which is considerably smaller than the average home ranges of 0.26 acre (0.57 acre when extended forays are included), 0.24 acre and 0.995 acre respectively recorded by Milstead (1957b), Fitch (1958) and Jorgenson and Tanner (1963) for larger species of Cnemidophorus. Data suggest that females have significantly larger home ranges than males, although no statistically significant difference was found (probably due to inadequate sample size). The mean home range size for females was approximately 2.1 times larger than the mean home range for males. Consequently, it was found that female home ranges extensively overlap and superimpose with each other as well as overlap male ranges. "Overlap, but not superimposition of male home ranges was also recorded" (Bostic 1965).
Community Relationships: There is no information available regarding community relationships, though it is likely to be predated on advantageously by numerous snakes, predatory birds, and mammals. It is also likely that orange-throated whiptails compete with orange-throated whiptails for resources.
Habitat destruction is likely the major cause of the decline of C. h. beldingi populations. Despite what appears to be abundant suitable whiptail habitat, urban and agricultural development may serve as effective dispersal barriers (Bostic 1966a). Argentine ants (Irdomyrmex humilis) are an invasive exotic species known to displace many native insects, and may influence the food base of C. h. beldingi (Jennings and Hayes 1994). Excessive prescribed burning can lead to increased exposure to predation due to modification of the canopy profile, and can ultimately lead to type conversion from coastal sage scrub and chaparral to non-native grassland (McGurty 1981). In addition, repeated reduction of normally abundant woody fuels has a direct effect on western subterranean termite (Reticulitermes hesperus) presence, the nearly exclusive food-prey source of C. h. beldingi. Further threats include irreversible habitat destruction resulting from land-filling or artificial channelization of natural drainage bottoms, which likely serve as foraging and dispersal areas for this species.
Unlike several species in the genus Cnemidophorus, C. h. beldingi does not reproduce parthenogenetically.
Bogert C.M. 1949. Thermoregulation in reptiles, a factor in evolution. Evolution 3 (3):195-211.
Bostic, D. L. 1965a. The home range of the teiid lizard, Cnemidophorus hyperythrus beldingi. The Southwest Naturalist 10(4):278-281.
Bostic, D. L. 1966a. Thermoregulation and hibernation of the lizard, Cnemidophorus hyperythrus beldingi (Sauria: Teiidae). The Southwestern Naturalist. 11(2):275-289.
Bostic, D. L. 1966b. Food and feeding behavior of the teiid lizard, Cnemidophorus hyperythrus beldingi. Herpetologica 22(1):23-31.
Bostic, D. L. 1966c. A preliminary report on the reproduction of the teiid lizard, Cnemidophorus hyperythrus beldingi. Herpetologica 22(2):81-90.
Brattstrom, B. H. 1989. Status survey of the Orange-throated Whiptail, Cnemidophorus hyperythrus beldingi, and the San Diego Horned Lizard, Phrynosoma coronatum blainvillei. Progress report on Fish and Game Contract FG 8597.
Carpenter, C.C. 1961. Temperature relationships of two Oklahoma lizards. Proc. Okla. Acad. Sci. 41: 72-77.
Cowles, R.B. 1940. Additional implications of reptilian sensitivity to high temperatures. Amer. Nat. 74 (755): 542-561.
Crews, D., M. Grassman, and J. Lindzey. 1986. Behavior facilitation of reproduction in sexual and unisexual whiptail lizards. Proc. Nat. Acad. Sci. 83:9547-9550.
Fitch, H.S. 1958. Natural History of the six-lined race-runner (Cnemidophorus sexlineatus). Univ. Kan. Publ. Mus. Nat. Hist. 11 (2):11-62.
Grismer, L., Lee. 1999. Phylogeny, Taxonomy, and Biogeography of Cnemidophorus hyperythrus and C. ceralbensis (Squamata: Teiidae) in Baja CA. Herpetologica. 55:28-41.
Jennings, M. R., and M. P. Hayes. 1994. Amphibian and reptile Species of Special Concern in California. Final report submitted to California Department of Fish and Game, Inland Fisheries Division, Rancho Cordova, California, under Contract 8023.
Jorgensen, C.D. and Tanner, W.W. 1963. The application of the density probability function to determine the home ranges of Uta stansburiana and Cnemidophorus tigris tigris. Herpetologia 19: 105-115.
Maslin, T.P., and D.E. Secoy. 1986. A checklist of the lizard genus Cnemidophorus (Teiidae). Contributions to zoology. Univ. Colorado Museum. 1:1-60.
McGurty, B. M. 1980. Preliminary review of the status of the San Diego horned lizard, Phrynosoma coronatum blainvillei, and the orange-throated whiptail, Cnemidophorus hyperythrus beldingi. Report for the California Department of Fish and Game, Inland Fisheries Division, Rancho Cordova, California, under Contract.
McGurty B.M. 1981. Status survey report on the orang-throated whiptail lizard, Cnemidophorus hyperythrus beldingi occurring on Camp Pendleton U.S. Marine Corps Base, Miramar U.S. Naval Air Station, and Fallbrook Annex U.S. Naval Weapons Station during the survey period August to November 1981. Contract 11310-0129-81. San Diego, California.
Milstead, W. W. 1957a. Observations on the natural history of four species of whiptail lizard, Cnemidophorus (Sauria, Teiidae) in Trans-Pecos Texas. Southwest Naturalist 2:105-121.
Milstead, W. W. 1957b. Some aspects of competition in natural populations of whiptail lizards (genus Cnemidophorus). Texas J. Sci. 9:410-447.
Mitchell, J. C. 1979. Ecology of southeastern Arizona whiptail lizards (Cnemidophorus: Teiidae): population densities, resource partitioning, and niche overlap. Can. J. Zool. 57:1487-1499.
Parker, W. S. 1972. Ecological study of the western whiptail lizard, Cnemidophorus tigris gracilis, in Arizona. Herpetologica 28:360-369.
Pianka, E. R. 1986. Ecology and natural history of desert lizards. Princeton University Press, Princeton.
Rowland, S. D. 1992. Activity, behavior, ecology, and home range of the orange-throated whiptail, Cnemidophorus hyperythrus beldingi Cope. MA Thesis, California State University, Fullerton, California.
Stejneger, L. 1893. Annotated List of the reptiles and Batrachians collected by the Death Valley Expedition in 1891 with descriptions of new species. N.A. Fauna, No.7 pp.159-228, pls. 1-4.
Walker, J.,M., and Taylor, H.,L. 1968. Geographical Variation in the Teiid Lizard Cnemidophorus hyperythrus. I. The caeruleus-like subspecies. The American Midland Naturalist. V.80. No. 1. Pp. 1-27.
coastal western whiptail (Cnemidophorus tigris multiscutatus)
State: Species of Special Concern
Federal: None
The coastal western whiptail population is widespread throughout the Plan Area. The coastal western whiptail occurs in a wide variety of habitats including coastal sage scrub, desert scrub, Riversidean alluvial fan scrub, woodlands, grasslands, playas, and respective ecotones between these habitats. The species is common in most areas of the Plan Area, including the fringes of urbanized areas. Existing data suggests it may occur at all elevation levels within the Plan Area. No specific management regimes are needed to maintain this species, although management of habitat for species such as the California gnatcatcher, Stephens' kangaroo rat, San Bernardino kangaroo rat, and Los Angeles pocket mouse may benefit the coastal western whiptail.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 142,117 acres of coastal sage scrub, desert scrub, Riversidean alluvial fan scrub, woodlands, grasslands, and playas. The majority of habitat conservation will occur in large blocks within the Plan Area.
Include within the MSHCP Conservation Area at least 13 Core Areas at the Santa Rosa Plateau (8,360 acres), Lake Skinner-Diamond Valley Lake (29,020 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake (50,000 acres), Anza Valley (4,290 acres), Agua Tibia Wilderness (10,460 acres), Santa Ana Mountain foothills (71,490 acres), Santa Ana River (10,740 acres), and Paloma Valley/Hogbacks (5,050 acres).
Include within the MSHCP Conservation Area linkages between large habitat areas, including contiguous uplands from Estelle Mountain to Wildomar, Gavilan Hills, San Jacinto River, Kolb Creek/Arroyo Seco, Temecula Creek, Tucalota Creek, Wilson Creek, Tule Creek, and San Gorgonio Wash.
For purposes of this conservation analysis, potential habitat for the coastal western whiptail includes coastal sage scrub, desert scrub, grassland, Peninsular juniper woodland and scrub, playas and vernal pools, and Riversidean alluvial fan sage scrub at all elevation levels within the Plan Area. Based on these habitats, the Plan Area supports approximately 325,078 acres of potential habitat for the western whiptail. Table 1 shows the conservation of potential habitat for the western whiptail. Approximately 142,117 acres (44 percent) of suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the coastal western whiptail. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
As described below under Data Characterization, 54 of the 104 data points have a precision of "1" or "2." Of these 54 locations, 18 (33 percent) would be within the MSHCP Conservation Area. Conservation of this species should be considered from a landscape perspective because the species is found throughout the Plan Area and may occur in a variety of open habitats. While there are definable locations for focusing conservation efforts, there do not appear to be any significant key populations that would be essential for conservation of the species.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
COASTAL WESTERN WHIPTAIL
| Vegetation Type | MSHCP Plan Area (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area1 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Coastal Sage Scrub | 152,686 | 47,161 | 34,555 | 81,716 | 26,241 | 44,729 | 70,970 |
| Desert Scrubs | 9,378 | 3,675 | 1,314 | 4,989 | 44 | 4,345 | 4,389 |
| Grassland | 146,869 | 20,011 | 22,806 | 42,817 | 12,223 | 91,829 | 104,052 |
| Peninsular Juniper Woodland and Scrub | 1,082 | 336 | 274 | 610 | 23 | 450 | 473 |
| Playas and Vernal Pools | 7,914 | 3,828 | 2,923 | 6,751 | 0 | 1,163 | 1,163 |
| Riversidean Alluvial Fan Sage Scrub | 7,149 | 3,171 | 2,063 | 5,234 | 217 | 1,697 | 1,915 |
| TOTAL | 325,078 | 78,182 | 63,935 | 142,117 | 38,748 | 144,213 | 182,962 |
| 1 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. | |||||||
Nothing is known about genetic relationships between coastal western whiptail within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However, it is generally thought that in the absence of data, it is best to preserve representative populations at the limits of its distribution and range, including latitude, longitude, and elevation. Accordingly, large habitat blocks important to the whiptail are distributed throughout the MSHCP Conservation Area within the following Core Areas: Lake Mathews/Lee Lake (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres), Santa Rosa Plateau (Existing Core F; 8,360 acres), Vail Lake/Aguanga (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Wilderness (Existing Core M; 10,460 acres), Santa Ana Mountains foothills (Existing Core B; 71,490 acres), Santa Ana River (Existing Core A; 10,740 acres), and Paloma Valley/Hogbacks (Proposed Core 2: 5,050 acres). All of these contain, or are expected to contain, the habitat requirements necessary to support western whiptail populations. In addition, linkages between the blocks of habitat will be conserved. In nearly all cases, the linkages would include potential habitat for whiptails. Although minimum dispersal distance is not reported for western whiptails, the diameter of Anderson's (1993) calculation of western whiptail home range (1 ha), would be approximately 350 feet. Nearly all core habitat areas are connected by linkages which are greater than this distance. Therefore, it is assumed that most linkages would function as territorial habitat. Thus, genetic exchange would occur incrementally across generations.
Numerous smaller habitat areas would likely be isolated from other habitat by development or high density roadways. These areas include the Jurupa Mountains (Proposed Noncontiguous Habitat Block 2; 1,230 acres), Box Springs Mountain (Existing Noncontiguous Habitat Block A and Proposed Constrained Linkage 8; 2,920 acres), Steele Peak/Gavilan Hills/Gavilan Plateau (Proposed Linkage 3; 2,920 acres), Sycamore Canyon Regional Park/March Air Force Base (Existing Core D; 5,540 acres), West Hemet (Proposed Noncontiguous Habitat Block 7; 1,250 acres), and Motte-Rimrock Reserve (Proposed Noncontiguous Habitat Block 4; 1,150 acres) among others. These areas are expected to continue to support whiptail populations, though they will be subject to increased predation and at higher risk from stochastic events. However, some connections will be preserved by the following linkages between large and small Core Areas: Estelle Mountain to Wildomar, Gavilan Hills, San Jacinto River, Kolb Creek/Arroyo Seco, Temecula Creek, Tucalota Creek, Wilson Creek, Tule Creek, and San Gorgonio Wash among others.
Movement across large roads and freeways will be hindered in areas without large vehicular overpasses. It is unlikely that reptiles, including the coastal western whiptail, will utilize long and narrow undercrossings to occupy new habitat and over-road movement of reptiles will likely result in mortality. Some successful movement of reptiles is expected under bridges greater than 50 feet in length.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the coastal western whiptail. The current population size is unknown, but the western whiptail appears to be common in suitable habitat, as evidenced by its widespread distribution.
The MSHCP will conserve large Core Areas and interconnecting habitat linkages that are suitable for occupation by the western whiptail in the large habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, may be at higher risk of extirpation either rapidly as a result of some catastrophic event, or over the longer term as a result of demographic or genetic stochasticity (e.g., random birth and death rates, inbreeding depression, genetic drift).
Nothing is known about genetic relationships between western whiptails within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However, in the absence of data, it is generally thought that it is best to preserve representative populations at the limits of its distribution and range, including longitude, latitude, and elevation.
In summary, conservation for the western whiptail will be achieved by the inclusion of at least 142,117 acres of suitable Conserved Habitat within 13 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size of the western whiptail is unknown, but the general distribution is, and a relatively sizable database is present within the UCR database. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
Approximately 182,962 acres (56 percent) of potential habitat for the western whiptail would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Thirty-six (67 percent) of the 54 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However of these, 16 (44 percent) are mapped within existing agriculture, 6 (17 percent) are located in developed or disturbed habitat coverages, and 14 (39 percent) are in chaparral, coastal sage scrub, woodlands and forests, and non-native grassland habitats.
The MSHCP data base includes 104 records for the whiptail between 1999 and 1972. Of the 104 records, 34 (33 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 20 (19 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 50 (52 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). Most of the records are relatively recent, with 41 (74 percent) since 1990 and 13 (26 percent) pre-dating 1990 or with no associated date. The reason for the abundance of more recent locations is likely due to increased survey effort and awareness of declining species. A moderate amount of information is known about C. tigris, though nothing is known about dispersal requirements.
The records are scattered from the Plan Area with records generally lacking from the higher elevations of the Santa Ana Mountains and San Jacinto Mountains. Because the records are generally evenly distributed throughout the Plan Area, there are no definable "key" or "core" populations. However, there are a few clustered areas within the Plan Area. These include the Beaumont/ Cherry Valley area, Murrieta Hot Springs/ French Valley area, Lake Skinner/ Eastside Reservoir area, Lake Elsinore area, Lake Mathews area, and March Air Reserve Base/Moreno Valley area.
The western whiptail can be found in open, often rocky areas with little vegetation or sunny microhabitats within shrub or grassland associations (Benes, 1969). Cnemidophorus is commonly found on the eastern and western slopes of the San Gabriel Mountains in all habitats except yellow pine forest (Schoenherr, 1976). Schoenherr (1976) also indicates that the western whiptail probably occurs in oak woodland (although none have been taken in this habitat type) because they have been detected in riparian areas.
The western whiptail ranges through the semi-arid and arid desert lowlands of southern California, southern Arizona, adjacent areas of Mexico and western Baja California, Mexico (Lowe, et al., 1970). It is the third most common lizard in the San Gabriel Mountains after Sceloporus occidentalis and Uta stansburiana (Schoenherr, 1976). No elevation limit within the Plan Area was apparent in the literature (Fisher and Case, 1997a).
Occurrences have been documented throughout Western Riverside County in suitable habitat. Population clusters exist south and east of Lake Skinner and extending north toward the Eastside Reservoir, also east of Lake Mathews from I-15 to Riverside, and west of Temecula and Murrieta. Additional localities include Potrero Creek, Cactus Valley, Crown Valley, and Motte Reserve.
Open grassland/coastal sage scrub habitats throughout the Plan Area.
Genetics: There is no information regarding genetics.
Diet and Foraging: Prey items of the western whiptail include termites, scorpions, solfugids, cockroaches, antlion larvae, and various insect eggs, larvae, and pupae (Anderson, 1993). In general, foraging individuals are usually on the move, foraging in discrete patches and capturing sedentary, hidden prey that were often detected by chemoreception. The prime foraging location of the whiptail lizard is under perennials where a host of invertebrate prey can be found. Most invertebrate prey are processed and swallowed rapidly. The most time-consuming of all prey captures observed by Anderson (1993) was the capture of termites, which was accomplished typically by digging. Approximately 88 percent of prey captured was fossorial, or hidden and inactive.
Western whiptails generally use several types of prey capture techniques including digging, picking up exposed prey, general searching, scratching, and chasing exposed mobile prey (Anderson, 1993). Digging was the most prevalent capture technique at 72 percent of the observed attempts and 114 of 188 captures. Whiptails usually excavate a hole less than 5 cm in diameter and a few centimeters deep at a single location (Anderson, 1993). The second most common capture technique (42 of 188 captures) was picking up either slow-moving or sedentary exposed prey. General searching involves careful visual and chemosensory inspection of the area within a few body lengths of the animal and seems responsible for the discovery and capture of exposed prey. Scratching in leaf litter or loose soil was a common method employed, but resulted in very few captures. Chasing of exposed mobile prey was as common as picking up exposed prey, but was successful in only about 30 percent of all cases. Usually less than 0.25 meters separated the whiptail from the prey when chasing occurred.
Daily Activity: The daily activity period of C. tigris individuals consists of nearly continuous movement associated with the search for prey with activity peaks in the morning and afternoon. They can be characterized as terrestrial, fusiform, diurnal, and actively foraging lizards (Anderson, 1993).
The manner in which whiptails utilize their environment is affected by body size. This is a result of the rate of heat exchanged with the environment relative to body size (surface/mass ratio). This factor plays a relatively direct role in determining the thermospatial niche of these lizards. A larger whiptail, like C. tigris behaviorally compensates for its relatively greater heat retention relative to smaller species by occupying cooler portions of the thermal mosaic for a greater percentage of time abroad than does a smaller Cnemidophorus. Activity becomes increasingly concentrated in the shade as the day becomes increasingly hotter and is eventually restricted to the coolest shade before the animal retreats to a burrow to escape the midday peak in temperature. Field and laboratory studies by Asplund (1974) show that larger lizards bask less and spend more time in the shade than do smaller lizards with the same thermal preference and tolerance limits.
During the course of aboveground activity, the desert forms of C. tigris normally utilize shade from all portions of the vegetation for thermoregulation (Asplund 1974). In sufficiently cool habitats, large size can be a disadvantage due to the longer basking time required to achieve activity temperature relative to smaller species. This is evident during the rainy season when insect prey are more abundant, smaller Cnemidophorus species are allowed greater levels of activity.
Data on seasonal activity varies with location. Pequegnat (1951) states that the most active periods for this lizard in the Santa Ana Mountains occur during early and late Summer, and that they are seldom detected during late June, July and early August. Schoenherr (1976) reports that whiptail lizards first appear in the San Gabriels during April and May, increasing their activity until June and remaining abundant and active all Summer. The number of active individuals tapers off in September and activity ceases altogether in October (Schoenherr, 1976).
Bogert (1949) recorded a mean body temp of 41.3 degrees C (+/- 0.24) for C. tigris living in Arizona.
Reproduction: In temperate zone populations, the reproductive season generally begins in May (earlier at Desert Center, Riverside Co., CA; Anderson and Karazov 1988). Mean clutch size of C. tigris varies from 2.1 to 4.0 (Garland 1993). Length of reproductive season appears to influence clutch frequency. Length of reproductive season is likely influenced by rainfall, temperature, resources for reproduction, suitable microenvironmental conditions for egg development, and adequate resources for hatchlings. Geographic variation in clutch and body size in C. tigris is not correlated with latitude. The data suggests that larger clutches are produced at higher latitudes and higher elevations than at lower latitudes or elevations (Garland, 1993). Female body size is the major factor determining clutch and egg size.
Survival: Thermoregulatory needs dominate the daily life cycle of whiptails. To compensate for extreme temperature changes in their environment, whiptails maintain their body temperatures within a rather narrow range by behavioral thermoregulation. Bostic (1966b) found that substrate temperature appears to play a more important role in regulating body temperature than does that of air. Adult and immature whiptails usually enter into hibernation in late July; adults hibernate through most of September while immature whiptails hibernate through December (Bostic 1966b).
Dispersal: There is no information available regarding dispersal.
Socio-Spatial Behavior: Spatial behavior is directly related to body size via the rate of heat exchanged with the environment. Asplund (1974) observed that Variation in body size in Cnemidophorus may reflect adaptation to differences in the structure of vegetation, relatively larger lizards being more successful in relatively shaded habitats. Conversely, "smaller body size in whiptails constitutes an adaptation to the desert with respect to the distinctive structure of desert vegetation" (Asplund 1974). Consequently, ontogenetic segregation of a species occurs in anyone habitat, with different thermospatial niches being occupied by sympatric species pairs that differ in body size. Asplund (1974) found no behavioral evidence that the larger whiptail lizards have evolved physiological thermoregulation that capitalizes on metabolic heat production.
Anderson (1993) found that the home range for the western whiptail was quite large (1.0 ha for males; 0.32 ha for females).
Community Relationships: There is no information available regarding community relationships.
Habitat loss due to development, widespread use of insecticides, off-road vehicle use, and genetic isolation.
Within their preferred habitat, some means of sheltering in the shade of rocks or vegetation for thermal regulation is requisite (Milstead 1947).
Anderson, R.A. 1993. An analysis of foraging in the lizard Cnemidophorus tigris. IN: J.W. Wright, and L.J. Vitt (Eds.) 1993. Biology of the Whiptail Lizards (Genus Cnemidophorus). Oklahoma Mus. Nat. Hist., Norman, Oklahoma, USA.
Anderson, R.A. 1994. Functional and population responses of the lizard Cnemidophorus tigris to environmental fluctuations. American Zoologist 34:409-21.
Anderson, R.A., and W.H. Karasov. 1988. Energetics of the lizard, Cnemidophorus tigris and life history consequences of food-acquisition mode. Ecol. Monogr. 58:79-110.
Asplund, K.K. 1974. Body Size and habitat Utilization in Whiptail Lizards. Copeia 1974. No. 3. Pp. 695-702.
Benes, E.S. 1969. Behavioral evidence of color discrimination by the whiptail lizard, Cnemidophorus. Copeia 1969:707-722.
Bogert, C.M. 1949. Thermoregulation in reptiles, a factor in evolution. Evolution 3 (3):195-211.
Cope, E.D. 1892. A synopsis of the species of the teiid genus Cnemidophorus. Trans. Amer. Phil. Soc. 17:27-52.
Fisher, R.N., and T.I. Case. 1997a. Survey of reptile and amphibian species at risk in southern California forests. Final report to U.S. Forest Service, Department of Agriculture. 16 pp+ appendix
Fisher, R.N., and T.J. Case. 1997b. A Field Guide to the Reptiles and Amphibians of Coastal Southern California.
Garland, T. Jr. 1993. Locomotor performance and activity metabolism of Cnemidophorus tigris in relation to natural behaviors. IN: J.W. Wright, and L.J. Vitt (Eds.) 1993. Biology of the Whiptail Lizards (Genus Cnemidophorus). Oklahoma Mus. Nat. Hist., Norman, Oklahoma, USA.
Heyer, W.R., M.A. Donnelly, R.W. McDiarmid, L.C. Hayak, and M.S. Foster. 1994. Measuring and monitoring biological diversity. Standard methods for amphibians. Smithsonian Institution. Press. Washington, USA. 364 pp.
Lowe, C.H., C.J.C.Wright, and R.L. Bezy. 1970. Chromosomes and evolution of the species groups Cnemidophorus (Reptilia: Teiidae). Syst.Zool 19 (1970): 128-141.
Pianka, E.R. 1970. Comparative autoecology of the lizard Cnemidophorus tigris in different parts of its geographic range. Ecology 51:703-720.
Pianka, E. R. 1986. Ecology and natural history of desert lizards. Princeton University Press, Princeton.
Pequegnat, W.E. 1951. The biota of the Santa Ana Mountains. Journal of Entomological Zoology (Pomona) 42, no. 3/4 (1951): 1-84.
Schoenherr, A.A. 1976. The Herptofauna of the San Gabriel Mountains Los Angeles, California Including Distribution and Biogeography. Special Publication of the Southwestern Herpetologist's Society, February 1, 1976.
Stebbins, R. C. 1985. A field guide to western reptiles and amphibians. McGraw Hill Book Company, New York, New York.
granite night lizard (Xantusia henshawi henshawi)
State: Species of Special Concern
Federal: None
Granite night lizards occur in localized populations distributed east of Interstate 215, but primarily within the eastern portion of the Plan Area. Localized populations are often found in flaking granite, rock outcrops, and boulderfields, most commonly with chaparral, sage scrub, mixed conifer forest, and oak woodland. Though they primarily occupy these features, granite night lizards have been documented in outlying habitat. No specific management regimes have been identified to maintain adequate habitat for this species. Because granite night lizards occur in localized conditions and secretive and difficult to detect, it will require some site specific management or monitoring activities.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 297,143 acres of chaparral, sage scrub, coniferous forest, and oak woodland in the eastern portion of the Plan Area (east of Interstate 215). Acreage conserved will include linkages between conserved areas, and the rocky outcrops, flaking granite, and boulderfields that are a limiting habitat feature for this species.
Include within the MSHCP Conservation Area at least 9 Core Areas at the Lake Skinner-Diamond Valley Lake (29,070 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake/Wilson Valley (50,000 acres), Agua Tibia Mountains (10,460 acres), San Jacinto Mountains (140,000 acres), and Anza Valley (4,290 acres).
As described below, the granite night lizard may be found in almost any habitat where granitic boulders occur, but is most commonly associated with chaparral, coastal sage scrub, coniferous forests, and oak woodland habitats between 130 and 1,200 m in elevation. For the purpose of this conservation analysis, we have considered the primary habitat of the species to include chaparral, sage scrub, coniferous forest, and oak woodland habitats where regions of flaking granite, rock outcrops, or boulderfields occur between 130 and 1,200 m and east of Interstate 215. Based on these habitats and restrictions, the Plan Area supports approximately 494,181 acres of potential habitat for the granite night lizard. Table 1 shows the conservation of potential habitat for the granite night lizard. Approximately 297,143 acres (60 percent) of the potential habitat in the Plan Area would be conserved in the MSHCP Conservation Area which might support the requisite granite and boulder microhabitat conditions. It is assumed that these lands would be managed for wildlife resources including the granite night lizard. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
As described below under Data Characterization, 38 of the 47 data points have a precision of "1" or "2." Of these 38 locations, 10 (26 percent) would be within the MSHCP Conservation Area. Conservation of this species has been considered from a landscape perspective because the species may be found throughout the eastern portion of the Plan Area within suitable habitat (rock outcroppings). It is estimated that approximately one-fifth of the MSHCP Plan Area supports suitable granitic rock outcrops. The reserve design conserves approximately the same percentage of rock outcrops within habitat that is suitable for this species. While there are definable locations for focusing conservation efforts, there does not appear to be any specific key populations that are essential for conservation of the species. It is likely that populations will persist within the eastern portion of the Plan Area (east of Interstate 215) wherever rock outcrops exist within suitable habitat for the species.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
GRANITE NIGHT LIZARD
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 311,585 | 61,879 | 135,130 | 197,009 | 57,779 | 56,797 | 114,576 |
| Coastal Sage Scrub | 151,007 | 47,125 | 33,095 | 80,220 | 26,225 | 44,562 | 70,787 |
| Desert Scrubs | 5,308 | 2,843 | 362 | 3,205 | 43 | 2,060 | 2,103 |
| Montane Coniferous Forest | 689 | 0 | 687 | 687 | 1 | 1 | 2 |
| Riversidean Alluvial Fan Sage Scrub | 6,835 | 3,150 | 1,953 | 5,103 | 217 | 1,515 | 1,732 |
| Woodlands and Forest | 18,757 | 2,387 | 8,532 | 10,919 | 4,892 | 2,946 | 7,838 |
| TOTAL | 494,181 | 117,384 | 179,760 | 297,143 | 89,157 | 107,881 | 197,038 |
| 1 Total acres include habitat between 130 and 1,200 meters in elevation which are east of Interstate 215. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
Several large blocks of habitat supporting the granite night lizard will be conserved throughout the MSHCP Conservation Area within the following Core Areas: Vail Lake/Sage/Wilson Valley (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Mountains (Existing Core M; 10,460 acres), and the San Jacinto Mountains (Remaining bulk of Existing Core K: 140,000 acres). Maintenance of rock outcrop clusters and rows is important for this species. A recent genetic study on the granite night lizard shows that the species is divided into three haploclades with high degrees of sequence divergence (Lovich, 2001). The three habploclades are separated geographically by the San Jacinto and Elsinore fault zones and their associated geophysical features (e.g., canyons and valley floors). Two of the three haploclades occur within the Plan Area and are separated by the San Jacinto fault zone. One haploclade occurs in the Santa Rosa and San Jacinto Mountains, and the other occurs in the Lake Perris region. Because of this variability that is detectable at a genetic level, it is important to conserve representative populations at the limits of the species distribution and range, including longitude, latitude, and elevation. To this end, the MSHCP Conservation Area contains conserved Core Areas within habitat that is suitable for this species at all cardinal compass points and at varying elevation ranges. All of these contain, or are expected to contain, the habitat requirements necessary to support healthy granite night lizard populations.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above and the adaptive management program as described below, will maintain viable populations of the granite night lizard within the MSHCP Conservation Area. The current population size and status of the granite night lizard population in the Plan Area is unknown.
In summary, conservation for the granite night lizard will be achieved by the inclusion of at least 297,143 acres of suitable Conserved Habitat within 9 Core Areas which are composed of large blocks of habitat distributed throughout the MSHCP Conservation Area and the species range within the Plan Area. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. Although the current population size of the granite night lizard is unknown, the general distribution is known. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
The Incidental Take of the granite night lizard is difficult to quantify due to our limited knowledge of the species distribution within the Plan Area and the fact that losses may be masked by natural fluctuations in abundance and distribution during the life of the permit. However, the maximum level of Take for this species can be anticipated by the loss of the number of acres of habitat that will become unsuitable for the species. Approximately 197,038 acres (40 percent) of potential habitat for the granite night lizard would be outside the MSHCP Conservation Area and individuals within this habitat will be subject to Take consistent with the Plan. Twenty-eight (74 percent) of the 47 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However of these, 5 (18 percent) are mapped within existing developed or disturbed land coverages. The remaining 23 (82 percent) are in natural habitats.
The MSHCP data base includes 47 records for the granite night lizard between 1997 and 1933. Of the 47 records, 11 (23 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 27 (58 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 9 (19 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). Only a few of the precision code "1" or "2" records are relatively recent, with 5 (11 percent) since 1990 and 42 (89 percent) pre-dating 1990 or with no associated date. A fair amount of information exists in the literature, for the granite night lizard. However, there is little if any information available regarding survivorship, dispersal, and socio-spatial behavior. This level of detail is probably sufficient for a species dependant on a specific microhabitat feature (fractured granitic rock in this case). Based on the species secretive nature, a number of the older points may still be reliable if the habitat still exists.
The few records are lightly scattered throughout various high points in the Plan Area. Apparent clusters or "core" areas appear to be the results of single survey efforts or studies. It appears that few surveys have been conducted and those that have, were not all inclusive. It is estimated that approximately one-fifth of the MSHCP Plan Area supports granitic outcrops.
Xantusia henshawi henshawi is restricted to narrow microenvironment conditions (Bezy 1972) where it is rarely found far from rock outcrop crevices (Lee 1975). The locally common, but patchily distributed lizard (Lee 1976; Holland and Goodman 1998) is found exclusively in areas of massive rocks, rock outcrops, and flaking granite, in a variety of desert, chaparral, and woodland habitats (Zeiner et al. 1988). It takes cover in cracks and crevices and can be found under flakes and slabs of exfoliating granite (Lee 1974; Zeiner et al. 1988). It is almost completely confined to granodiorite or metavolcanic rocky areas within suitable habitats (Lee 1973; Grismer and Galvan 1986; Bezy 1988). Lee (1973b; 1975) found that most of the suitable rock outcrop habitat type used by the lizard is primarily within chaparral habitats, with chaparral-coastal sage scrub and chaparral-creosote bush ecotonal areas also occupied (Lee 1973b; 1975). However, it may utilize grasslands and other habitats between suitable outcrops for movement (Holland and Goodman 1998).
Xantusia henshawi henshawi ranges from southern California (South Cabazon, Riverside County [Glaser 1970]) south into northern Baja California, Mexico (Arroyo Encanto, Baja California Mexico [Lee 1976]). The lizard can be found in arid and semi-arid habitats on the coastal and desert slopes of the Peninsular Ranges, occupying the San Jacinto Mountains and Santa Rosa Mountains (Riverside County), Laguna Mountains (San Diego County), and the San Pedro Martir Mountains (Baja California Del Norte, Mexico). Its elevational range is from 130 to 1200 m in California (Zeiner et al. 1988) though Lee (1976) indicates that it reaches 2250 m, presumably in Mexico.
Historic populations of Xantusia henshawi henshawi are known to occur in southern Banning (Bezy 1972) and within a band that appears to wrap around the Banning area south along the base of San Jacinto Mountain, through the Pine Meadow area, to the west around the Wilson Creek/Vail Lake/Aguanga area, and also south into the Cleveland National Forest (Lee 1975; 1976). The MSHCP data base also show populations occurring in San Jacinto, southwest of the San Jacinto River and north of Hemet, around the Cactus Valley area, in the vicinity of Sage, and in Winchester. A number of these points appear to be outside the known range of the species in areas which probably do not support their narrow ecological requirements; therefore, the more centrally-located points should be scrutinized carefully for appropriate habitat features.
Key population areas occur at locations within the known band of occupied habitat as outlined by Lee (1975), Bezy (1972) where fractured rock situations occur, and locations east of the Interstate 215 (Lovich, 2001).
Genetics: Xantusia henshawi was initially described by Stejeger in 1893, based on a specimen captured by H.W. Henshaw in May 1893. Cope (1895) described the synonym, Xantusia picta based on a specimen captured by Frank Blaidell. These were later combined by Van Denburgh in 1916. Webb (1970) added a trinomial creating X. h. henshawi and X. h. bolsonae based on morphological characters. In 1986, Grismer and Galvan described an additional subspecies, X. h. gracilis based on morphological characters, isolation, and habitat preferences. Bezy (1972) conducted a study of the various karyotypes within the Xantusia genus. He found that there was karyotypic variation within the Xantusia henshawi species. Additionally, based on karyotype phylogeny, X. henshawi appears to have derived from X. vigilis and is closely related to X. riversiana. Bezy and Sites (1987) conducted a genetic analysis of the genus determined, among other things, that X. h. henshawi and X. h. gracilis differ in allozymes but they are most alike based on phylogeny, indicating that they are the most closely related of the Xantuids. They found that X. h. bolsonae was most closely related to the sympatric X. vigilis extorris and that the morphological similarities to X. henshawi were independently derived. A recent genetic study on the granite night lizard by Lovich (2001) shows that the species is divided into three haploclades with high degrees of sequence divergence. The three habploclades are separated geographically by the San Jacinto and Elsinore fault zones and their associated geophysical features (e.g., canyons and valley floors). Two of the three haploclades occur within the Plan Area and are separated by the San Jacinto fault zone. One haploclade occurs in the Santa Rosa and San Jacinto Mountains, and the other occurs in the Lake Perris region.
Diet and Foraging: Xantusia henshawi henshawi is known to prey on spiders, ants, bees, beetles, true bugs, moths, flies, and other invertebrates (Brattstrom 1952; Stebbins 1954). In addition, they also eat their shed skin (Holland and Goodman 1998) and the female eat the fetal membranes and injest the amniotic fluid (Holland and Goodman 1998). Grisner and Galvan (1996) found that Xantusia henshawi gracilis will eat lizard eggs; however, X. h. hemshawi did not even notice the eggs or recognize their value as a food resource. Zantusia henshawi henshawi forages in the cracks and crevices of their rock outcrop or lie in wait (Lee 1974; Zeiner et al. 1988), however they do not feed in the open (Zeiner et al. 1988).
Daily Activity: Xantusia henshawi hanshawi's common name suggests that it is strictly nocturnal, however it is not (Maultz and Case 1974; Bezy 1988). Holland and Goodman (1998) propose that their cryptic coloration and microhabitat usage of crevices and fissures within rocks probably makes diurnal activity difficult to observe. Lee (1974) conducted an extensive study on the daily activity of Xantusia henshawi henshawi in mid-summer. He found that they were moderately active, nocturnally, on the surface of the boulders. However, these represented a small proportion of the study population and they were mostly adults. Because the night lizards live secret lives under rock caps, fissures, and crevices, both Lee (1974) and Moutz and Case (1974) conducted a controlled laboratory study in which the lizards were kept in constant light and constant darkness respectively. They found that in midsummer the lizards kept a diurnal activity cycle with most activity occurring at dawn and dusk.
Xantusia henshawi henshai becomes active in early to mid-spring and remains active until late summer or early fall (Zeiner et al. 1988).
Reproduction: In the sexually dimorphic, viviparous Xantusia henshawi henshawi, females become sexually mature at approximately 56 mm, which is usually around the third or fourth year, while males are sexually mature at the end of their second year or the beginning of their third year at a snout-vent length of 50 mm (Lee 1975; Zeiner et al. 1988; Holland and Goodman 1998). All reproduction activities take place within the confines of the rock crevices and fissures (Zeiner et al. 1988). Copulation usually occurs in May and June (Zeiner et al. 1988), following which between 1 and 2 eggs are laid (Lee 1973b; Zeiner et al. 1988; Holland and Goodman, 1998). Broods are born between mid-September and mid-October (Lee 1973b; Zeiner et al. 1988; Holland and Goodman 1998). Egg development takes three months (Lee 1973b; Zeiner, et al. 1988).
Survival: There is little information regarding survivorship or longevity in the literature, only one study conducted by Lee (1975) was located. Lee (1975) found that despite poor life table data, the following conclusions could be drawn: If the population is in equilibrium, then annual mortality approximates 28 percent; A large number of adults in the sample indicates that mortality is low; fire and predation do not play a major role in mortality. Population is maintained at a 1:1 sex ratio regardless of age class (Lee 1975).
Dispersal: There is no information regarding dispersal or seasonal movements other than a brief statement by Holland and Goodman (1998) that they may use grasslands or other similar habitat between boulder outcrops, as a movement corridor.
Socio-Spatial Behavior: There is no information in the literature regarding home range size. A number of authors including Heimlich and Heimlich (1947), Lowe (1948), Brattstrom (1952), Zweifel and Lowe (1966), and Lee (1975) all reported direct and indirect evidence that the night lizard engages in aggressive behavior.
Community Relationships: A number of sympatric snakes and some lizards have been noted to eat night lizards in captivity (Lee 1975) and Murray (1955) noted that a granite night lizard was found with part of a night lizard in its mouth. Diurnal birds such as scrub jays, common raven, red-tailed hawk, greater roadrunner, American kestrel and nocturnal birds such as owls, may be potential predators, but they are generally excluded by microhabitat features (Lee 1975). Some rodents such as woodrats may also be potential predators (Lee 1975). A number of reptile species may compete for food resources and possibly cover resources (Lee 1975).
Threats to this species is likely to stem from destruction of occupied rock outcrops with fractures, crevices, and loose caps by development, agriculture, or collecting. Conversion of occupied habitat to agriculture would possibly reduce the population. Damage to fractures by reptile prospectors would permanently ruin necessary habitat features. Lee (1975) proposed that hot fires may increase habitat by creating more fractured rock.
Xantusia henshawi henshawi is restricted to fractured or flaking rock outcrops predominantly in chaparral and chaparral ecotonal areas. The preferred elevational range is between 130 and 1200 m. The night lizard is slow growing and is not very prolific when compared to other sympatric lizards; however, it does not appear to be very susceptible to fire and predation and enjoys a high survivorship.
Bezy, R.L. 1972. Karyotypic variation and evolution of the lizards in the family Xantusiidae. Natur. Hist. Mus. Los Angeles County Contrib. Sci. 227:1-29.
Bezy, R.L. 1988. The natural history of the night lizards, family Xantusiidae. In: DeLisle, H.F., P.R. Brown, B. Kaufman and B.M. McGurty (eds). Proc. Conf. Calif. Herpetol. Spec. Publ. Southwestern Herpetologists Soc.
Bezy, R.L. and J.W. Sites. 1987. A preliminary study of allozyme evolution in the lizard family Xantusiidae. Herpetologica 43:280-292.
Brattstrom, B.H. 1952. The food of the night lizards, genus Xantusia. Copeia 1952:168-172.
Cope, E.D. 1895. The genera of Xantusiidae. Amer. Nat. 29:757-758.
Glaser, H.S. 1970. The distribution of amphibians and reptiles in Riverside County, California. Riverside Mus. Natur. Hist. Ser. (1):1-40.
Grismer, L.L., and G.A. Galvin. 1986. A new night lizard (Xantusia henshawi) from a sandstone habitat in San Diego County, California. Trans. San Diego Soc. Natur. Hist. 21:155-165.
Heimlich, E.M. and M.G. Heimlich. 1947. A case of cannibalism in captive Xantusia vigilis. Herpetologica 3:149-150.
Holland, D.C., and R.H. Goodman. 1998. A guide to the amphibians and reptiles of MCB Camp Pendleton, San Diego County, California. Report submitted to AC/S Environmental Security, Resource Management Division, MCB Camp Pendleton, Contract M00681-94-C-0039. Unpaginated.
Lee, J.C. 1973a. The daily activity cycle of the lizard, Xantusia henshawi. Copeia: 934-940.
Lee, J.C. 1973b. The autecology of the granite night lizard, Xantusia henshawi henshawi Stejneger (Sauria: Xantusiidae). MS Thesis, Sna Diego State University, San Diego, California.
Lee, J.C. 1975. The autcology of Xantusia henshawi (Sauria:Xantusiidae). Trans. San Diego Soc. Natur. Hist. 17:259-278.
Lee, J.C. 1976. Xantusia henshawi. Catalogue of Amer. Amphib. And Rept. 189.1-189.2.
Lovich, R. 2001. Phylogeography of the night lizard Xantusia henshawi in southern California: evolution across fault zones. Herpetologica 57(4): 470-487.
Lowe, C.H. 1948. Territorial behavior in Xantusia vigilis. Herpetologica 4:221-222.
Mautz, W.J., and T.J. Case. 1974. A diurnal activity cycle in the granite night lizard, Xantusia henshawi. Copeia 1974:243-251.
Murray, KF. 1955. Herpetological collections from Baja California. Herpetologica 11(1):33-48.
Stebbins, R.C. 1954. Amphibians and reptiles of western North America. McGraw-Hill Book Co. Inc., New york. 536 pp.
Stebbins, R.C. 1985. A field guide to western reptiles and amphibians. Houghton Mifflin Company, Boston, MA. 336 pp.
Webb, R.G. 1970. Another new night lizard (Xantusia) from Dorango, mexico. Los Angeles County Mus. Contrib. Sci. 194:1-10.
Zeiner, D.C., W.F. Laudenslayer, Jr., and K.E. Mayer. 1988. California's wildlife. Volume I. Amphibians and reptiles. California Statewide Wildlife Habitat Relationships System, California Department of Fish and Game, Sacramento, California.
Zweifel, R.G., and C.H. Lowe. 1966. The ecology of a population of Xantusia vigilis, the desert night lizard. Amer. Mus. Novitates 2247:1-57.
granite spiny lizard (Sceloporus orcutti)
State: None
Federal: None
The granite spiny lizard population is widespread throughout the Plan Area. The granite spiny lizard occurs in a wide variety of habitats but is restricted to granite outcrops and boulder fields. The species is common in most areas of the Plan Area where granite outcrops and boulder fields occur and is well distributed throughout, occurring at all elevation levels. No specific management regimes are needed to maintain adequate habitat for this species, although management of habitat for a wide variety of upland species such as the California gnatcatcher, Stephens' kangaroo rat, forest species, Los Angeles pocket mouse may benefit the granite spiny lizard, where the managed species co-occur with granite outcrops and boulder fields.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area granite outcrops and boulder fields within at least 408,216 acres of chaparral, coastal sage scrub, desert scrub, Riversidean alluvial fan sage scrub, pinyon juniper scrub, montane coniferous forest, and woodlands and forests in large blocks throughout the Plan Area.
Include within the MSHCP Conservation Area at least 12 Core Areas at the Santa Rosa Plateau (8,360 acres), Lake Skinner-Diamond Valley Lake (29,070 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake (50,000 acres), Aqua Tibia Mountains (10,460 acres), San Jacinto Mountains (140,000 acres), Santa Ana Mountains (71,490 acres), and Anza Valley (4,290 acres).
As described below, the granite spiny lizard may be found in almost any habitat where granitic boulders occur. For purposes of this conservation analysis, potential habitat for the granite spiny lizard includes coastal sage scrub, chaparral, desert scrubs, Riversidean alluvial fan scrub, montane coniferous forest, pinyon juniper scrub, and woodlands and forest at all elevation levels within the Plan Area. However, only portions of these habitats which support granitic boulders and slabs will be appropriate. Based on these habitats the Plan Area supports approximately 645,850 acres of potential habitat for the Granite spiny lizard. Table 1 shows the conservation of potential habitat for the Granite spiny lizard. Approximately 408,216 acres (63 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources, including the granite spiny lizard. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
As described below under Data Characterization, 103 of the 166 data points have a precision of "1" or "2." Of these 103 locations, 33 (32 percent) would be within the MSHCP Conservation Area. It was estimated that approximately one-fifth of the MSHCP Plan Area supported suitable granitic rock outcrops. The reserve design conserves approximately the same percentage of rock outcrops. While there are definable locations for focusing conservation efforts, there does not appear to be any key populations that would be essential for conservation of the species. It is likely that wherever rock outcrops exist in substantial number, populations would persist. Because they conduct nearly all activities on rock boulders and outcrops, they are always close to cover.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
GRANITE SPINY LIZARD
| Vegetation Type | MSHCP Plan Area (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area1 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 413,488 | 64,899 | 207,381 | 272,280 | 59,582 | 81,626 | 141,210 |
| Coastal Sage Scrub | 152,686 | 47,161 | 34,555 | 81,716 | 26,241 | 44,729 | 70,970 |
| Desert Scrubs | 9,378 | 3,675 | 1,314 | 4,989 | 44 | 4,345 | 4,389 |
| Montane Coniferous Forest | 29,900 | 17 | 20,485 | 20,502 | 43 | 9,355 | 9,398 |
| Peninsular Juniper Woodland and Scrub | 1,082 | 336 | 274 | 610 | 23 | 450 | 473 |
| Riversidean Alluvial Fan Sage Scrub | 7,149 | 3,171 | 2,063 | 5,234 | 217 | 1,697 | 1,915 |
| Woodlands and Forest | 32,167 | 2,388 | 20,497 | 22,885 | 5,017 | 4,266 | 9,282 |
| TOTAL | 645,850 | 121,647 | 286,569 | 408,216 | 91,167 | 146,468 | 237,637 |
| 1 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. | |||||||
Several large blocks of habitat supporting the granite spiny lizard would be conserved throughout the MSHCP Conservation Area within the following Core Areas: Lake Mathews/Estelle Mountain (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres), Santa Rosa Plateau (Existing Core F; 8,360 acres), Vail Lake/Sage (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Mountains (Existing Core M; 10,460 acres), Santa Ana Mountains (Existing Core B; 71,490 acres), and the San Jacinto Mountains (Remaining bulk of Existing Core K: approximately 140,000 acres). However, most every other Core Area (existing or proposed), including State Parks and National Forests, could also be expected to support granite spiny lizard where rock outcrops are present. Connections between the supporting blocks of habitat are probably not necessary as rock outcrops and accompanying populations are currently isolated by intervening unsuitable habitat (habitat without rock outcrops or boulders) and development. Maintenance of rock outcrop clusters and rows, where they exist within the reserve, will be important toward maintaining the genetic diversity of the population. Granite spiny lizards were found to have a maximum home range of 17 m in diameter and show strong site attachment as adults, both during the year and through a life span. Genetic exchange takes place over the long term. Dense vegetation restricts movement and may form a barrier to expansion or genetic exchange. Nothing is known about genetic relationships between granite spiny lizards within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However, in the absence of data, it is generally thought that it is best to preserve representative populations at the limits of its distribution and range, including longitude, latitude, and elevation. To this end, the Criteria Area contains at least one habitat block at all cardinal compass points and all elevation levels represented within the study. All of these contain, or are expected to contain, the habitat requirements necessary to support healthy granite spiny lizard populations.
Numerous smaller habitat areas would likely be isolated from other habitat by development or high density roadways. These areas include the Jurupa Mountains (Proposed Noncontiguous Habitat Block 2; 1,230 acres), Box Springs Mountain (Existing Noncontiguous Habitat Block A and Constrained Linkage 8; 2,920 acres), Steele Peak/Gavilan Hills/Gavilan Plateau (Proposed Linkage 3; 5,540 acres), Sycamore Canyon Regional Park/March Air Force Base (Existing Core D; 2,510 acres), West Hemet (Proposed Noncontiguous Habitat Block 7; 1,250 acres), and Motte-Rimrock Reserve (Proposed Noncontiguous Habitat Block 4; 1,150 acres) among others. These areas are expected to continue to support granite spiny lizard populations.
Implementation of the MSHCP Plan, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the granite spiny lizard. The current population size is unknown and estimating population densities is labor intensive. Granite spiny lizards are obvious animals which exclusively utilize boulders and rock outcrops.
The MSHCP Plan will conserve large and small Core Areas in the habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, are unlikely to be at higher risk of extirpation resulting from catastrophic events or demographic or genetic stochasticity due to the species cover utilization, alertness, and known site fidelity and dispersal requirements.
In summary, conservation for the granite spiny lizard will be achieved by the inclusion of at least 408,216 acres of suitable Conserved Habitat within 12 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size of the granite spiny lizard is unknown, but the general distribution is, and a relatively sizable database is present within the UCR database. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
Approximately 237,637 acres (37 percent)of potential habitat for the granite spiny lizard would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Seventy (68 percent) of the 103 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However of these, 13 (19 percent) are mapped within existing agriculture and 18 (26 percent) are located in developed or disturbed habitat coverages. The remaining 39 (56 percent) are in natural habitats.
The MSHCP data base includes 166 records for the granite spiny lizard between 1999 and 1907. Of the 166 records, 75 (45 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 28 (17 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 63 (38 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). A large number of the precision code "1" or "2" records are relatively recent, with 78 (76 percent) since 1990 and 25 (24 percent) pre-dating 1990 or with no associated date. Abundant information exists in the literature, for the granite spiny lizard. However, there is no information available regarding survivorship and little information regarding dispersal and socio-spatial behavior. This level of detail is probably sufficient for a species reliant on an obvious habitat feature (rock outcrops in this case).
The records are scattered throughout the Plan Area with only a few clusters. While there are no areas that could be defined as "core" areas, clusters occur in the Santa Rosa Plateau area, Canyon Lake area, Sage area, Winchester area, Gavilan Hills area, and Riverside area. Other abundant suitable habitat exists within the National Forests. It is estimated that approximately one-fifth of the MSHCP Plan Area supports granitic outcrops.
Klauber (1939) observed that Sceloporus orcuttii is often present under granite flakes on boulders, being the most abundant lizard on rock outcrops in Riverside County. Zeiner et al. (1988) write that it occurs in areas dominated by massive rock formations, spends most of its time foraging or basking on rocks and seeking shelter in rock crevices and under rocks (Mayhew 1963; Zeiner et al. 1988). Shaw (1950) and Weintraub (1981) observed it to occur on granite outcroppings and on palm trees.
Regardless, boulders are the key character (Mayhew 1963) within a variety of chaparral and forest habitats (Zeiner et al. 1988). Mayhew (1963a) and Holland and Goodman (1998) state that it is found in chaparral, coastal sage scrub, and riparian areas, but closely tied to fractured granodiorite rock outcrops. Mayhew (1963b) added yellow pine forest and pinyon-juniper woodlands to the known habitats. Stebbins (1985) went into greater detail describing the specific regions where certain habitats were used. Essentially, Sceloporus orcuttii frequents granite outcrops in areas of oak and chaparral, ranging into yellow pine habitat on the coastal side of the mountains, while on the desert side of the mountains, it is found in rocky canyons and on the rocky upper portions of alluvial fans, where there is sufficient moisture for the growth of chaparral, palms, or mesquite. In Baja California, Mexico it is found in pinon-juniper woodlands, and subtropical thornforest.
Generally speaking, Sceloporus orcuttii ranges from southern California, through northern and southern Baja California, Mexico. More precisely, it occurs on the lower slopes of the Peninsular Ranges from approximately the northern side of San Gorgonio Pass (Stebbins 1985; Zeiner et al. 1988). Elevational range is from sea level to 2130 m (Stebbins 1985), though it usually ranges only to 1800 m on the western side of the mountains (Mayhew 1963b; Weintraub 1981; Stebbins 1985).
Research collections were made of Sceloporus orcuttii by Mayhew (1963) on typical habitat at the University of California at Riverside Campus (UCR), Box Springs Mountains just east of UCR, granite outcrops between 2-9 miles south of UCR, Mount Rubidoux in the City of Riverside, and in the San Jacinto Mountains. Additional locations as reported by UCR and Weintraub (1980) include Santa Ana Mountains, Arlington, Mockingbird Canyon, Reche Canyon, Moreno, Val Verde, Woodcrest, Gavilan, Temescal, Perris, Elsinore, Lake Perris State Park, Domenigoni Valley, Vail Lake area Potrero Valley, Cactus Valley, Crown Valley, Harford Springs area, Motte Reserve, and the Santa Rosa Plateau. It appears that the species is distributed throughout the Plan Area where fractured rock outcrops and some native shrubby vegetation is present, however the populations appear to be concentrated around the foothills surrounding the San Jacinto Mountains as opposed to the Santa Ana Mountains.
Key population areas occur at locations where fractured rock and scrub, chaparral, or woodland/ forest situations occur. The primary key areas are probably situated around the San Jacinto Mountains, in the vicinity of Banning and Beaumont, the Gavilan Hills, and south toward Pauba Valley, Aguanga, and Anza. Suitable habitat within these areas up to 1800 m in elevation should be considered key.
Genetics: Sceloporus orcuttii was initially described by Stejeger in 1893, based on specimens captured by Charles Orcutt in 1890. Mocquard (1899) described the synonym, Sceloporus digueti based on a specimen captured by Leon Diguet. These were later combined. A number of authors have written on the taxonomy of the species based on morphology and distribution. A comprehensive study describing the genetic relationships between members of the genus Sceloporus was conducted by Wiens and Reeder (1997) using DNA sequences from mitochondrial and ribosomal RNA genes and morphology. Based on DNA sequencing, S. orcutii is most closely related to S. licki and both stemmed from a common ancestor of S. hunsakeri. However, based on morphological data, S. hunsakeri and S. licki stemmed from a common ancestor of S. orcuttii. Based on DNA sequencing, S. orcuttii is four steps removed from S. occidentalis, five steps removed from S. graciosus, and three steps removed from S. magister, its three sympatric relatives.
Diet and Foraging: The primarily insectivorous Sceloporus orcuttii, forages on ants beetles, bees, butterfly larvae, grasshoppers, sowbugs, and cicadas, however it has also been observed to eat leaf and flower buds and fleshy fruits (Mayhew 1963b; Stebbins 1985; Zeiner et al. 1988; Holland and Goodman 1998).
It is known to cannibalize smaller individuals (Stebbins 1954; Mayhew 1963b). Sceloporus orcuttii primarily forage on the rock outcrops (Zeiner et al. 1988).
Daily Activity: Sceloporus orcuttii is diurnal (Zeiner et al 1988). It basks on the rock outcrops all day during mild weather and normally restricts basking activity to the early and late portions of the day when temperatures are high (Zeiner et al. 1988; Holland and Goodman 1998). S. orcuttii is normally active from between March through September, but if conditions are warm, it may be periodically active through January (Zeiner et al. 1988; Holland and Goodman 1998). In Riverside, they may emerge from hibernation in January, but are not normally numerous until March (Mayhew 1963b), going into hibernation by November.
Mayhew's (1963b) study of the temperature preferences of S. orcuttii gleaned some interesting results. He found that the times of daily emergence varies with age and weather conditions; younger animals were active earlier than adults and stayed active longer than adults and all individuals retreated when in high winds and cloudy conditions. Sceloporus orcuttii was active within the 14.4 C to 37.9 C thermal range. Mayhew also found that they enter hibernation at varying times depending on location and weather. He found that once they enter into hibernation, they are roused by some other trigger than temperature or weather mechanism.
Reproduction: In Sceloporus orcuttii, the females become sexually mature at about three years of age or at a minimum snout-vent length 85 mm, while the male becomes sexually mature at about 90 mm snout-vent length (Mayhew 1963c; Holland and Goodman 1998). Copulation usually occurs in March or April, following which between 8 and 15 eggs are laid, usually between the months of May to early June (Zeiner et al. 1988) or July and August (Mayhew 1963c). Only one clutch is laid per year (Mayhew 1963c). The young hatch between July and September (Holland and Goodman 1998).
Survival: There is no information regarding survivorship or longevity in the literature, the only source being a few sentences from Mayhew (1963b). Mayhew states that during his studies between 1958 and 1961, there was no measurable difference in relative abundance during a single year until that year's cohort hatched. He attributed the lack of change, during a year, to relatively long life expectancy for Sceloporus orcuttii. He found that while the maximum life expectancy is unknown, males have lived at least 6 years and females have lived at least 5 years in the field.
Dispersal: The only literature source regarding Sceloporus orcuttii movements is from Mayhew (1963b). His paper also reports the results of three other researchers, Duare Munro, Daniel Goodcase, and Gail Nicolls. This section synopsizes that paper. Daily movements were found to vary extensively, ranging from minor 1 m ectothermic adjustments to 44 m travels across a number of outcrops and a steep ravine. These movements may be made at once, or over a period of hours, and the number of stops per movement is unrelated to sex or distance. Within a year, Sceloporus orcuttii apparently moves less during the early spring months as opposed to summer and fall. Goodcase found that during his spring study, males moved an average maximum distance of 8 m while females moved an average of 2.5 m. However, Munro found that during the summer and fall months, males, females, juvenile males, and juvenile females moved an average maximum distance of 29.5, 5.5, 3, and 1.5 m respectively. Mayhews study confirmed Munros findings. Mayhew found that some animals were always found at the same location, while others were never seen at the same location twice. Mayhew found that the distances traveled between years did not differ significantly from the distances traveled during a single year. Goodcase found that the largest home range was 17 m in diameter, however these territories were not defended. Individuals usually have a center of activity, within the home range, that they return to after foraging. Adults are adept at homing (experiments have shown them to home at least 128 m), while juveniles are not. This may be a result of strong site attachment in adults and lack of site attachment in juveniles.
Socio-Spatial Behavior: Zeiner et al. (1988) states that males are territorial, however Mayhew (1963b) indicates that none of the studies described by him has ever witnessed a territory defensive event. Though not social, animals are not solitary, and many can occur together in the same area within suitable habitat. Sceloporus orcutti may overwinter communally, with the younger age classes in the least desirable, or more exposed crevices (Weintraub 1968; Holland and Goodman 1998).
Community Relationships: The only known predation on Sceloporus orcuttii, within the literature, is known from cannibalism (Mayhew 1963b), however predation by greater roadrunner (pers obs.) has been observed. Other species which may predate on Sceloporus orcuttii may include woodrats, ringtail cats, black-tailed weasel, some birds, larger lizards, and various snakes including rattlesnakes. However, Mayhew (1963b) states that on a couple of occasions granite spiny lizards were observed within a couple of feet from red-diamond rattlesnake and neither had interest in the other.
Threats to this species is likely to stem from destruction of occupied rock outcrops with fractures, crevices, and loose caps by development, agriculture, or collecting. Conversion of occupied habitat to agriculture would likely reduce the population significantly if not completely. Damage to fractures by reptile prospectors would permanently ruin necessary habitat features. Fire suppression may cause habitat conversion of more open habitats into denser habitats which are traversed with much less frequency. Though untested, uncontrolled, hot fires may increase habitat by creating more fractured rock and opening up dense chaparral.
Sceloporus orcutti is tied to rock outcrops (primarily fractured and flaking outcrops) in a variety of habitats. The preferred elevational range is up to 1800 m. They have relatively small home ranges, but can move relatively great distances in a short period of time. Their movements between rock outcrops appear to be restricted by dense vegetation (Mayhew 1963b). Adults appear to be very site tenacious, while juveniles are not.
Holland, D.C., and R.H. Goodman. 1998. A guide to the amphibians and reptiles of MCB Camp Pendleton, San Diego County, California. Report submitted to AC/S Environmental Security, Resource Management Division, MCB Camp Pendleton, Contract M00681-94-C-0039. Unpaginated.
Klauber, L.M. 1939. Studies of reptile life in the arid southwest. Bull. Zool. Soc. San Diego, 14:1-100.
Mayhew, W.W. 1963a. Temperature preferences of Sceloporus orcuttii. Herpetologica 18(4):217-233.
_________ 1963b. Biology of the granite spiny lizard, Sceloporus orcutti. The American Midland Naturalist 69(2):310-327.
_________ 1963c. Reproduction in the granite spiny lizard, Sceloporus orcuttii. Copeia 1963(1):144-152.
Shaw, C.E. 1950. The lizards of San Diego County with descriptions and key. Bull. Zool. Zoc. San Diego. 25:1-100.
Stebbins, R. C. 1985. A field guide to western reptiles and amphibians. Houghton Mifflin Company, Boston, MA. 336 pp.
Weintraub, J.D. 1968. Winter behavior of the granite spiny lizard, Sceloporus orcuttii Stejneger. Copeia 1968(4):
_________ 1980. Sceloporus orcutti. Cat. Am. Amphibians and Reptiles 265.
Weins, J.J., and T.D. Reeder. 1997. Phylogeny of the spiny lizards (Sceloporus) based on molecular and morphological evidence. Herpetological Monographs. 11:1-101.
Zeiner, D.C., W.F. Laudenslayer, Jr., and K.E. Mayer. 1988. California's wildlife. Volume I. Amphibians and reptiles. California Statewide Wildlife Habitat Relationships System, California Department of Fish and Game, Sacramento, California.
northern red-diamond rattlesnake (Crotalus ruber ruber)
State: Species of Special Concern
Federal: Species of Special Concern
The northern red-diamond rattlesnake is widely distributed throughout the Plan Area. Data collected for this species shows a patchy distribution within the Plan Area without clearly defined Core Areas. The red-diamond rattlesnake is often found in areas with dense vegetation especially chaparral and sage scrub up to 1,520 meters in elevation. There are no definable Core Areas for this species. It is anticipated that this species will respond to a landscape level of management with site-specific requirements (e.g., hibernacula).
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 338,672 acres of chaparral and sage scrub within the Plan Area below 1,520 meters. Acreage conserved include large core blocks within the MSHCP Conservation Area representing a wide range of elevations.
Include within the MSHCP Conservation Area at least 10 Core Areas at the Santa Ana Mountains (71,490 acres), Agua Tibia Mountains (10,460 acres), San Jacinto Mountains (140,000 acres), Lake Skinner-Diamond Valley Lake (29,070 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake (50,000 acres), and Anza Valley (4,290 acres).
Include within the MSHCP Conservation Area Linkages between Core Areas (including hibernacula that are a limiting habitat feature for this species). Connections between the Core Areas will be facilitated by upland and riparian connections from Estelle Mountain to Wildomar, Gavilan Hills, San Jacinto River, Kolb Creek/Arroyo Seco, Temecula Creek, Tucalota Creek, Wilson Creek, Tule Creek, and San Gorgonio Wash.
While the red-diamond rattlesnake may utilize a wide range of habitat types, it is most commonly associated with undisturbed old growth chaparral and coastal sage scrub (Jennings and Hayes 1994, Fisher and Case 1997). For the purpose of this conservation analysis, we have considered the primary habitats for this species to include chaparral, desert scrub, Riversidean alluvial fan sage scrub, and coastal sage scrub up to 1,520 m. in elevation. While the northern red-diamond rattlesnake is also found in oak woodlands, and coniferous forests, these are considered secondary habitat types for this species. Based on these habitats, the Plan Area supports approximately 553,451 acres of potential habitat for the northern red-diamond rattlesnake. Table 1 shows the conservation of potential habitat for the northern red-diamond rattlesnake. Approximately 338,672 acres (62 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. These lands will be managed for wildlife resources including the northern red-diamond rattlesnake. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
NORTHERN RED-DIAMOND RATTLESNAKE
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 384,686 | 64,573 | 182,527 | 247,100 | 59,480 | 78,104 | 137,584 |
| Coastal Sage Scrub | 152,375 | 47,125 | 34,361 | 81,486 | 26,227 | 44,660 | 70,887 |
| Desert Scrubs | 9,252 | 3,674 | 1,190 | 4,864 | 43 | 4,343 | 4,386 |
| Riversidean Alluvial Fan Sage Scrub | 7,135 | 3,170 | 2,052 | 5,222 | 217 | 1,695 | 1,912 |
| TOTAL | 553,451 | 118,546 | 220,134 | 338,672 | 85,969 | 128,804 | 214,769 |
| 1 Total acres only includes habitats below 1,520 m. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
As described below under Data Characterization, 52 of the 91 data points have a precision of "1" or "2." Of these 52 locations, 20 (39 percent) would be within the MSHCP Conservation Area. Conservation of this species should be considered from a landscape perspective with minor monitoring because the species is found throughout the Plan Area and may occur in a variety of habitats. While there are definable locations for focusing conservation efforts, there does not appear to be any specific key populations that would be essential for conservation of the species.
Several large blocks of habitat supporting the northern red-diamond rattlesnake would be conserved, including areas within Lake Mathews/Estelle Mountain (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres), Santa Rosa Plateau (Existing Core F; 8,360 acres), Vail Lake/Sage (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley Lake (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,430 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Wilderness (Existing Core M; 10,460 acres), Santa Ana Mountains (Existing Core B; 71,490 acres), and San Jacinto Mountains (Existing Core K; 140,000 acres). It is anticipated that many of the habitat linkages between large blocks will provide adequate linkages for the rattlesnakes. Although minimum dispersal distance is not reported for northern red-diamond rattlesnakes, Fitch and Shirer (1971) found that they traveled between 45 and 150 m per day. Most of the linkages could accommodate this movement and would likely support home ranges to facilitate multi-generational movement through linkage areas. However, movement across large roads and freeways will be hampered in areas without large vehicular overpasses. It is unlikely that reptiles, including rattlesnakes, will utilize long and narrow undercrossings to emigrate to new habitat and movement across roads will likely result in high mortality rates.
Movement across large roads and freeways will be hindered in areas without large vehicular overpasses. It is unlikely that reptiles, including the San Diego horned lizard, will utilize long and narrow undercrossings to occupy new habitat and over-road movement of reptiles will likely result in mortality. Some successful movement of reptiles is expected under bridges greater than 50 feet in length.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the red-diamond rattlesnake within the MSHCP Conservation Area. Ensuring that the species remains viable in the MSHCP Plan Area will require a systematic monitoring program as described above.
The MSHCP will conserve large Core Areas and habitat linkages that are suitable for occupation by the red-diamond rattlesnake in the large habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, may be at higher risk of extirpation either rapidly as a result of some catastrophic event, or over the longer term as a result of demographic or genetic stochasticity (e.g., random birth and death rates, inbreeding depression, genetic drift) or resulting from the indirect effects of proximate development. In regions proximate to development, rattlesnake populations may be affected by predation from domestic pets, harassment and mortality by adjacent home owners, and vehicle-caused mortality.
In summary, conservation for the northern red-diamond rattlesnake will be achieved by the inclusion of at least 338,672 acres of suitable Conserved Habitat within 12 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size of the red-diamond rattlesnake is unknown, but the general distribution is, and a relatively sizable database is present within the UCR database. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
The Incidental Take of northern red-diamond rattlesnake is difficult to quantify due to our limited knowledge of the species distribution within the Plan Area and the fact that losses may be masked by fluctuations in abundance and distribution during the life of the permit. However, the maximum level of Take of the northern red-diamond rattlesnake can be anticipated by the loss of the number of acres of habitat that will become unsuitable for this species. Approximately 214,769 acres (39 percent) of potential habitat for the northern red-diamond rattlesnake would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Thirty-two (62 percent) of the 52 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However, of these, 6 (19 percent) are mapped within existing agricultural areas and 9 (28 percent) are mapped in residential/urban/exotic/pond areas.
The MSHCP data base includes 91 records for the northern red-diamond rattlesnake between 1999 and 1919. Of the 91 records, 32 (35 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 20 (22 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 39 (43percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). A large number of the precision code "1" or "2" records are relatively recent, with 20 (39 percent) since 1990 and 32 (61 percent) pre-dating 1990 or with no associated date. The reason for the lack of more recent locations is likely due to a anecdotal nature of detecting normally shy rattlesnakes and historical data base dating to the early 1920's. As made apparent in the following discussion, little specific information exists for the northern red-diamond rattlesnake in particular, however abundant information exists for western rattlesnakes in general. In particular, specific information is needed regarding basic life history parameters, cohort survivorship data, maturation rates, growth rates, longevity, dispersal, and socio-spatial behavior.
The records are scattered from the Plan Area with few records from the higher elevations of the Santa Ana Mountains and San Jacinto Mountains. Because the records are generally evenly distributed throughout the Plan Area, there are no definable "key" or "core" populations. However, there are a few lightly clustered areas within the Plan Area. These include the Highgrove area, Meadowbrook area, and Lake Skinner area.
From an ecological standpoint, the rattlesnake has a wide tolerance for varying environments. For example throughout the range of C. r. ruber, rainfall varies from 3 to 30 inches per annum. In San Diego County it can be found from the desert, through dense chaparral in the foothills (it avoids the mountains above around 4,000 feet), to warm inland mesas and valleys, all the way to the cool ocean shore. Although C. r. ruber is recorded from a number of vegetation types, it is most commonly associated with heavy brush with large rocks or boulders (Klauber, 1972). Dense chaparral in the foothills, cactus or boulder associated coastal sage scrub (Stebbins, 1954, 1985; Fitch, 1970), and desert slope scrub associations are known to carry populations of C. r. ruber, however, chamise and red shank associations may offer better structural habitat for refuges and food resources for this species than other habitats (Jennings and Hayes, 1994). Prey density likely affects the population dynamics of C. r. ruber, however, availability of suitable dens for both hibernation and gravid females may be a more limiting factor (Keenlyne, 1972).
The known range of C. r. ruber extends from Pioneertown and Morongo Valley in San Bernardino County southward on both coastal and desert sides of the Peninsular Ranges and the Santa Anna Mountains, to Loreto, Baja California (Peguegnat, 1951, Stebbins, 1985). The elevation range of the species is from near sea level to 1,520 meters (m) (Palomar Mountain), though it is most frequently encountered below 1,200 m (Klauber, 1972). Rattlesnakes inhabiting high altitudes are characteristically smaller than lowland forms (Klauber, 1971).
C. r. ruber is known to occur throughout western Riverside County. This species has been observed throughout western Riverside County with the exception of the higher elevations of San Jacinto Mountains. Other localities include Domenigoni Valley, Potrero Valley, and Motte Reserve.
Sage scrub and chaparral habitats with boulder and rock outcrop microhabitats available throughout Western Riverside County.
Genetics: Various research has been conducted to determine the relationship between C. r. ruber, C. lucasensis, C. atrox, and C. exsul. The similarities in lepidosis, pattern and hemipenes serve as evidence of the close relationship between C. ruber and C. lucasensis as derived from C. atrox (Klauber, 1949).
Murphey, et al. (1995) studied the allozyme and morphological uniformity as well as mtDNA sequence among red diamond rattlesnakes, C. ruber and C. exsul. The results barely differentiated the taxa. Among the sequence data, only one nucleotide difference was recorded, however, this amount of variation occurs within other taxa as well (Murphey, et al. 1995). "When considered alone, the single difference observed among C. exsul and C. ruber is seemingly insufficient to justify recognition of these two species, even though (i) the change can be considered conservative because of its location in the first position of the codon and codes for a different amino acid, and (ii) the derived condition may prove to define C. exsul once additional specimens are sequenced" (Murphey, et al. 1995). The allozime data did not reveal any markers unambiguously segregating the two taxa. Furthermore, the two species were not differentiated by the morphological analysis of the peninsular populations of C. exsul. No single character or suite of characters was found to warrant differentiation of the southern and northern subspecies C. e. lucasensis Van Denburgh, 1920 and C. e. ruber (Murphey, et al., 1995). The data indicates a continuous distribution of peninsular red diamond rattlesnakes with apparently no disruption in gene flow. Hence, gene flow should be occurring throughout the peninsula, reducing any possibility of discrete evolutionary assemblages (Murphey, et al., 1995). In addition, Klauber (1949) found evidence of an unbroken cline of C. r. ruber extending from the Santa Ana Mountains of southern California to Cape San Lucas at the southern tip of Baja California.
Diet and Foraging: Principal food resources for adult C. r. ruber includes small mammals such as mice (Heteromyidae; Muridae), rats (Heteromyidae; Muridae), gophers (Geomyidae), white-tailed antelope ground squirrels (Ammospermophilus leucurus), California ground squirrels (Spermophilus beecheyi), chipmunks (Sciuridae), rabbits (Sylvilagus spp.) and tree squirrels (Sciuridae) (Tevis, 1943, Klauber, 1971, 1972). Western whiptails (Cnemidophorus tigris multiscutatus) are a major food source of C. r. ruber juveniles. Many other types of prey are taken opportunistically depending on the local environment such as frogs, toads, lizards, birds and other snakes. Klauber (1972) also reported the remains of a young skunk found in the digestive tract of a rattlesnake.
Rattlesnakes often secure their prey waiting beside heavily traveled game trails and striking as creatures pass by. When a rattlesnake strikes, it rarely retains hold of the creature, allowing the venom to take effect. It then follows the animal by scent, then devours the creature whole, after it has succumbed to the poison. The use of venom allows the snake to avoid injury by holding the struggling creature and also aids in digestion once the prey is swallowed. Prey sizes vary depending on opportunity and size of the hunting snake. Prey may range from 5 percent to over 100 percent of the snakes own body weight; studies have shown that the average is about 40 percent (Klauber, 1971).
Daily Activity: During the course of a rattlesnake's daily activity, the sense of smell is probably the most acute and useful. The impact of odors is carried to the brain via the tongue picking up particles of gaseous, liquid, or minute solid particles from the air and conveying them to two pits, known as Jacobson's organs, in the roof of the mouth whence nerves carry the effect to the brain for analysis (Klauber, 1971). An acute sense of ground vibrations replaces the sense of hearing and the sense of sight is moderately good, but has relatively narrow spatial limitations (Klauber, 1971). The facial pit permits the snake to sense the presence and direction of an object having a slightly higher temperature than that of its surroundings. The vision of each eye is largely independent, binocular vision only occurring within a narrow range. In addition, the vertical pupil improves night vision. Like all snakes, rattlesnakes have no external ear openings, leaving them effectively deaf to airborne sounds.
Fitch and Shirer (1971) observed average daily movements of radio telemetered C. r. ruber of 45 meters, but on 50 percent of the days there was no movement at all. During 10 percent of the tracking time travel distances greater than 150 meters were recorded. Researchers identify this species as one of the most docile rattlesnakes (Gillingham, 1987). Klauber (1972) reports that if the taxon is not roughly treated, it can often be caught without its making any attempt to bite, or even to sound the rattle.
Rattlesnakes can climb and also are good swimmers. Not only do rattlesnakes cross lakes or streams but they are not infrequently found at sea, distant as much as 20 miles from land, particularly in the relatively warm waters of the Gulf of Mexico and off the South Atlantic states (Klauber, 1971). In this way they have colonized islands. The acts of climbing and swimming in rattlesnakes have been well documented in the literature (Klauber, 1972).
C. r. ruber is known to hibernate gregariously, though the reason for this behavior is unknown (Fitch, 1970, Gillingham 1987, Seidel and Ford, 1987). Census data for 16 years collected in San Diego County (Klauber, 1939) suggest that C. r. ruber can be active year around, but most visible during peak mating activity periods between April and May. May is the most active month for rattlers in the southwestern United States.
Reproduction: The life history of C. r. ruber is relatively unknown. Dates of mating and birth are dependent on local climatic conditions, although it is typically annual with mating occurring in the spring and birth in the autumn. In colder climates, there is a biennial reproductive cycle because of the shortened activity season. Wright and Wright (1957) reported that live born young are carried by the female for approximately 140-150 days; however, Klauber (1971) indicated that the length of gestation for the annual cycle is probably four months, suggesting that this duration is speculative because females have a mechanism for sperm storage, producing an irregularity between dates of mating and birth. Mating may occur in the off-season and with sperm-storage, it is possible for two broods to be produced from a single mating or a single brood from multiple matings. Gravid (pregnant) females are gregarious, possibly due to greater protection offered by a group when females are slow and non-mobile (Fitch, 1970).
Generally, rattlesnakes are oviparous and females lay their first clutch at the age of three years. Young are retained in the body of the mother until developed and tissue in thin-walled, ready-to-hatch eggs from which they break out immediately. A temporary specialized tooth (egg-tooth) is employed by the juveniles to slit the thin sac (Klauber, 1971). Once born, the young fend for themselves, receiving no protective interest from the mother. The number of young per brood is highly variable, being dependent on the species of snake and the size of the female.
Male rattlesnakes have been documented to participate in a combat dance which is presumably a sexual exhibition. Typically, two male rattlers rear up and attempt to press each other to the ground with the anterior portions of their bodies. The ritual may last over 15 minutes, depending on the success of one snake over the other. The ritual may be repeated on several successive days and will occur with or without the presence of a female (Klauber, 1971).
Survival: Like other snakes, this taxon's survival is dependant on external temperature effects such as the substrate, air and sun's radiation to secure a favorable body temperature for the requirements of daily activity. A temperature-equalizing function may be derived from the posterior portion of the rattlesnake's major lung. In the Crotalidae there is but one functional lung that has become so enlarged as to extend over about three fourths of the snake's body. It is comprised of three parts, a tracheal section, a bronchial section, and the posterior, nonvascularized, air-storage sac which functions simply to store air (Klauber, 1971). This air-bladder aids the snake's buoyancy while in water, provides extra air supply while the snake is swallowing food and accentuates hissing (Klauber, 1971).
Aggressive behavior is seldom employed unless the animal is annoyed or injured. Once their privacy is encroached upon, defensive mechanisms include procrypsis, fleeing, defensive posture and striking. The defensive posture is highly effective in dissuading potential threats. It involves the snake raising the anterior half of the body up in a loose 'S' shape, the posterior half of the body remaining coiled as a base from which to spring and strike if necessary. The snake faces the enemy, protruding and retracting its tongue and alternately raising it up and down with the tips spread far apart, while usually rattling the tail vigorously.
Many mythical theories have been applied to the purpose of the snake's rattle. However, the theory most consistent with its use is that of a survival mechanism, a warning to creatures that might injure the snake. Although rattlesnakes typically sound the rattle when threatened, it is important to note that they are quite capable of biting without sounding the rattle at all. According to Klauber (1971), rattlesnakes posses some limited (and likely involuntary) ability of color modification following temperature changes. As temperature increases, the resulting change is a lightning of the color; a consequence of the contraction of the melanophores in the skin with a rising temperature. This also aids in the reflection of unneeded heat as temperature increases; and conversely, allows greater absorption with a darker shade before temperatures increase.
Dispersal: No information is available.
Socio-Spatial Behavior: No information is available.
Community Relationships: When hibernating in temperate or cooler environs, rattlesnakes are typically gregarious in nature. Usually, a den is used by the snakes of the contiguous area. Once found to be safe, successive generations of rattlers follow elders into the same refuge that experience has proved secure and adequate (Klauber, 1971). Topography and climate regulate the number of rattlers sharing a den. Where adequate sites are plentiful, the number of individuals in a den will generally be less, and conversely, the number will be large if dens are sparse. However, Klauber (1972) indicates that when good sites are close together, the gregarious nature of the snakes will lead to the selection of particular sites so that the concentrations are fairly large.
In the more southern portion of its range, where the hibernation season is relatively short, refuge selection becomes more a choice of the individual than the group (Klauber, 1972). In southern California's mild climate, dens are impromptu refuges, such as rock crevices, mammal dens or piles of leaves. Often, rattlers will take advantage of warm spells during the winter, leaving their refuges for a few hours to sun themselves.
A significant portion of the historically prime habitat of C. r. ruber has been developed over the last 25 years. Particularly significant has been the rate of development in southwestern Riverside County during the 70's and 80's. Increasing use of steeper, rock slopes for drip agriculture, such as avocado orchards, has significantly intruded into the habitat C. r. ruber historically used. Up to 20 percent loss of suitable habitat may have resulted from this type of development (Jennings and Hayes, 1994). Development in areas of suitable habitat, in particular, those areas of high brush content in association with exposed rock or boulders (Jennings and Hayes, 1994).
Wild and domestic animals that have been found to prey on rattlesnakes for food include birds of prey (e.g., eagles and hawks, especially red-tailed hawks), badgers, coyotes, cats, foxes, dogs, certain snakes (e.g., kingsnakes, racers, black snakes and indigo snakes) and hogs. Ungulates such as deer, horses, antelope, sheep, goats, and cattle have a propensity for killing rattlesnakes by stomping them to death. Although many animals may prey upon rattlesnakes, the automobile has proved to be the most destructive to the animal.
Significant threats to the species result from habitat fragmentation and isolation and the associated indirect effects of decreased chances for generational genetic exchange, and direct effects of vehicular interactions. Furthermore, the more potential interactions the snakes have with humans, only increases the chance that they will be killed as nuisance animals. Isolation of remaining habitat and proximity of isolated habitat islands to existing and new urban and suburban residential development will only increase rattlesnake mortality.
Nothing is known about maturation rates, growth rates, or longevity of this species. Because extensive capture, marking and recapture studies have not been conducted for this dangerous species, life span estimates of individuals in the wild have not been determined with any accuracy. It is presumed that they occasionally attain an age of 12 to 14 years (Klauber, 1971). In captivity, several species of rattlesnakes have been kept alive for 18 to 20 years at the San Diego Zoo (Klauber, 1971). Bowler (1977) reported a captive C. r. ruber living 14 years. Rattlesnakes have been documented to survive for a year or more without food in captivity, however, they cannot survive this long without water.
Bowler, J. K. 1977. Longevity of reptiles and amphibians in North American collections. Society for the Study of Amphibians and Reptiles, Miscellaneous Publications, Herpetological Circular (6):1-32.
Fisher, R.N., and T.J. Case. 1997. A field guide to the reptiles and amphibians of coastal southern California. Self Published with support from USGS/BRD.
Fitch, H. S., and H. W. Shirer. 1971. A radiotelemetry study of spatial relationships in some common snakes. Copeia 1971:118-128.
Fitch, H. S. 1970. Reproductive cycles in lizards and snakes. Univer. Kansas Mus. Nat. Hist. Misc. Publ. No. 52:1-247.
Gillingham, J. C. 1987. Social behavior. Pages 184-209 in R. A. Seidel, J. T. Collins, and S. S. Novac, eds., Snakes: ecology and evolutionary biology. MacMillan Publishing Company, New York, New York.
Jennings, M. R., and M. P. Hayes. 1994. Amphibian and reptile Species of Special Concern in California. Final report submitted to California Department of Fish and Game, Inland Fisheries Division, Rancho Cordova, California, under Contract 8023.
Keenlyne, K. D. 1972. Sexual differences in feeding habits of Crotalus horridus horridus. J. Herpet. 6:234-237.
Klauber, L. M. 1939. Studies of reptiles life in the arid southwest. Part I, Night collecting on the desert with ecological statistics; Part II, Speculations on protective coloration and protective reflectivity; Part III, Notes on some lizards of the southwestern United States. Bulletin of the Zoological Society of San Diego (14):1-100.
Klauber, L.M. 1949. The relationship of crotalus ruber and crotalus lucasensis. Transactions of the San Diego Society of Natural History. Vol XI, No 5, pp. 57-60. January 31, 1949.
Klauber, L.M. 1971. Classification, Distribution, and Biology of the Venomous Snakes of Northern Mexico, the United States, and Canada: Crotalus and Sistrurus. In (Ch 26): Bucherl W., and E.E. Buckley. 1971. Venomous Animals and Their Venoms. Vol 2, Venomous Vertebrates. Academic Press. New York-London.
Klauber, L. M. 1972. Rattlesnakes: Their habits, life histories, and influence on mankind. Second edition. University of California Press, Berkeley, Los Angeles, London.
Murphey, R.W., V. Kovac, O. Haddrath, G.S. Allen, A. Fishbein, and N.E. Mandrak. 1995. MtDNA sequence, allozyme, and morphological uniformity among red diamond rattlesnakes, Crotalus ruber and Crotalus exsul. Canadian J. Of Zool. V. 73, N.2, 1995:270-281.
Peguegnat, W. E. 1951. The biota of the Santa Ana Mountains. Journal of Entomology and Zoology (Pomona) 42(3/4):1-84.
Seidel, R. A., and N. B. Ford. 1987. Reproductive ecology. Pages 210-252 in R. A. Seidel, J. T. Collins, and S. S. Novac, eds., Snakes: ecology and evolutionary biology. MacMillan Publishing Company, New York, New York.
Stebbins, R. C. 1954. Amphibians and reptiles of western North America. McGraw Hill Book Company, New York, New York.
Stebbins, R. C. 1985. A field guide to western reptiles and amphibians. McGraw Hill Book Company, New York, New York.
Tevis, L. T. 1943. Field notes on a red rattlesnake in lower California. Copeia 1943:242-245.
Van Denburgh, J. 1920. Description of a new species of rattlesnake (Crotalus lucasensis) from lower California. Proc. Calif. Acad. Sci. Ser. 4, 10:29-30.
Wright, A. H., and A. A. Wright. 1957. Handbook of snakes in the United States and Canada. Comstock Publishing Associates, Ithaca, New York.
San Diego banded gecko (Coleonyx variegatus abbottii)
State: Species of special concern
Federal: None
The San Diego banded gecko population is patchily but widely distributed throughout the Riverside Lowlands and San Jacinto Foothills Bioregions. The San Diego banded gecko occurs in a wide variety of sage scrub and chaparral habitats, where suitable cover exists associated with granitic outcrops and boulder fields where there is also ground debris (i.e., yucca stalks). There are no definable key or core populations for this species within the Plan Area. Because it requires scattered to extensive exfoliated rocky outcrops with weathered, well-drained, coarse to rocky sandy loam soil, and healthy, mature sage scrub and chaparral habitat with an open understory, the San Diego banded gecko will require site-specific considerations and management conditions.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 147,066 acres of sage scrub and chaparral below 1,520 meters in elevation in large core blocks within the Riverside Lowlands and San Jacinto Foothills Bioregions.
Include within the MSHCP Conservation Area at least 7 Core Areas at the San Jacinto foothills (149,750 acres), Lake Skinner-Diamond Valley Lake (29,070 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Santa Ana Mountains (71,490 acres), and Sage/Vail Lake (50,000 acres). Connections between these blocks will be facilitated by upland and riparian connections from Estelle Mountain to Wildomar, Gavilan Hills, San Jacinto River, Temecula Creek, and Tucalota Creek.
Include within the MSHCP Conservation Area suitable microhabitat (e.g., exfoliating granite outcrops, boulderfields, ground debris, yucca stems) within the general habitats to maintain areas for daily cover, hibernation and reproduction purposes.
For purposes of this conservation analysis, potential habitat for the San Diego banded gecko includes coastal sage scrub, chaparral, desert scrubs, and Riversidean alluvial fan scrub within the Riverside Lowlands and San Jacinto Foothills Bioregions below 1,520 meters in elevation. Based on these habitats, the Plan Area supports approximately 272,842 acres of potential habitat for the San Diego banded gecko. Table 1 shows the conservation of potential habitat for the San Diego banded gecko. Approximately 147,066 acres (54 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the San Diego banded gecko. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
SAN DIEGO BANDED GECKO
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 132,074 | 45,822 | 24,170 | 69,992 | 30,755 | 31,327 | 62,082 |
| Coastal Sage Scrub | 133,109 | 43,695 | 27,199 | 70,894 | 19,734 | 42,479 | 62,213 |
| Desert Scrubs | 2,227 | 2,160 | 0 | 2,160 | 38 | 28 | 66 |
| Riversidean Alluvial Fan Sage Scrub | 5,432 | 2,709 | 1,311 | 4,020 | 160 | 1,250 | 1,410 |
| TOTAL | 272,842 | 94,386 | 52,680 | 147,066 | 50,687 | 75,084 | 125,771 |
| 1 Total acres includes habitats within the San Jacinto Foothills and Riverside Lowlands Bioregions below 1,520 meters in elevation. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
As described below under Data Characterization, 15 of the 22 data points have a precision of "1" or "2." Of these 15 locations, 9 (60 percent) would be within the MSHCP Conservation Area. Conservation of this species should be considered from a landscape perspective because the species may be found throughout the Plan Area where rock outcrops exist. As stated earlier, it was estimated that approximately one-fifth of the MSHCP Plan Area supported suitable granitic rock outcrops. The reserve design conserves approximately the same percentage of rock outcrops. While there are definable locations for focusing conservation efforts, there does not appear to be any key populations that would be essential for conservation of the species.
Several large blocks of habitat supporting the San Diego banded gecko would be conserved, including San Jacinto Mountains foothills (foothills portion of Existing Core K; approximately 60,000 acres), Lake Mathews/Lee Lake (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres),Vail Lake/Aguanga (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 25,920 acres), Santa Ana Mountains(Existing Core B; 71,490 acres). However, most every other Core Area within the Riverside Lowlands and San Jacinto Foothills Bioregions below 1,520 meters could also be expected to support San Diego banded gecko if rock outcrops are present.
The distributions of the desert banded gecko (Coleonyx variegatus variegatus) and the San Diego banded gecko (Coleonyx variegatus abbotti) averlap within the Plan Area In order to conserve balance between the two subspecies and possible intergrades, it is necessary to conserve representative populations at the limits of the species distribution and range, including longitude, latitude, and elevation. To this end, the Plan Area contains at least one habitat block at all cardinal compass points and all elevation levels represented within the study. All of these contain, or are expected to contain, the habitat requirements necessary to support healthy gecko populations. Maintenance of rock outcrop clusters and rows, where they exist within the reserve, will be important toward maintaining the genetic diversity of the population.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the San Diego banded gecko. The current population size and local distribution is unknown and estimating population densities is labor intensive.
The MSHCP will conserve large Core Areas and interconnecting habitat linkages that are suitable for occupation by the San Diego banded gecko in the large habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, are unlikely to be at higher risk of extirpation resulting from catastrophic events or demographic or genetic stochasticity due to the species cover utilization, alertness, and known site fidelity and dispersal requirements.
In summary, conservation for the San Diego banded gecko will be achieved by the inclusion of at least 147,066 acres of suitable Conserved Habitat within 7 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size and distribution of the San Diego banded gecko is unknown, however the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
Approximately 125,771 acres (46 percent) of potential habitat for the San Diego banded gecko would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Six (40 percent) of the 15 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However of these, 1 (17 percent) are mapped within existing agriculture and 1 (17 percent) are located in developed or disturbed habitat coverages.
The MSHCP data base includes 22 records for the San Diego banded gecko between 1999 and 1974. Of the 22 records, 8 (36 percent) are precision code "1" (an "x"" and "y" coordinate that allows for good precision in the location), 7 (32 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 7 (32 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). A large number of the precision code "1" or "2" records are relatively recent, with 9 (60 percent) since 1990 and 6 (40 percent) pre-dating 1990 or with no associated date. The reasons for the relative lack of records is likely due to lack of survey effort, cryptic coloration, and nocturnal habits. A fair amount of information exists in the literature, for the banded gecko. However, there is no information in the literature regarding dispersal, and little subspecific information.
The records are scattered from the Plan Area, but are almost exclusively in the Riverside Lowlands and San Jacinto Foothills Bioregions. Other suitable habitat may exist within the National Forests, but only one record was found form the Santa Ana Mountains (south of Lakeland Village). There appear to be no "key" or "core" populations. Record clusters appear to be from singular extensive surveys in a particular area. It is estimated that approximately one-fifth of the MSHCP Plan Area supports granitic outcrops.
Although it is primarily a desert species, Coleonyx variegatus is a microhabitat generalist and also occurs in habitats ranging from cismontane chaparral and desert scrub to open sand dunes and arid tropical forests (Dixon 1970b; Grismer 1988). Rocks, boards, fallen yucca stems, cow dung, and other litter serve as diurnal refuge for the banded gecko. Additionally, it may utilize mammal burrows for refuge (Klauber 1945; Parker and Pianka 1974).
C. v. variegatus (desert banded gecko) is most abundant in sandy flats or desert washes, but is also found from below sea level (desert sinks) to 5,000 feet in all desert habitats up to pinyon-juniper or mixed chaparral (Klauber 1945). C. v. abbotti (San Diego banded gecko) is uncommon but typically found, in coastal scrub and chaparral, preferring granite or rocky outcrops in these habitats (Klauber 1945; Stebbins 1972).
C. variegatus ranges from southern Nevada to the tip of Baja California and south Sinaloa; from coastal southern California east to southwestern New Mexico; and on islands off the western coast of Baja California and in the Gulf of Mexico (Stebbins 1985). C. v. variegatus is common to uncommon in the desert from northern Inyo County south to Mexico. C. v. abbotti is absent in the extreme outer coast, but is present in coastal and cismontane southern California from interior Ventura County south (Klauber 1945; Stebbins 1972).
Two forms of the western banded gecko occur in Riverside County, the San Diego banded gecko, Coleonyx varigatus abbotti, and the desert banded gecko, Coleonyx varigatus variegatus. It is probable that the MSHCP database has point data for both subspecies, though most locations appear to be for C. v. abbottii. These locations include along the Santa Margarita River south of Temecula, in the vicinity of Vail Lake, the vicinity of Lake Skinner, in the hills surrounding the Eastside Reservoir, the Community of San Jacinto, Winchester, Lake Elsinore, west of Lake Mathews in the Santa Ana Mountain foothills, Woodcrest, Moreno Valley, Pigeon Pass, Riverside, variously along the Santa Ana River, Beaumont, and Banning. Questionable locations range north of the San Jacinto Mountains toward the desert.
Key areas include locations where granitic rock outcrops are present in scrub or chaparral habitats.
Genetics: No genetic information was available in the literature, however, some information on taxonomy and systematics was present. Klauber (1945) distinguished the subspecies C. v. abbotti (San Diego banded gecko) from other subspecies by the presence of unbroken (uniform in color) dorsal bands of equal width and a narrow light nuchal band in adults, and the absence of head spotting in adults. The desert banded gecko is distinguished by 7 or fewer preanal pores in males; bands with light centers, or replaced by spots; and a spotted head in adults (Stebbins 1985).
Diet and Foraging: C. variegatus utilizes an opportunistic foraging strategy that is an intermediate between active and ambush strategies. Insects and other arthropods including termites, beetles, spiders, grasshoppers, sowbugs, and insect larvae comprise the banded gecko's diet. Water requirements are fulfilled by moisture in food (Miller and Stebbins 1964).
Cooper (1998) demonstrated that Coleonyx variegatus tongue-flicks and attacks at higher rates in response to prey chemicals than to a pungency control and odorless control. It is hypothesized that both olfaction an vomerolfaction are used by Coleonyx to make adaptively important chemosensory discriminations when pursuing prey items.
The incorporation of vomerolfaction into the foraging strategy as well as a foraging pattern that is intermediate between the classic ‟sit-and-wait" and active patterns may be a function of the gecko's nocturnal habits (Kingsbury 1989). The reasoning for this is twofold, first, vision may be compromised by reduced ambient light levels, and second, nocturnal foragers may be physiologically constrained from ‟too active" a foraging pattern.
Daily Activity: C. variegatus is nocturnal with activity occurring between April and October and peaking in May. Intermittent activity may be displayed by juveniles between November and March (Klauber 1945; Parker 1972). The primary daily activity period is 2 hours after sunset (Klauber 1945; Miller and Stebbins 1964; Kingsbury 1989), although Brattstrom (1952) reports occasional activity in the afternoon to absorb heat.
Kingsbury (1989) observed differences in activity between the sexes. The mean observation time for males (117 minutes after sunset) was significantly later in the evening than for females (94 minutes after sunset). He also found that males were active over a broader range of times and that females were found at lower air temperatures.
The high standard metabolic rate displayed by Coleonyx is likely the result of selection favoring increased activity schedules, greater foraging area, or increased nocturnal vagility (Dial and Grismer 1992).
Reproduction: Male banded geckos emerge in April and attain peak testes size in May followed by testicular regression (Parker 1972). The mating period is between April and May, egglaying occurs between May and September with the highest frequency of gravid females occurring in May and June (Parker 1972). Eggs are probably buried in the ground or under rocks (Mayhew 1968). Clutch size is 2 eggs which are sometimes laid one at a time on different days. Sperm storage occurs in females and can result in multiple clutches per season (2-3) (Mayhew 1968; Parker 1972). The incubation period is approximately 30-45 days. Hatchlings appear from July through November and reach maturity in one year at 52 mm (males) and 56 mm (females) (Stebbins 1954; Fitch 1970; Parker 1972; Miller and Stebbins 1964).
Survival: Tailautotomy is considered an important defense mechanism against predators (Parker 1972; Parker and Pianka 1974). At the approach of a predator, the tail is raised and/or undulated (Johnson and Brodie 1974). At times the lizard presents the tail or hindquarters toward the approaching predator which diverts the predator's attention and leads to increased tail autotomy. Parker and Pianka (1974) noted that this behavior seems to mimic the large scorpions (Hadrurus) found in the same habitat. Loss of the original tail, while allowing survival, may adversely affect the lizard since tail-waving is important in pre-mating behavior (Greenberg 1943).
Bustard (1967) found that banded geckos could survive for 6-9 months (under laboratory conditions) on an amount of food ingested in four days.
Dispersal: There is no information in the literature regarding dispersal.
Socio-Spatial Behavior: Population densities for geckos in Arizona were estimated to be 12-25 geckos/ha (5-10 acres) (Parker 1972). In the Borrego area of San Diego County, Klauber (1945) found an average of 19.4 geckos per 100 miles. Both studies involved driving roads at night while visually searching for geckos.
Fecal sent marking in Coleonyx variegatus was examined by Carpenter and Duvall (1995). They observed discrete defecatoria (preferred defacation sites) for both males and females housed individually. Discrete defecatoria tended to be established away from diurnal resting sites as well as areas marked by conspecifics. Furthermore, when geckos of opposite sex were housed together, they formed more compact defecatoria (versus housing of same sex), suggesting that chemical cues are important in mediating defecation patterns and that geckos are able to recognize the scent of their own feces. Defecatoria may function as "signposts" where geckos obtain information concerning conspecifics, or may serve to reduce predation pressure (Carpenter and Duvall 1995).
Under laboratory conditions, Greenberg (1943) observed that geckos tended to aggregate in shelters during the day. This resulted in aggressive interactions between males which suggests the possibility of territoriality in the field, or a means of sex recognition in a non-sexually dimorphic species.
Community Relationships: Huey and Pianka (1983) suggest that the time of activity may be of little importance in reducing dietary overlap and competition between the banded gecko and other sympatric, diurnal lizards such as whiptails.
Studies have been conducted comparing the movement ecology of Coleonyx variegatus with the short-horned lizard, Phrynosoma douglassii, and western skink, Eumeces skiltonianus. Autumn et al. (1997) tested the nocturnality hypothesis which postulates an evolutionary increase in locomotor performance capacity at low temperature in nocturnal lizards such as Coleonyx. They compared the minimum locomotory costs of Coleonyx variegatus and Phrynosoma douglassii, and found that the minimum cost of locomotion (mcl) for the nocturnal C. variegatus is 58 percent of the mcl of the diurnal P. douglassii. The resulting maximum aerobic speed of the nocturnal lizard was 2.3 times as great as compared to the diurnal P. douglassii. This suggests that geckos evolved a greater capacity for sustained locomotion at low temperature. Additionally, Farley (1996) compared efficiency of locomotion in Coleonyx variegatus and Eumeces skiltonianus and found that nocturnal C.v. variegatus can perform mechanical work during locomotion more efficiently.
Predators of the banded gecko include night snakes, leaf-nosed snakes, western patch-nosed snakes, sidewinders, western diamondback rattlesnakes, coachwhips, and zebra-tailed lizards (Klauber 1945; Funk 1965; and Parker 1972). Tarantulas, large centipedes, solpugids, other rattlesnake species, coyotes, and foxes are other possible predators (Parker 1972).
Dial and Grismer (1992) conducted a study on the physiological-ecological character evolution in the genus Coleonyx and concluded that the high standard metabolic rate (SMR), low evaporative water-loss rate (EWLR), and high thermal preference (TP) found in Coleonyx is derived from the low SMR, high EWLR, and low TP found in the ancestral state.
Autumn, K., C.T. Farley, M. Emshwiller, R.J. Full. 1997. Low cost of locomotion in the banded gecko: a test of the nocturnality hypothesis. Physiological Zoology. Vol. 70, no. 6, pp. 660-669.
Brattstrom, B.H. 1952. The food of the night lizards, genus Xantusia. Copeia 1952:168-172.
Bustard, H.R. 1967. Gekkonid lizards adapt fat storage to desert environments. Science 158:1197-1198.
Carpenter, G., and D. Duvall. 1995. Fecal scent marking in the western banded gecko (Coleonyx variegatus). Herpetologica, vol. 51, no. 1, pp. 33-38.
Cooper, W.E. 1998. Prey discrimination indicated by tongue-flicking in the eublepharid gecko Coleonyx variegatus. Journal of Experimental Zoology, vol. 281, no. 1, pp. 21-25.
Dial, B.E., and L.L. Grismer. 1992. A phylogenetic analysis of physiological-ecological character evolution in the lizard genus Coleonyx and its implications for historical biogeographic reconstruction. Syst. Biol. 41(2):178-195.
Dixon, J.R. 1970. Coleonyx variegatus. Cat. Am. Amphib. Rep. 96:1-4.
Farley, C.T. 1997. Maximum speed and mechanical power output in lizards. Journal of Experimental Biology. Vol. 200, no. 16, pp. 2189-2195.
Farley, C.T., and C.T. Ko. 1997. Mechanics of locomotion in lizards. Journal of Experimental Biology. Vol. 200., no. 16, pp. 2177-2188.
Farley, C.T., M. Emshwiller. 1996. Efficiency of uphill locomotion in nocturnal and diurnal lizards. Journal of Experimental Biology. Vol. 199, no. 3, pp. 587-592.
Fitch, H.S. 1970. Reproductive cycles in lizards and snakes. Univ. Kans. Mus. Nat. Hist. Misc. Publ. 52:1-247.
Funk, R.S. 1965. Food of Crotalus cerastes laterorepens in Yuma County, Arizona. Herpetologica 21:15-17.
Greenberg, B. 1943. Social behavior of the western banded gecko, Coleonyx variegatus Baird. Physiol. Zool. 16: 110-122.
Grismer, L.L. 1983. A reevaluation of the North American gekkonid genus Anarbylus Murphey and its cladistic relationships to Coleonyx Gray. Herpetologica, 39(4):394-399.
Grismer, L.L. 1988. Phylogeny, taxonomy, classification, and biogeography of eublepharid geckos. Pages 369-469 In: Phylogenetic relationships of the lizard families (R. Estes and G. Pregill, eds.). Stanford Univ. Press, Stanford, California.
Grismer, L.L., J.A. McGuire, and B.D. Hollingsworth. 1994. A report on the herpetofauna of the Vizcaino Peninsula, Baja California, Mexico, with a discussion of its biogeographic and taxonomic implications. Bull. So. Cal. Acad. Sci. Vol. 93, no. 2, pp. 45-80.
Huey, R.B., and E.R. Pianka. 1983. Temporal separation of activity and interspecific dietary overlap. Pp. 281-290. IN: R.B. Huey, E.R. Pianka, and T.W. Schoener, eds. Lizard Ecology. Harvard Univ. Press, Cambridge. 501pp.
Johnson, J.A., and E.D.Brodie. 1974. Defensive behavior of the western banded gecko, Coleonyx variegatus. Anim. Behav. 22:684-687.
Kingsbury, B.A. 1989. Factors influencing activity in Coleony variegatus. J. Herpetology 23:399-404.
Klauber, L.M. 1945. Coleonyx varigatus abbotti. Type-locality, ‘‘Proctor Valley, San Diego, California''. Holotype, San Diego Soc. Nat. Hist. (Formerly L.M. Klauber) 34790, collected 28 Feb 1942 by W. Moore.
Klauber, L.M. 1945. The geckos of the genus Coleonyx with descriptions of new subspecies. Trans. San Diego Soc. Nat. Hist. 10:133-216.
Mayhew, W.W. 1968. The biology of desert amphibians and reptiles. Pp. 195-136 IN: G.W. Brown, Jr., ed. Desert Biology, Vol. 1, Academic Press, New York. 638pp.
Miller, A.H., and R.C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument. Univ. Cal. Press, Berkeley. 452pp.
Parker, W.S. 1972. Aspects of the ecology of a Sonoran desert population of the western banded gecko, Coleonyx variegatus (Sauria, Eublepharinae). Am. Midl. Nat. 88:209-220.
Parker, W.S., and E. R., Pianka. 1974. Further ecological observations on the western banded gecko, Coleonyx variegatus. Copeia 1974:528-531.
Stebbins, R.C. 1954.Amphibians and Reptiles of Western North America. McGraw-Hill, NY, 536pp.
Stebbins, R.C. 1972. California amphibians and reptiles. Univ. Cal. Press, Berkeley. 152pp.
Zeiner, D.C., W.F. Laudenslayer, Jr., and K.E. Mayer (Eds.). 1988. California''s Wildlife Volume 1 Amphibians and Reptiles. A Publication of the California Department of Fish and Game. Sacramento, California.
San Diego horned lizard (Phrynosoma coronatum blainvillei)
State: State Protected Species, California Species of Special Concern
Federal: None
The San Diego horned lizard population is widespread throughout the Plan Area. The horned lizard occurs primarily in scrub, chaparral, and grassland habitats. The species is common in most areas of the Plan Area except where adjacent to urban situations. No specific management regimes are needed to maintain this species, although management of habitat for species such as the California gnatcatcher, Stephens' kangaroo rat, San Bernardino kangaroo rat, and Los Angeles pocket mouse may benefit the horned lizard.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 407,036 acres of scrub, chaparral, woodland and grassland habitat. The majority of habitat conservation will occur in large blocks within the Plan Area.
Include within the MSHCP Conservation Area at least 13 Core Areas at the Santa Rosa Plateau (8,360 acres), Lake Skinner-Diamond Valley Lake (29,070 acres), Lake Mathews-Estelle Mountain (31,180 acres), San Jacinto Wildlife Area-Lake Perris (17,470 acres), the Badlands (24,920 acres), Potrero Valley (10,000 acres), the Banning Bench (9,610 acres), Sage/Vail Lake (50,000 acres), Anza Valley (4,290 acres), Agua Tibia Wilderness (10,460 acres), Paloma Valley/Hogbacks (5,050 acres), Santa Ana Mountain foothills (71,490 acres), and Santa Ana River (10,740 acres).
For purposes of this conservation analysis, potential habitat for the San Diego horned lizard includes grasslands, coastal sage scrub, chaparral, desert scrubs, and Riversidean alluvial fan scrub at all elevation levels within the Plan Area. Based on these habitats, the Plan Area supports approximately 729,570 acres of potential habitat for the San Diego horned lizard. Table 1 shows the conservation of potential habitat for the San Diego horned lizard. Approximately 407,036 acres (56 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the San Diego horned lizard. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
As described below under Data Characterization, 135 of the 215 data points have a precision of "1" or "2." Of these 135 locations, 57 (42 percent) would be within the MSHCP Conservation Area. Conservation of this species should be considered from a landscape perspective because the species is found throughout the Plan Area and may occur in a variety of habitats. While there are definable locations for focusing conservation efforts, there does not appear to be any key populations that would be essential for conservation of the species.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
SAN DIEGO HORNED LIZARD
| Vegetation Type | MSHCP Plan Area (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area1 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Coastal Sage Scrub | 152,686 | 47,161 | 34,555 | 81,716 | 26,241 | 44,729 | 70,970 |
| Desert Scrubs | 9,378 | 3,675 | 1,314 | 4,989 | 44 | 4,345 | 4,389 |
| Grassland | 146,869 | 20,011 | 22,806 | 42,817 | 12,223 | 91,829 | 104,052 |
| Chaparral | 413,488 | 64,899 | 207,381 | 272,280 | 59,582 | 81,626 | 141,210 |
| Riversidean Alluvial Fan Sage Scrub | 7,149 | 3,171 | 2,063 | 5,234 | 217 | 1,697 | 1,915 |
| TOTAL | 729,570 | 138,917 | 268,119 | 407,036 | 98,307 | 224,226 | 322,536 |
| 1 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. | |||||||
Nothing is known about genetic relationships between San Diego horned lizards within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However it is generally thought that in the absence of data, it is best to preserve representative populations at the limits of its distribution and range, including latitude, longitude, and elevation. Accordingly, large habitat blocks important to the horned lizard are distributed throughout the MSHCP Conservation Area within the following Core Areas: Lake Mathews/Lee Lake (Existing Core C plus Proposed Extended Core 2 and Proposed Core 1; 31,180 acres), Santa Rosa Plateau (Existing Core F; 8,360 acres), Vail Lake/Aguanga (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Badlands (Proposed Core 3; 24,920 acres), Potrero Valley (northwestern portion of Existing Core K only; approximately 10,000 acres), Banning Bench (Existing Core I; 9,610 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Wilderness (Existing Core M; 71,490 acres), Santa Ana Mountains foothills (Existing Core B; 10,460 acres), Santa Ana River (Existing Core A; 10,740 acres), and Paloma Valley/Hogbacks (Proposed Core 2: 5,050 acres). All of these contain, or are expected to contain, the habitat requirements necessary to support San Diego horned lizard populations. In addition, linkages between the blocks of habitat will be conserved. In nearly all cases, the linkages would include potential habitat for horned lizards. In nearly all cases, the habitat linkages would function as functional territories for the horned lizards. Although minimum dispersal distance is not reported for San Diego horned lizards, they have been described as having small home ranges (Munger 1984). Most of the linkages could accommodate small home ranges and genetic exchange through the reserve would take place over the long term.
Numerous smaller habitat areas would likely be isolated from other habitat by development or high density roadways. These areas include the Jurupa Mountains (Proposed Noncontiguous Habitat Block 2; 1,230 acres), Box Springs Mountain (Existing Noncontiguous Habitat Block A and Constrained Linkage 8; 2,920 acres), Steele Peak/Gavilan Hills/Gavilan Plateau (Proposed Linkage 3; 5,540 acres), Sycamore Canyon Regional Park/March Air Force Base (Existing Core D; 2,510 acres), West Hemet (Proposed Noncontiguous Habitat Block 7; 1,250 acres), and Motte-Rimrock Reserve (Proposed Noncontiguous Habitat Block 4; 1,150 acres) among others. These areas are expected to continue to support horned lizard populations, though they will be subject to increased collecting, predation, loss of requisite prey species due to displacement, or catastrophic events such as fire. In areas proximate to development, requisite prey species (native harvester ants) are more likely to be displaced by non-native Argentine ants, thereby removing a critical life history requirement.
Movement across large roads and freeways will be hindered in areas without large vehicular overpasses. It is unlikely that reptiles, including the San Diego horned lizard, will utilize long and narrow undercrossings to occupy new habitat and over-road movement of reptiles will likely result in mortality. Some successful movement of reptiles is expected under bridges greater than 50 feet in length.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the San Diego horned lizard. The current population size is unknown but the San Diego horned lizard appears to be locally common in suitable habitat, as evidenced by its widespread distribution. Horned lizards are cryptic animals which utilize ground resources exclusively.
The MSHCP will conserve large Core Areas and interconnecting habitat linkages that are suitable for occupation by the San Diego horned lizard in the large habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, may be at higher risk of extirpation either rapidly as a result of some catastrophic event, or over the longer term as a result of demographic or genetic stochasticity (e.g., random birth and death rates, inbreeding depression, genetic drift) or through indirect impacts (e.g., loss of suitable prey) from surrounding urbanization.
In summary, conservation for the San Diego horned lizard will be achieved by the inclusion of at least 407,036 acres of suitable Conserved Habitat within 13 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size of the horned lizard is unknown, but the general distribution is, and a relatively sizable database is present within the UCR database. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
Approximately 322,536 acres (44 percent) of potential habitat for the San Diego horned lizard would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Seventy-eight (56 percent) of the 135 precision code "1" or "2" records would be outside the MSHCP Conservation Area. However of these, 9 (12 percent) are mapped within existing agriculture and 20 (26 percent) are located in developed or disturbed habitat coverages. Forty-nine (63 percent) are in chaparral, coastal sage scrub, woodlands and forests, and non-native grassland habitats.
The MSHCP data base includes 215 records for the San Diego horned lizard between 1999 and 1908. Of the 215 records, 57 (27 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 78 (36 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 80 (37 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). A large number of the precision code "1" or "2" records are relatively recent, with 46 (34 percent) since 1990 and 89 (66 percent) pre-dating 1990 or with no associated date. The reason for the lack of more recent locations is likely due to a large historical data base dating to the early 1900's. Abundant information is available for P. c. blainvillei, however, more information is needed regarding dispersal, hibernation site requirements, and population dependance on native ants.
The records are scattered from the Plan Area with a number of records from the higher elevations of the various mountain ranges. Because the records are generally evenly distributed throughout the Plan Area, there are no definable "key" or "core" populations. However, there are a few lightly clustered areas within the Plan Area. These include the Lake Elsinore area, Highgrove area, Good Hope area, Murrieta Hot Springs area, Aguanga area, Banning area, Lake Hemet area, and Lake Skinner area.
P. c. blainvillei is found in a wide variety of vegetation types including coastal sage scrub, annual grassland, chaparral, oak woodland, riparian woodland and coniferous forest (Klauber, 1939; Stebbins, 1954). In inland areas, this species is restricted to areas with pockets of open microhabitat, created by disturbance (e.g., floods, fire, roads, grazed areas, fire breaks) (Jennings and Hayes, 1994).
Historically, Phrynosoma c. blainvillei was distributed from the Transverse Ranges in Kern, Los Angeles, Santa Barbara, and Ventura counties southward through the Peninsular Ranges of southern California to Baja California (Jennings, 1988). P. c. blainvillei seems to have disappeared from about 45 percent of its former range in southern California, in particular on the coastal plain where it was once common (Hayes and Guyer, 1981) and in riparian and coastal sage scrub habitats on the old alluvial fans of the southern California coastal plain (Bryant, 1911, Van Denburgh, 1922). In California, Phrynosoma c. blainvillei ranges from the Transverse Ranges south to the Mexican border west of the deserts, although the taxon occurs on scattered sites along the extreme western desert slope of the Peninsular Ranges (Jennings, 1988). The known elevation range of this species is from 10 meters at the El Segundo dunes (Los Angeles County) to approximately 2,130 meters at Tahquitz Meadow, on San Jacinto Mountain, in Riverside County. Phrynosoma c. blainvillei is thought to intergrade with P. c. frontale in extreme southern Kern county and northern Santa Barbara, Ventura, and Los Angeles counties (Reeve, 1952; Montanucci, 1968; Jennings, 1988).
This species is distributed throughout western Riverside County. No specific population aggregations are apparent within the Plan Area.
Suitable habitats up to 2,100 meters in elevation.
Genetics: According to Montanucci (1989), specialization for myrmecophagy (ant-eating) in Phrynosoma appears to have involved the following morphological changes: (1) a reduction or loss of the epipterygoid; (2) reduction of the coronoid process; (3) reduction in the diameter of the mandibular ramus; (4) reduction in the area posterior to the coronoid process, and a concomitant increase in the length of the tooth row, possibly accomplished by a slight shift in the position of the coronoid. In addition to morphology and dietary information, behavioral information also corroborates the specialization for myrmecophagy in Phrynosoma (Montanucci, 1989).
Diet and Foraging: Horned lizards of the genus Phrynosoma are primarily ant-eating reptiles whose dietary habits are well known (Montanucci, 1981; Pianka and Parker, 1975; Powell and Russell, 1984; Rissing, 1981; Turner and Medica, 1982). Up to 90 percent of the diet of P. c. blainvillei consists of native harvester ants (Pogonomyrmex spp.) (Pianka and Parker, 1975), and this species does not appear to eat non-native Argentine ants (Jennings and Hayes, 1994) that have replaced native ants in much of southern California (Ward, 1987). Other slow moving insects, such as beetles, flies, and caterpillars are consumed opportunistically when encountered (Presch, 1969; Pianka and Parker, 1975).
Whitford and Bryant (1979) studied the predator and prey relationship of the closely related phrynosoma cornutum and determined some interesting results which may apply to P. coronatum since they are so closely related and share the same resource base. They found two ant species to be the most important prey for P. cornutum: Pogonomyrmex desertorum and Pogonomyrmex rugosus; P. californicus was also found to be a prey item, however, because few colonies are active during the summer when horned lizards are active, it was considered a minor prey species. They found that at a single stop, the maximum number of ants eaten by P. cornutum per species was: 18 P. californicus, 29 P. rugosus, and 25 P. desertorum. The dietary species composition of individual horned lizards varied from one species to four and the total number of ants ingested in a day varied from approximately 30 to >100 per day.
In addition, Whitford and Bryant (1979) found that the lizards feed most often on ants that were not associated with nest discs or foraging columns and took only a few ants at any one place. When active, P. rugosus was preferred over P. desertorum (based on a larger number taken), however they did not completely switch to P. rugosus. Because P. rugosus activity was found to be unreliable, alternate prey is expected to be utilized (Whitford & Bryant, 1979). Hatchling P. cornutum was found by Whitford & Bryant to feed exclusively on P. rugosus and P. desertorum, "taking an average of three harvester ants per bout and retreating to the shelter of a low shrub or grass where they remained for about 20-30 minutes before feeding again."
Daily Activity: The daily diurnal activity of P. c. blainvillei is distinctive. As surface temperatures reach >19oC (almost 15 degrees Celsius below temperatures of normal activity), just prior to sunrise, this taxon emerges from burial sites in the substrate into a position that allows them to bask in the first rays of the sun (Heath, 1965; Hagar, 1992). Heath (1962) found that two distinct behavior patterns initiate daily activity; (1) the lizards "may move upward in the sand until their heads are exposed and remain in this position until warmed to their activity levels; (2) alternately, they emerge completely and begin basking in a fully exposed position." He also found a similarity in emergence times between two groups of P. coronatum and P. cornutum, suggesting the operation of an endogenous or circadian rhythm.
High site fidelity is often exhibited by P. c. blainvillei, as effective thermoregulation (optimum: 29-39 degrees Celsius) requires familiarity with their surroundings (Heath, 1965). Midday temperatures over 40oC are avoided as P. c. blainvillei bury themselves in the substrate, reemerging in the later afternoon to resume full activities (e.g., feeding, territorial, and reproductive).
Tollesturp's (1981) observations suggest that olfactory cues are important in Phrynosoma's daily activities, including courtship, feeding, sex recognition, and conspecific interactions. In addition, they were observed to apparently mark sites by partially extruding the cloaca and rubbing it back and forth on the substrate.
Contrary to Heath (1962), Whitford and Bryant (1979) did not observe activity in P. cornutum until approximately two hours after sunrise, and most feeding and other activity was confined to the morning hours. Typical morning activity observed by Whitford and Bryant involved "sitting for 30 seconds to several minutes, walking followed by elevated sitting, lasting from a few seconds to several minutes, terminated by a feeding bout or further walking, then resumption of elevated sitting." They also found that a significant portion of the daily activity of P. cornutum involves shrub climbing and movement in the shrub canopy. Through the middle part of the day, the lizards positioned themselves in a shrub canopy where the ambient temps ranged from 35 to 40 degrees C. Their feeding corresponded with the peak activity patterns of harvester ants, between the hours of 0900 and 1100 (Whitford and Ettershank, 1975; Whitford, et. al., 1976). As expected, the bulk of thermoregulatory basking occurred in the early morning and late afternoon.
Reproduction: In southern California, the male reproductive cycle begins during mid to late March and ends in June as testes decrease in size. Testes become their maximum size during Spring with sperminogenesis in progress (Goldberg, 1983). Female P. c. blainvillei are oviparous, laying a clutch of 6-17 eggs between May and July each year (Stebbins, 1954; Howard, 1974; Goldberg, 1983). Hatchlings appear in late July to early August, and require 2 - 3 years to reach reproductive age (Stebbins, 1954; Howard, 1974; Pianka and Parker, 1975; Goldberg, 1983).
After reviewing the data (Stebbins, 1954; Pianka and Parker, 1975; Howard, 1974), Goldberg (1983) found a range of average clutch sizes from various studies ranging from 11 to 12.5 individuals. Goldberg (1983) also found that P. coronatum has the potential to produce multiple clutches during the Spring.
Survival: The defense that P. c. blainvillei most often uses against approaching predators is to depend on their cryptic appearance and simply lie motionless (Jennings and Hayes, 1994). Klauber (1939) documented change in body coloration to match the soil or sand on which they were found. Other methods used include hissing, inflating lungs to increase apparent size (Pianka and Parker, 1975; Munger, 1986; Sherbrooke, 1981), raising their horns by lowering their snout (Pianka and Parker, 1975; Sherbrooke, 1981), squirting blood from the corner of the eye (which seems to repel dogs and cats) (Presch, 1969; Pianka and Parker, 1975), tilting the body when irritated (Milne and Milne, 1950; Smith, 1946; Tollestrup, 1981), presenting a bristling of scales of the back while standing well up on the legs (Bryant, 1911), and running a short distance before flattening out or burrowing several centimeters under the ground (Presch, 1969). When P. coronatum flattens its body, it usually tucks its head down, exposing its horns, and often charges the enemy (Winton, 1916). An additional defense mechanism may be based on learned avoidance by predators suggested by reports of snakes dying while trying to swallow Phrynosoma which are well documented in the literature (Klauber, 1972; Milne and Milne, 1950; Van Denburgh, 1922; Vorhies, 1948; Wright and Wright, 1957).
The work conducted by Whitford and Bryant (1979) suggests that the coevolution of a foraging strategy in relation to the responses of their prey has allowed the horned lizard to survive with a potentially limited resource base.
Dispersal: No information on dispersal is available.
Socio-Spatial Behavior: The literature contains conflicting data on the social behavior of P. coronatum. According to Carpenter (1967), the typical pattern of Iguanid courtship includes push-ups, head-bobs, a prancing strut, grasping of the female by the nape of the neck, and male mounting the female dorsally (Carpenter, 1967; Carpenter and Ferguson, 1977). Lynn (1965) found "no evidence of territoriality, no evidence of any type of social hierarchy, no evidence that the display (head-bob/push-up) is used in sex or species recognition, and no evidence that the display is used on courtship." Stamps (1977) speculates that horned lizards have only simplified displays and lack territorial defense.
Contrary to these reports, Tollestrup (1981) found that P. coronatum utilizes a diverse repertoire of displays for species recognition, courtship and sex; including head-bob (a vertical motion of the head; (Lynn (1965) described this as "three (sometimes four) quick bobs, a bob with a quick upward movement and a slow downward movement, a slow bob); push-up (an extension of the forelimbs that raises the front part of the body); tail-curled-up (with all four limbs extended or the body pressed flat against the substrate, the tail is curled up over the body); and scratching (the two forelimbs are moved alternately with a scratching or pawing motion usually without the claws in contact with the substrate).
Tollestrup (1981) observed that displays between males are usually performed from an elevated perch such as a gopher mound or cow dung, and are characterized by a frequency increase in head-bobs and push-ups, and by the use of the rocking display. One male would then run toward the other, each continuing to display. "Males presented their vents with their tails curled up over the back to other males and in each case, the male with the curled tail moved out of the area" (Tollestrup 1981). Tollestrup observed no biting or combat with the horns.
Using a radiotelemetry study, Munger (1984) found that horned lizards utilize limited home ranges, occupying areas much smaller than they would if they moved randomly. His data further suggest that there is a reduction in home range overlap, and contrary to expectation, overlap between sexes tended to be less than overlap between individuals of the same sex (Munger, 1984).
In Whitford and Bryant's 1979 study, the closely related P. cornutum moved an average of 46.8 meters per day (range = 9-91 m). They also found that an individual horned lizard moved over a zigzag course during a day but rarely crossed its own trail.
Community Relationships: Munger (1984) poses two theories regarding the reduction in limited home range overlap; head bobbing may be a form of low level home range defense; or it may be mutual voluntary avoidance related to resource availability. The second theory is based on the idea that "areas occupied by other horned lizards are likely to have been recently harvested and thus may be unavailable to subsequent harvesting. Horned lizards that avoid the home ranges of others would thereby avoid areas of reduced resource availability" (Munger 1984). Whitford and Bryant (1979) found data that supports the second theory.
To determine the relationship between the horned lizard and its prey, Whitford and Bryant (1979) conducted artificial predation studies to determine the ant's response to predation by the lizard (the closely related P. cornutum), and consequently the predatory tactics employed by the lizard to maximize the availability of its prey. They found that the horned lizard has evolved a foraging strategy that allows maximization of prey availability over weeks or a month rather than per hour or day. The data suggests that horned lizards are regulated by the availability and productivity of Pogonomyrmex spp. The estimates of horned lizard densities, ingestion rates, and numbers of potential prey also suggest that Pogonomyrmex spp. colonies are extremely productive, more or less replacing the entire worker population each year. "Even allowing for large errors in these estimates, it is apparent that the horned lizard population is utilizing the harvester ants at or close to the maximum exploitation level" (Whitford and Bryant, 1979). Further, "these estimates suggest that no other lizards or other potential predators should utilize these harvester ants." In over six years of studying these ants, Whitford and Bryant have reported only two incidents of predation by species other than Phrynosoma cornutum: one by a robber fly (Ascilidae) and one by a sun spider (Solpugidae). The coast horned lizard presumably fills the same habitat niche in Riverside (feeding on the same prey), as P. cornutum does in Texas, hence we may apply similar hypotheses in prey utilization rates.
Whitford & Bryant (1979) observed no disruption in foraging behavior in Pogonomyrmex desertorum when the ants were in close proximity to the horned lizard. However, an avoidance response was twice observed in a P. rugosus foraging column when a horned lizard came near. When the lizard made moves to capture prey, other ants in the column became immobile, assuming a vertical position either on the soil surface, or while clinging to a grass blade. The result was a rapid cessation of activity in the column of foragers, which was held for 10-15 minutes.
Differences in the numbers of ants taken per bout and an average time between ants was found when comparing feeding bouts at a nest disk to a foraging trail or at some distance from a nest disk or trail. The average time between captures was low when P. rugosus and P. californicus were active. Average time between captures was also found to be lower for P. rugosus when in the open than at a nest disk or column, possibly due to the predation-avoidance behavior of P. rugosus.
Simulated predation on the harvester ants had interesting results. Simulated predation at certain levels was found to affect P. rugosus during the day, however, it had no effect on P. rugosus colonies foraging at night. A level of 25 percent removal of estimated foragers had no observable effect on P. rugosus. At 50 percent removal, 7 out of 10 colonies ceased activity for 10 days, the remaining colonies showed decreased activity. At extreme levels of predation (75 percent removal), half of the colonies remained active, engaging in frenzied foraging to provide food for the developing brood. All colonies subjected to simulated predation resumed activity in 10 days.
"The response of the individual-foraging, small colony P. desertorum differed from P. rugosus in that colonies experiencing 25 percent reduction in numbers of foragers remained active; or the number of active colonies was not significantly different from the control" (Whitford and Bryant, 1979). When an approximately 50 percent loss of estimated foragers was applied to colonies of P. desertorum, activity largely ceased during the first five days after forager removal and half of the colonies tested remained closed up to 10 days after the simulated predation (Whitford and Bryant, 1979).
Simulated predation affected intensity of foraging activity (as estimated by the number of workers returning to the colony per minute), as well as the relative number of colonies that were active. When simulated predation was applied at a constant rate, activity ceased in P. desertorum at a point which resulted in much lower total losses than when a fixed percentage of the workers was removed at one time (Whitford and Bryant, 1979). Even when rainfall stimulated activity in the control colonies, most of the colonies which had experienced predation remained closed.
These data suggest that the horned lizard has coevolved a foraging strategy in relation to the responses of their prey and this has allowed it to survive with a potentially limited resource base.
The specialized diet and habitat requirements, site fidelity, and cryptic defense behavior make P. c. blainvillei highly vulnerable. Commercial collecting, and habitat loss due to agriculture and urbanization are the main reasons cited for the decline of this taxa. Most surviving populations inhabit upland sites with limited optimal habitat. Many of these sites are on marginally suitable Forest Service land (Jennings and Hayes, 1994). However, the most insidious threat to P. c. blainvillei is the continued elimination of its food base by exotic ants. Argentine ants colonize around disturbed soils associated with building foundations, roads and landfills, and expand into adjacent areas, eliminating native ant colonies (Ward, 1987). Under these conditions P. c. blainvillei populations have become increasingly fragmented, and have undergone the added stress of a number of other factors, including fire, grazing, off-road vehicles, domestic cats, and development (Jennings and Hayes, 1994). This taxon is unable to survive habitats altered by development, agriculture, off-road vehicle use, or flood control structures (Goldberg, 1983).
P. c. blainvillei emerges from hibernation in March, and becomes surface active in April through July, after which most adults estivate (summer hibernation) (Hagar, 1992). The adults reappear again briefly in late summer and return to overwintering sites between August and early October depending upon elevation (Klauber, 1939; Howard, 1974; Hagar, 1992).
Baur, B. 1979. Pfledge und "Zucht" der Reisenkrotenechse, Phrynosoma asio (reptilia: Sauria: Iguanidae). Salamandra 15:1-12.
Bruner, H.L. 1907. On the cephalic veins and sinuses of reptiles, with description of a mechanism for raising the venous blood pressure in the head. Amer. Jour. Anat., 7:1-117, 17 figs., 3 pls.
Bryant, H. C. 1911. The horned lizards of California and Nevada of the genera Phrynosoma and Anota. Univer. California Publ. Zool. 9:1-84.
Burleson G.L. 1942. The source of blood ejected from the eye by horned toads. Copeia 1942, No. 4. Dec 28. Pp. 246-248. Herpetologica. 1989. 45(2). Pp 208-216.
Carpenter, C. 1962. Aggression and social structure of iguanid lizards. Pp. 87-105 In: W.W. Milstead (Ed.), Lizard Ecology: A symposium. Univ. Missouri Press, Columbia.
Carpenter, C. 1967. Aggression and social structure of iguanid lizards. Pp. 87-105. IN:W.W. Milstead (Ed.), Lizard Ecology: A Symposium. Univ. Missouri Press, Columbia.
Carpenter, C.C. and G.W. Ferguson. 1977. Variation and evolution of stereotyped behavior in reptiles. Pp. 335-554. In: C Gans and D.W. Tinkle (Ed.), Biology of the Reptilia. Vol 7. Academic Press, London.
Goldberg, S.R. 1983. The reproduction of the coast horned lizard, Phrynosoma coronatum in Southern California. The Southwestern Naturalist. Vol 28, No. 4 Pp. 478-479.
Grey (1946)- San Diego horned Lizard Phrynosoma coronatum blainvillei. In: Smith H.M. 1946. Handbook of Lizards. Pp. 293-295. Comstock Publ. Assoc., Ithaca, New York.
Hagar, S. B. 1992. Surface activity, movement, and home range of the San Diego horned lizard, Phrynosoma coronatum blainvillei. Master''s Thesis, California State University, Fullerton.
Hayes, M. P., and C. Guyer. 1981. The herpetofauna of Ballona. Pp. H1 - H80 In: R. W. Schreiber (editor), The biota of the Ballona region, Los Angeles County. Supplement I, Marina Del Rey/Ballona Local Coastal Plan, Los Angeles County Natural History Museum Foundation, Los Angeles, California.
Heath, J. E. 1965. Temperature regulation and diurnal activity in horned lizards. Univ. California Publ. Zool. 64:97-136.
Heath, J.E. 1962. Temperature-Independent morning Emergence in Lizards of the Genus Phrynosoma. Science. Vol 138. Pp. 891-892.
Howard, C. W. 1974. Comparative reproductive ecology of horned lizards (genus Phrynosoma) in southwestern United States and northern Mexico. Journal of the Arizona Academy of Science 9(3):108-116.
Jennings, M. R. 1988. Phrynosoma coronatum. Catalogue of American Amphibians and Reptiles:428.1-428.5.
Jennings, M. R., and M. P. Hayes. 1994. Amphibian and reptile Species of Special Concern in California. Final report submitted to California Department of Fish and Game, Inland Fisheries Division, Rancho Cordova, California, under Contract 8023.
Klauber, L. M. 1972. Rattlesnakes, Their Habits, Life Histories, and Influence on Mankind. Univ. Calif. Press, Berkeley and Los Angeles, California. Southwestern Naturalist 28(4):478-479.
Klauber, L. M. 1939. Studies of reptiles life in the arid southwest. Part I, Night collecting on the desert with ecological statistics; Part II, Speculations on protective coloration and protective reflectivity; Part III, Notes on some lizards of the southwestern United States. Bulletin of the Zoological Society of San Diego (14):1-100.
Lynn, R.T. 1965. A comparative study of display behaviour in Phrynosoma (Iguanidae). Southwest nat. 10:25-30.
Milne, L.J., and M.J. Milne. 1950. Notes on the behaviour of horne toads. Amer. Midl. Nat. 44:720-741.
Milne, L.J. 1938. Mating of Phrynosoma coronatum. Copeia 1938:200-201.
Montanucci, R. R. 1968. Notes on the distribution and ecology of some lizards in the San Joaquin Valley, California. Herpetologica 24(4):316-320.
Montanucci, R.R. 1981. Habitat separation between Phrynosoma douglassi and P. orbiculare (Lacertlia: Iguanidae) in Mexico. Copeia 1981:147-153.
Montanucci, R.R. 1989. The relationship of morphology to diet in the horned lizard genus Phrynosoma. Herpetologica. 1989. 45(2), pp 208-216.
Munger, J.C. 1984. Home Ranges of Horned Lizards (Phrynosoma): circumscribed or exclusive? Oecologica (Berlin) 62:351-360.
Munger, J.C. 1984. Home ranges of horned lizards (Phrynosoma): circumscribed and exclusive? Oecologia (Berlin) (1984) 62:351-360.
Pianka, E. R., and W. S. Parker. 1975. Ecology of horned lizards: A review with special reference to Phrynosoma platyrhinos. Copeia 1975(1):141-162.
San Diego mountain kingsnake (Lampropeltis zonata pulchra) & San Bernardino mountain kingsnake (Lampropeltis zonata parvirubra)
State: Species of Special Concern
Federal: None
The mountain kingsnake populations are narrowly defined within the Plan Area. The San Diego mountain kingsnake is only known to occur within the Santa Ana Mountains, Aqua-Tibia Mountains, and Desert Transition Bioregions above 500 meters in elevation (Fisher and Case, 1997). The San Bernardino mountain kingsnake is only known to occur within the San Bernardino Mountains and San Jacinto Mountains bioregions above 1,500 meters (Fisher and Case, 1997). Both species are restricted to rock outcrops, talus, and steep shady canyons within coniferous and mixed coniferous, hardwood, or riparian woodlands and other edge habitats when associated with coniferous habitat. It is anticipated that these species' will respond to a landscape level of management. Because the San Diego and San Bernardino mountain kingsnakes are largely restricted to US Forest Service lands, coverage is dependent on management commitments from the US Forest Service.
The species-specific conservation objectives developed for these species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 7,708 acres of montane coniferous forest, deciduous woodlands and forest, riparian scrub, woodland, and forest above 500 meters in elevation within the Santa Ana Mountains, Agua-Tibia Mountains, and Desert Transition Bioregions for the San Diego mountain kingsnake.
Include within the MSHCP Conservation Area at least 22,159 acres of montane coniferous forest, deciduous woodlands and forest, riparian scrub, woodland, and forest between above 1500 meters in elevation within the San Jacinto Mountains and San Bernardino Mountains Bioregions for the San Bernardino mountain kingsnake.
For each subspecies, conserved habitat will include linkages between conserved areas.
Include within the MSHCP Conservation Area suitable microhabitat (e.g., rock outcrops, talus, and steep shady canyons) within coniferous and mixed coniferous, hardwood, or riparian woodlands.
San Diego mountain kingsnake: For purposes of this conservation analysis, suitable habitat for this species includes all montane wooded (conifer and hardwood) habitats and interspersed riparian habitats above 500 meters in the Santa Ana Mountains, Palomar Mountains, and Santa Rosa Mountains (Santa Ana Mountains, Aqua-Tibia Mountains, and Desert Transition Bioregions). Acreages for these habitats have been combined within three categories (Woodlands and Forests; Riparian Scrub, Woodland, and Forest; and Montane Coniferous Forest) and are provided in Table 1 below. Due to the lack of data points (see below), species conservation cannot be based on species occurrence preservation. Instead, conservation must be based on habitat preservation within the appropriate Bioregions as directed by the known habitat characteristics of this sub-species. Based on these habitats, the Plan Area supports approximately 10,432 acres of potential habitat for the San Diego mountain kingsnake. Table 1 shows the conservation of potential habitat for the San Diego mountain kingsnake. Approximately 7,708 acres (74 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the San Diego mountain kingsnake. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
SAN DIEGO MOUNTAIN KINGSNAKE
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Montane Coniferous Forest | 102 | 0 | 102 | 102 | 0 | 0 | 0 |
| Riparian Scrub, Woodland and Forest | 1,037 | 164 | 584 | 748 | 69 | 219 | 288 |
| Woodlands and Forest | 9,293 | 551 | 6,307 | 6,858 | 2,184 | 251 | 2,435 |
| TOTAL | 10,432 | 717 | 6,997 | 7,708 | 2,253 | 470 | 2,723 |
| 1 Total acres include habitats within the Santa Ana Mountains, Aqua-Tibia Mountains, and Desert Transition Bioregions above 500 meters. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
As described below under Data Characterization, there are no data points for this sub-species, therefore preservation based on known species occurrence is not feasible.
Conservation of the San Diego mountain kingsnake should be considered from a landscape perspective because the species may be found throughout the Santa Ana Mountains, Agua-Tibia Mountains, and Desert Transition Bioregions in suitable habitat, and conservation based on species occurrence is not feasible due to paucity of data. To manage threats to the species, the Forest Service will need to address poaching, development, firewood harvesting, commercial timber harvesting, fire management, and land exchanges. Poaching not only removes individuals from the breeding population, but also may result in permanent habitat loss in some cases, if rocks are pried apart and fallen wood is shredded. Firewood harvesting, fire management, and collection of fallen wood removes the ground debris that is a limiting habitat requirement for this species.
San Bernardino mountain kingsnake: For purposes of this conservation analysis, suitable habitat for this species includes all montane wooded (conifer and hardwood) habitats and interspersed riparian habitats above 1,500 meters in elevation within the San Bernardino Mountains and San Jacinto Mountains (San Jacinto Mountains and San Bernardino Mountains Bioregions). While other habitats have been known to support mountain kingsnakes, these habitats are always associated with the above habitats and are secondary. They are therefore not included in this assessment, because they would skew the analysis. Acreages for these habitats have been combined within three categories (Woodlands and Forests; Riparian Scrub, Woodland, and Forest; and Montane Coniferous Forest) and are provided in Table 2 below. Due to the paucity of data points (see below), species conservation can not be based on species occurrence preservation. Instead, conservation must be based on habitat preservation within the appropriate Bioregions as directed by the known habitat characteristics of this sub-species. Based on these habitats, the Plan Area supports approximately 29,725 acres of potential habitat for the San Bernardino mountain kingsnake. Table 1 shows the conservation of potential habitat for the San Bernardino mountain kingsnake. Approximately 22,159 acres (75 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the San Bernardino Mountain kingsnake. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
TABLE 2
SUMMARY OF HABITAT CONSERVATION
SAN BERNARDINO MOUNTAIN KINGSNAKE
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Montane Coniferous Forest | 21,779 | 0 | 15,023 | 15,023 | 1 | 6,754 | 6,755 |
| Riparian Scrub, Woodland and Forest | 55 | 0 | 39 | 39 | 0 | 16 | 16 |
| Woodlands and Forest | 7,891 | 0 | 7,092 | 7,092 | 4 | 794 | 798 |
| TOTAL | 29,725 | 0 | 22,159 | 22,159 | 5 | 7,565 | 7,571 |
| 1 Total acres includes habitats within the San Jacinto Mountains and San Bernardino Mountains Bioregions above 1,500 meters. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
As described below under Data Characterization, there are few records of the San Bernardino mountain kingsnake, and most of the records are old or undated, therefore preservation based on species occurrence is not feasible. Species conservation will be habitat based, using elevation and habitats within appropriate Bioregions as a guide. Nearly all of the potential habitat is situated in and around U.S. Forest Service lands. These lands include the following Management Areas, Wilderness Areas, Range Allotments, and Roadless Areas as determined by the U.S. Forest Service: San Jacinto Wilderness (approximately 4,100 acres), San Jacinto Management Area (approximately 40,000 acres; includes roadless areas around Rouse Hill and Horse Creek Ridge and portions of the Rouse and Garner Range Allotments), Soboba Management Area (25,000 acres), Mount San Jacinto Wilderness State Park, Garner Management Area (17,500 acres; mostly covered by the Garner and Wellman Range Allotments), Pyramid Management Area (5,000 acres; Partially covered by the Pyramid Peak A Roadless Area and entirely covered by the Wellman Range Allotment), and Bautista Management Area (30,000 acres; Area is dominated by roadless areas on Rouse Hill, Hixon Flat, and Cahuilla Mountain, and is approximately half covered by the Rouse Range Allotment).
Conservation of the San Bernardino mountain kingsnake should be considered from a landscape perspective because the species may be found throughout the San Jacinto Mountains and San Bernardino Mountains Bioregions in suitable habitat, and conservation based on species occurrence is not feasible due to paucity of data. To manage threats to the species, the Forest Service will need to address poaching, development, firewood harvesting, commercial timber harvesting, fire management, and land exchanges. Poaching not only removes individuals from the breeding population, but also may result in permanent habitat loss in some cases, if rocks are pried apart and fallen wood is shredded. Firewood harvesting, fire management, and collection of fallen wood removes the ground debris that is a limiting habitat requirement for this species.
San Diego mountain kingsnake: Fairly large tracts of suitable habitat occur within the Plan Area. These areas are mostly located adjacent to additional suitable habitat within Orange and San Diego Counties. Nearly all of the areas within the Plan Area will be conserved within the MSHCP Conservation Area. These areas are within the higher elevation Santa Ana Mountains and Palomar Mountains. Very little is known about genetic relationships between San Diego mountain kingsnakes within the species range and within the Plan Area to determine if important genetically distinct and isolated populations occur. However, in order to retain potential genetic variation it is important to conserve representative populations at the limits of the species distribution and range, including latitude, longitude, and elevation. Accordingly, large habitat blocks important to the San Diego mountain kingsnake are distributed within the MSHCP Conservation Area within the following Core Areas: Santa Ana Mountains (Existing Core B plus Existing Core F; 79,850 acres), Agua Tibia Mountains (Existing Core M; 10,460 acres), and Desert Transition (Existing Core L plus Proposed Core 6; 29,040 acres). All of these contain, or are expected to contain, the habitat requirements necessary to support San Diego mountain kingsnake populations.
Implementation of the MSHCP, including the conservation of existing San Diego mountain kingsnake populations and suitable habitat as described above will maintain viable populations of the sub-species. The current population size and local distribution of the sub-species is unknown and censussing populations is very difficult due to steep terrain and habitat preferences of the species. Ensuring that the San Diego mountain kingsnake remains viable in the Plan Area will require a comprehensive management plan. The species is unlikely to be at high risk of extirpation resulting from catastrophic events or demographic or genetic stochasticity resulting from implementation of this plan, due to the intact nature of the suitable criteria area.
San Bernardino mountain kingsnake: Large blocks of suitable habitat occur within the San Bernardino Mountains and San Jacinto Mountains. Within these mountain areas, large areas of suitable habitat exist. These areas are predominantly under the management of the Forest Service or State Parks. The San Bernardino Mountains portion of their range is mostly within San Bernardino County and only marginally ranges into the Plan Area north of Banning. The San Jacinto Mountains portion of the San Bernardino mountain kingsnake range is almost entirely within the Plan Area. Most of the areas within the MSHCP Plan Area will be conserved as reserve and Public/Quasi-Public Land designations. These areas are within the higher elevation San Jacinto and San Bernardino Mountains. Very little is known about genetic relationships between San Bernardino mountain kingsnakes within the species range and within the Plan Area to determine if important genetically distinct and isolated populations occur. However, in order to retain potential genetic variation it is important to conserve representative populations at the limits of the species distribution and range, including latitude, longitude, and elevation. Accordingly, large habitat blocks important to the San Bernardino mountain kingsnake are distributed within the MSHCP Conservation Area within the following Core Areas: San Jacinto Mountains(Existing Core K; 149,750 acres) and San Bernardino Mountains (Existing Core I; 9,610 acres). Both of these contain, or are expected to contain, the habitat requirements necessary to support San Bernardino mountain kingsnake populations.
Implementation of the MSHCP, including the conservation of existing San Bernardino mountain kingsnake populations and suitable habitat as described above will maintain viable populations of the sub-species. The current population size and local distribution of the sub-species is unknown and censussing populations is very difficult due to steep terrain and habitat preferences of the species. Ensuring that the San Bernardino mountain kingsnake remains viable in the Plan Area will require a comprehensive management plan. The species is unlikely to be at high risk of extirpation resulting from catastrophic events or demographic or genetic stochasticity resulting from implementation of this plan, due to the intact nature of the suitable criteria area.
San Diego mountain kingsnake: In summary, conservation for the San Diego mountain kingsnake will be achieved by the inclusion of at least 7,708 acres of suitable Conserved Habitat within 3 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside and San Diego counties.
San Bernardino mountain kingsnake: In summary, conservation for the San Bernardino mountain kingsnake will be achieved by the inclusion of at least 22,159 acres of suitable Conserved Habitat within 2 Core Areas which are composed of large blocks of habitat within the MSHCP Conservation Area. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. Furthermore, the Plan Area is contiguous with suitable habitat in San Bernardino County.
San Diego mountain kingsnake: Approximately 2,723 acres (26 percent) of potential habitat for the San Diego mountain kingsnake would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan.
San Bernardino mountain kingsnake: Approximately 7,571 acres (26 percent) of potential habitat for the San Bernardino mountain kingsnake would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan.
San Diego mountain kingsnake: The MSHCP database holds no records for the San Diego mountain kingsnake. The reason for the lack of data is likely due to a number of factors, including difficulty in accessing extant populations due to inhospitable terrain, species life history characteristic of occurring under cover or in rock outcrops, lack of general survey effort, and species range barely occurring within the MSCHCP Plan Area. A fair amount of information exists in the literature, for Lampropeltis zonata although there is less information specifically regarding the subspecies within the Plan Area. There is no information available regarding survivorship and dispersal, and little information regarding socio-spatial interactions and community relationships. Though there is no point data information for the San Diego mountain kingsnake, the subspecies is tied to elevations between 1,219 and 1,829 m, on relatively steep terrain on land predominantly managed by the U.S. Forest Service, in specific habitats (montane coniferous forests, hardwood forests and narrow riparian bands within canyons), and within the Santa Ana Mountains, Palomar Mountains, and Santa Rosa Mountains. Therefore, the amount of existing information is considered adequate.
San Bernardino mountain kingsnake: The MSHCP data base holds 13 records for the San Bernardino mountain kingsnake between 1926 and 1997 (also includes undated records). Of the 13 records, 1 (8 percent) is precision code "1" (having both and "x" and "y" coordinates); 2 (15 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 10 (77 percent) are precision code "3" or "4" (relatively imprecise locations from general areas). The reason for the paucity of data is likely due to a number of factors, including difficulty in accessing extant populations due to inhospitable terrain, species life history characteristic of occurring under cover or in rock outcrops, lack of general survey effort, and species range barely occurring within the MSHCP Plan Area.
A fair amount of information exists in the literature, for Lampropeltis zonata although there is less information specifically regarding the subspecies within the Plan Area. There is no information available regarding survivorship and dispersal, and little information regarding socio-spatial interactions and community relationships. Though there are few data points for the San Bernardino mountain kingsnake, the subspecies is tied to elevations between 370 and 2,470 m, on relatively steep terrain on land predominantly managed by the U.S. Forest Service, in specific habitats (montane coniferous forests, hardwood forests and narrow riparian bands within canyons), and within the San Jacinto Mountains and San Bernardino Mountains. Therefore, the amount of existing information is considered adequate.
According to Zeiner et al. (1988), L. zonata is found most commonly in the vicinity of rocks or boulders near streams or lake shores, where it may utilize rotting logs and seek cover under dense shrubs throughout its California range. Occurring in a variety of habitats including valley-foothill hardwood, and hardwood-conifer, mixed and montane chaparral, valley-foothill riparian, coniferous forests, and wet meadows (Zeiner et al. 1988). Holland and Goodman (1998) further refine its habitat associations for southern California by characterizing it as a species which is typically found in montane coniferous forests or mixed coniferous forests, occasionally in riparian woodlands at lower elevations. In other areas of California, it may occasionally occur into chaparral communities. Regardless, L. zonata is primarily associated with montane coniferous forests and mixed coniferous forests and secondarily associated with riparian woodland, oak woodland, chaparral, and coastal sage scrub (McGurty 1988). Chaparral and scrub habitats are only occupied when woodland habitats are present nearby (Zweifel 1952; McGurty 1988). L. zonata pulchra and parvirubra are often, but not exclusively, associated with rock outcrops and talus, where they use crevices and cap rocks, or rocks on soil as refugia, basking sites, hibernation sites, foraging grounds, and suitable oviposition sites (Jennings and Hayes 1994; Holland and Goodman 1998). A key habitat feature in many areas appears to be the presence of downed logs, usually of large conifers (Holland and Goodman 1998).
McGurty (1988) found that L. zonata were most commonly found in the following order, (1) under rocks, (2) in rock cracks, under logs or bark of logs and stumps, (3) in the open, and (4) dead on the road.
In the interior mountain ranges, L. z. pulchra occurs primarily in associations of ponderosa, Jeffrey, and Coulter pine, and black oak, and is infrequently found below the coniferous forest associations (Zweifel 1952; McGurty 1988; Jennings and Hayes 1994). When occurring at lower elevations, and in the coastal ranges, it occurs below the edge of mixed oak-coniferous forest in riparian woodlands, usually in canyon bottoms, that have western sycamore, Fremont's cottonwood, coast live oak, willows, wild rose, poison oak, and blackberries. It may be found in narrow riparian woodlands in association with chaparral and coastal sage scrub vegetation types (Zweifel 1952; Jennings and Hayes 1994; McGurty 1988). L. z. pulchra is known to occur in the narrow riparian woodlands in association with chaparral and coastal sage vegetation types (Jennings and Hayes 1994). Most of the L. z. pulchra found by McGurty (1988) in rock outcrops, were associated with open stands of conifers and black oak. Within the rock outcrops, snakes preferred to be under layered rock structures and in rock fractures nearly twice as often as under a rock on the ground. Adults and subadults are more selective than juveniles, choosing rock structures with direct subterranean access while juveniles were mainly found under rocks on ground soils. Rock outcrops within broken shade are preferred, however shady north-facing rocks and rock fissures which are wider than the snake body within the rock outcrop, are usually avoided (McGurty 1988).
L. z. parvirubra occurs in well-illuminated canyons with rocky outcrops or rock talus in association with bigcone spruce and various canyon chaparral species at lower elevations, and with black oak, incense cedar, Jeffrey pine, and ponderosa pine at higher elevations (Zweifel 1952; Jennings and Hayes 1994; McGurty 1988).
L. pyromelana, an Arizona Mountain kingsnake which uses similar habitats, is like many other squamate species in shaded areas, in that it appears to be a thermoconformer to air and substrate temperatures (Bowker 1994; Huey and Slatkin 1976). This appears to be an advantage to the mountain kingsnake in that it is able to persist in the colder higher elevations, and is able to out-compete other snakes which invade the shady canyons inhabited by lower elevation snakes.
Lampropeltis zonata occurs throughout the montane portions of south-central Washington, Oregon, California, and into northern Baja California, Mexico (McGurty 1988) along the Cascade and Sierra Mountains and patchily through the Coast Ranges, Transverse Ranges and patchily down the Peninsular Ranges, effectively circling California's Central Valley. Throughout its range, it may be found from sea level to 2450+ m (Zeiner et al.1988), however Klauber (1943) states that L. zonata is seldom found below an altitude of 4000 feet.
Generally speaking, L. z. pulchra is apparently restricted to Coast Range south of Ventura County and across to the Peninsular Ranges. Specifically, it ranges from the Santa Monica Mountains (Los Angeles County), Santa Ana Mountains (Orange and Riverside Counties), Santa Rosa Mountains (Riverside County), and Corte Madera, Cuyamaca, Hot Springs, Laguna, and Palomar Mountains (San Diego County) (Jennings and Hayes 1984; McGurty 1988). The subspecies has been documented from sea level to approximately 1800 m however, the lower elevational ranges are for coastal situations which enjoy lower temperatures and fog or abundant cloud cover. The inland locations (e.g., Santa Ana Mountains, Santa Rosa Mountains) are more typical and primarily support the subspecies between 1219 and 1829 m (McGurty 1988).
L. z. parvirubra is generally associated with the Transverse Ranges, where it is restricted to the San Gabriel (Los Angeles County), San Bernardino Mountains (Los Angeles and San Bernardino Counties), and San Jacinto Mountains (Riverside County). L. z. parvirubra is documented from elevations ranging from 370 to 2470 m (Jennings and Hayes 1984).
Known populations for L. z. pulchra occur in the Santa Ana Mountians.
Known populations for L. z. parvirubra occur in Idyllwild and south of Banning on the San Jacinto Mountains. The MSHCP data base also has locations within the Santa Rosa Mountains; these are likely to have been misidentified and are actually San Diego mountain kingsnake.
For L. z. pulchra, the key populations include all known locations and suitable habitat (i.e., montane conifer, oak, and hardwood woodlands and forests within the Santa Ana and Santa Rosa Mountains and all riparian woodlands draining through the foothills of these mountains.
Genetics: In 1943, Klauber examined specimens from throughout their range. He concluded that within California, there were two distinct subspecies of L. multicincta (zonata), multicincta and multifasciata. Based on his range and morphological descriptions, L. m(z). multicincta is now recognized as L. z. parvirubra and L. m(z). multifaciata is now recognized as L. z. pulchra. Zweifel (1952), last examined the species with his descriptions of the lampropeltis zonata subspecies. Because DNA or other chemical methods have not been utilized to determine the relationships between the subspecies, we must rely on morphological characters to differentiate between them. Zweifel's diagnosis of Lampropeltis zonata pulchra is that it may be distinguished from the other subspecies by the lack of red on the snout, fewer than 39 body triads (cyclical color bands), first white ring in anterior position, and relatively large amount of red per triad. His diagnosis of Lampropeltis zonata parvirubra is that it may be distinguished by first white ring in anterior position, high triad count (37 or more), snout dark, and relatively little red on body (1952).
Diet and Foraging: L. zonata diet is known to include lizards, lizard eggs, smaller snakes, nestling birds and eggs, and small mammals (Fitch 1936; Cunningham 1959; Zwiefel 1974; Zeiner et al. 1988). The only known naturally caught prey items of L. zonata pulchra are western fence lizards and western skinks (McGurty 1988; Holland and Goodman 1998) however it is likely that other lizards and small mammals are also taken (McGurty 1988, Jennings and Hayes 1994). McGurty (1988) found that captive L. z. pulchra would feed on fence lizards, skinks, side-blotched lizards, and mice. Lampropeltis zonata parvirubra has been documented to consume western fence lizards, skinks, and sagebrush lizards. Newton and Smith (1975) and Jennings and Hayes (1994) both indicate that these subspecies are primarily saurophagous.
Daily Activity: Lampropeltis zonata is normally diurnally and crepuscularly active from mid-March to mid-October at lower elevations with a reduced period at higher elevations (Newton and Smith 1975; Zeiner et al. 1988; Holland and Goodman 1998). McGurty (1988) found that L. z. pulchra was active diurnally from March through November with a peak in activity from mid-April to mid-May. Both L. z. pulchra and L. z. parvirubra have been found to be active nocturnally during the warmest periods in late spring and summer (Stebbins 1954; Newton and Smith 1975; McGurty 1988). Bowker (1994) found that Sonoran Mountain kingsnakes (Lampropeltis pyromelana) were most active between 1500 and 1600 hours.
Reproduction: L. zonata is oviparaous (Holland and Goodman 1998). The time of reproduction is thought to be correlated with winter hibernation and heat (McGurty 1988). McGurty (1988) hypothesized that these factors are synchronized with endogenous circannual rhythms and result in mating behavior and oviposition around the same time each year (Duvall et al. 1982). Males are combative upon emergence from hibernation to establish the dominant breeding individual (McGurty 1988) whereupon, the dominant, usually larger snake, breeds significantly more than the subordinate snakes (McGurty 1988). The breeding males ascertain the females reproductive condition through olfactory cues (McGurty 1988). McGurty (1988) found that females must be at least 600 mm snout-vent length (an estimated four or five years old) to reproduce.
Mating occurs from March or April (Newton and Smith 1975) to May (Zeiner et al. 1988). In captive L. z. pulchra, mating occurs in May and eggs are laid in June or early July (McGurty 1988; Jennings and Hayes 1994). The female L. zonata is known to lay a clutch of eggs in July (Newton and Smith 1975), however L. z. parvirubra is known to have laid eggs in mid-July (Cunningham 1959a). It is likely that L. z. pulchra is comparable.
Female L. zonata lay a single clutch of 3-8 eggs (Nussbaum et al. 1983; Holland and Goodman 1998), with clutch size ranging from 4 to 12, but the most common clutch sizes are 5 or 6 eggs (Zeiner et al. 1988). Eggs are probably laid in loose well-aerated soil under rocks, other surface objects, or decaying logs (Zeiner et al. 1988). Newton and Smith (1975) state that about five eggs are laid in decomposing wood or moist soil (Newton and Smith 1975). Cunningham (1959) noted that a single L. z. parvirubra laid 3 eggs and Zweifel (1952) and Jennings and Hayes (1994) indicate that L. z. parvirubra is known to hatch up to 8 young, although the original clutch size is unknown.
In Lampropeltis zonata, eggs hatch in about 63 days (Newton and Smith 1975), usually occurring from late June to early October (Zeiner et al. 1988). However, for L. z. pulchra in captivity, hatching occurs after 54-87 days (McGurty 1988), requiring at least two months (Jennings and Hayes 1994).
L. z. pulchra hatch between late August and early October (Jennings and Hayes 1994). Hatchlings measure between 200-2500 mm snout-vent length (McGurty 1988; Holland and Goodman 1998).
Survival: There is no information in the literature regarding survivorship in the field. Likewise, there is no data on longevity in the field.
Dispersal: There is no information regarding dispersal in the literature; however, McGurty (1988), Jennings and Hayes (1994), and Holland and Goodman (1998) all discuss the subspecies' site tenacity and even microsite tenacity. McGurty (1988) found that some individuals could be found at the same rock outcrops for multiple years and of those, some individuals could be found under the same rock. McGurty proposes that perhaps they do not leave the natal rock outcrop.
Socio-Spatial Behavior: The only territorial discussion in the literature applies to competition for reproductive status (McGurty 1988). There is no other literature discussing interactions between conspecifics.
Community Relationships: Little is known of their community relationships. Zeiner et al. (1988) believe that adults and juveniles are probably preyed upon by hawks, owls, and medium and large-sized mammals and that egg clutches may be taken by medium-sized mammals. Duncan (1992) found that the Sonoran Mountain kingsnake accounted for a small fraction of the prey species for the Mexican spotted owl in Arizona and New Mexico. According to Newton and Smith (1975), they probably face little competition because they occupy cooler habitats which generally exclude other snake species.
A number of factors affect these two subspecies including: over-collecting, destruction of habitat by collectors, firewood harvesting, logging, and development (Newton and Smith 1975; McGurty 1988; Zeiner et al. 1988; Jennings and Hayes 1994; Holland and Goodman 1998).
Both subspecies, within the Plan Area, are generally restricted to rock outcrops and talus structures within montane conifer habitats, montane hardwood habitats, and steep and shady riparian woodland habitats at lower elevations and contiguous to higher elevations. Within the rock outcrops, they only use select portions which satisfy their thermoregulation and foraging requirements, sometimes staying at the same outcrop or returning to the same rock over a period of years. It has been suggested that they might even stay at their natal rock outcrop. L. z. pulchra is only known from the Santa Ana Mountains and Santa Rosa Mountains, at the westernmost portion of the Plan Area, while L. z. parvirubra is only known from the San Jacinto Mountains in the Plan Area. The relatively long-lived snake, takes longer to become reproductively active than comparatively normal, and produces relatively few eggs (4 on average).
The U.S. Forest Service Four-Forest Management Plan will do a great deal to protect these subspecies once it is approved and implemented. However, strict control over poachers is necessary, and protection of known locations is necessary.
Bowker, R.W. 1994. Serpentes: Lampropeltis pyromelana (Sonoran Mountain kingsnake): Temperature, activity, and size. Herpetological Review. 25:124-125.
Cunningham, J.D. 1959a. Reproduction and food of some California snakes. Herpetologica. 15(1):17-19.
Duncan, R.B. 1992. Lampropeltis pyromelana (Sonoran Mountain kingsnake). Predation. Herpetological Review 23(3):81.
Duvall, D., L.J.Guilette Jr., and R.E. Jones. 1982. Environmental control of reptilian reproductive cycles. In C. Gans and H. Pough (eds.). Biology of the Reptilia.
Fitch, H.S. 1936. Amphibians and reptile of the Rogue River Basin, Oregon. American Midland Naturalist. 17(3):634-652.
Holland, D.C., R.H. Goodman. 1998. A guide to the amphibians and reptiles of MCB Camp Pendleton, San Diego County, California. Prepared for AC/S Environmental Security Resource Management Division MCB Camp Pendleton, CA. Contract M00681-94-C-0039.
Huey and Slatkin. 1976. Quart. Rev. Biol. 51:363-384
Jennings, M.R., M.P. Hayes. 1994. Amphibian and reptile Species of Special Concern in California. Calif. Dept. of Fish and Game Spec. Publ.
Klauber, L.M. 1943. The coral king snakes of the Pacific coast. Trans. San Diego Nat. Hist. Soc. 10:75-82.
McGurty, B.M. 1988. Natural history of the California Mountain kingsnake. In:DeLisle, H.F., P.R. Brown, B. Kaufman and B.M. McGurty (eds). Proc. Conf. Calif. Herpetol. Spec. Publ. SW Herpetologists Society.
Newton, M.S., R. Smith. 1975. The snake that lost its habitat. Natural History. 84(6):72-77.
Nussbaum, R.A., E.D. Brodie, Jr. and R.M. Storm. 1983. Amphibians and reptiles of the Pacific northwest. Univ. Idaho Press, Moscow, Idaho.
Stebbins, R.C. 1954. Amphibians and Reptiles of western North America. McGraw-Hill, New York. 536pp.
Zeiner, D.C., W.F. Laudenslayer, Jr., and K.E. Mayer. 1988. California's wildlife. Volume I. Amphibians and reptiles. California Statewide Wildlife Habitat Relationships System, California Department of Fish and Game, Sacramento, California.
southern rubber boa (Charina bottae umbratica)
State: Threatened
Federal: Sensitive (USFWS)
The southern rubber boa population is narrowly defined within the San Jacinto Mountains. The rubber boa is often found in fallen debris, rock piles, and steep, rocky montane areas within coniferous forests, woodlands, chaparral, and grasslands above 1,540 meters in elevation. It is assumed that this species will respond to a landscape level of management with site-specific requirements (i.e., fallen debris, rock piles) if management addresses the threats of development, firewood harvesting, poaching, off-road vehicle use, fern harvesting, commercial timber harvesting, fire management, and land exchanges.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 2,577 acres of chaparral, grassland, montane coniferous forest, deciduous woodlands, and forest above 1,540 meters in elevation within the Plan Area. Conserved habitat will include both linkages between conserved areas and the fallen debris and rock piles that are a limiting habitat feature for this species. Habitat conserved for this species will be limited to large blocks within the San Jacinto Mountains.
For purposes of this conservation analysis, suitable habitat for this species includes all montane wooded habitats and interspersed chaparral and grassland habitats above 1,540 m in the San Jacinto Mountains (San Jacinto Mountains Bioregion). Acreages for these habitats within the Plan Area have been combined within three categories (Woodlands and Forests; Riparian Scrub, Woodland, and Forest; and Montane Coniferous Forest) and are provided in Table 1 below. Due to the paucity of data points (see below), species conservation can not be based on species occurrence preservation. Instead, conservation must be based on habitat preservation within the San Jacinto Mountains, as directed by historical information, anecdotal information, and various monitoring and maintenance activities as outlined below.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
SOUTHERN RUBBER BOA
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 2,237 | 0 | 2,089 | 2,089 | 46 | 101 | 147 |
| Grassland | 1 | 0 | 1 | 1 | 0 | 0 | 0 |
| Montane Coniferous Forest | 117 | 0 | 111 | 111 | 4 | 2 | 6 |
| Riparian Scrub, Woodland and Forest | 15 | 0 | 15 | 15 | 0 | 0 | 0 |
| Woodlands and Forest | 359 | 0 | 357 | 357 | 1 | 1 | 2 |
| TOTAL | 2,729 | 0 | 2,577 | 2,577 | 51 | 104 | 155 |
| 1 Total acres include habitat above 1,500 m within the San Jacinto Mountains. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
Based on these habitats, the San Jacinto Mountains Bioregion supports approximately 2,729 acres of potential habitat for the southern rubber boa within the Plan Area. Approximately 2,577 acres (95 percent) of the suitable habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the southern rubber boa. Management actions will be incorporated into the conservation strategy so that habitat conditions will be maintained.
As described below under Data Characterization, data points are considered too few and too old, therefore preservation based on species occurrence is not feasible. All data points and known locations are situated within Forest Service lands or in the vicinity of Forest Service lands. The known limits of the population occur within the U.S. Forest Service San Jacinto Wilderness (approximately 4,100 acres) and San Jacinto Management Area (approximately 40,000 acres; includes roadless areas around Rouse Hill and Horse Creek Ridge and portions of the Rouse and Garner Range Allotments). Although a review of elevational and habitat data indicate that suitable areas also occur on the Soboba Management Area, Mount San Jacinto Wilderness State Park, Garner Management Area (mostly covered by the Garner and Wellman Range Allotments), Pyramid Management Area (Partially covered by the Pyramid Peak A Roadless Area and entirely covered by the Wellman Range Allotment), and Bautista Management Area (area is dominated by roadless areas on Rouse Hill, Hixon Flat, and Cahuilla Mountain; and is approximately half covered by the Rouse Range Allotment).
Conservation of the southern rubber boa has been considered from a landscape perspective because the species may be found throughout the San Jacinto Mountains in suitable habitat, and conservation based on species occurrence is not feasible due to paucity of data. To ensure the persistence of this species in perpetuity, the Forest Service will also need to address development, poaching, firewood harvesting, off-road vehicle use, fern harvesting, commercial timber harvesting, fire management, and land exchanges to manage discussed threats to the species. Firewood harvesting, fire management, and collection of fallen wood remove the ground debris that is a limiting habitat requirement for this species. Poaching not only removes individuals from the potential breeding population, but may also result in permanent habitat loss in some cases if rock fissures are pried apart and fallen wood is displaced. Off-road vehicle use has been documented to occur in areas occupied by the southern rubber boa, resulting in the destruction of ground cover and riparian areas, and compaction of soils (Stewart 1991). F ern collecting typically occurs during critical post-hibernation seasons.
Only one large contiguous block of habitat supporting the southern rubber boa is present within the MSHCP Plan Area, and it will be conserved as Public/Quasi-Public Land designation. This area is located on the San Jacinto Mountains (Existing Core K; 149,750 acres), primarily on U.S. Forest Service land. Protection is provided by the Forest Service. Because it is unknown what decisions are made by the rubber boa, when moving between seasonal habitats, protection of a wide range of microhabitats within the block will be necessary. Very little is known about genetic relationships between rubber boas within the species range and within the Plan Area in order to retain important genetic variation, it is important to conserve representative populations at the limits of the species distribution and range, including longitude, latitude, and elevation. To this end, the Plan Area contains a relatively large and contiguous area with a wide elevational range within habitat that is suitable for the species.
Implementation of the MSHCP, including the conservation of the existing population and suitable habitat as described above, will maintain viable populations of the southern rubber boa. The current population size and local distribution of the southern rubber boa is unknown and censussing populations is very difficult due to steep terrain secretive nature, and habitat preferences of the species. Ensuring that the species remains viable in the MSHCP Plan Area will require a comprehensive management plan and general monitoring as described below.
In summary, conservation for the southern rubber boa will be achieved by the inclusion of at least 2,577 acres of suitable Conserved Habitat within one Core Area (San Jacinto Mountains) within the MSHCP Conservation Area. The Core Area provides connections between seasonally preferred habitats. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size and distribution of the southern rubber boa is unknown. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, and San Diego counties.
Incidental Take of the southern rubber boa is difficult to quantify due to our limited knowledge of the species distribution within the Plan Area and the fact that losses may be masked by fluctuations in abundance and distribution during the life of the permit. However, the maximum level of Take of the southern rubber boa can be anticipated by the loss of the number of acres of habitat that will become unsuitable for this species, and individuals within these areas will be subject to Incidental Take consistent with the Plan. Approximately 155 acres (5 percent) of potential habitat for the southern rubber boa would be outside the MSHCP Conservation Area.
The MSHCP data base holds 4 records for the southern rubber boa between 1929 and 1987 (also includes an undated record). Of the 4 records, 1 (25 percent) is precision code "2" (one "x" or"y" or equivalent); and the remaining 3 (75 percent) are precision code "3" or "4" (relatively imprecise locations from general areas). All of the dated records are either old 3 (75 percent) or undated 1 (25 percent). Also, Stewart (1988) indicates that there are five other locations within the San Jacinto Mountains. These locations were not verified by the MSHCP data base. The reason for the paucity of data is likely due to a number of factors, including difficulty in accessing extant populations due to inhospitable terrain, species life history characteristic of occurring under cover or in rock outcrops, and lack of general survey effort. Few studies exist which specifically examine the C. b. umbratica subspecies. Most studies are directed to C. bottae. Important information which is lacking includes movement, dispersal, home range, migration, microhabitat requirements, among other data. Though there is an apparent paucity of point data and specific life history information, the subspecies is tied to high elevations in relatively steep terrain on land predominantly managed by the U.S. Forest Service.
Regardless of data point age (or lack thereof) and paucity of data points, it is obvious that all records were situated around the San Jacinto Mountains. Based on the historic data record and anecdotal observations, there is a single "key" population in the Plan Area, which is situated on Mount San Jacinto. Specifically, on montane slopes and drainages above 1,540 m. Therefore, the amount of existing information is considered adequate.
In general, the southern rubber boa inhabits moist coniferous forests and woodland habitats (Stewart 1988) which may be interspersed with large grassy fields or other open areas (Hoyer 1977). Stebbins (1985) indicates that they frequent areas dominated by grassland, broken chaparral, woodland, and forest, in and beneath logs, rock, and bark. According to Stewart (1988) prime habitat is dominated by Jeffrey pine (Pinus jeffreyi), yellow pine (Pinus ponderosa), sugar pine (Pinus lambertiana), white fir (Abies concolor), incense cedar (Callocedrus decurrens), and black oak (Quercus kelloggii). During warmer weather, cooler and wetter riparian and forested areas become more important. In the spring, areas which contain rock outcrops with a southern exposure and with scattered surface rocks are a particularly significant habitat feature in forested and relatively open sites (Stewart 1991). Rock outcrops serve as hibernacula. Snags, logs, and other surface debris provide cover (Zeiner, et al. 1988).
The southern rubber boa is restricted to the San Gabriel, San Bernardino and San Jacinto Mountains (Erwin 1974; Stebbins 1985; Zeiner, et al. 1988) in southern California. Individuals identified within the La Panza Range, Tehachapi Mountains and Mount Pinos area may be integrades (Stewart 1988). According to Stebbins (1985) the subspecies is found from sea level to around 10,000 feet, however Stewart (1988) determined that they range between 5,051 feet (1540m) and 8,069 feet (2460m) in elevation. Fisher and Case (1997) indicate that they occur at elevations above 2,000 meters in the San Jacinto and San Bernardino Mountains.
When the sub-species was listed (1971), it was only known from 10 localities in San Bernardino and San Jacinto Mountains (Stewart 1988). As of Stewart's 1988 paper, only eight localities were known from the San Jacinto Mountains. The southern rubber boa has been found within the transition life zone in the San Jacinto Mountains; known from Fern Valley near Idyllwild (Glaser 1970). Historic occurrences include the following: Suicide Peak Trail ca. 1.5 miles north of Idyllwild; Marion Mountain, near Idyllwild; Humber Park near start of Devil's Slide Trail; Devil's Slide Trail, ca. one mile above Humber Park; Devil's Slide Trail, ca. 2.5 miles above Humber Park toward Tahquitz Valley; between 5,000 and 8,000 feet (Stewart 1991). The bulk of the known San Jacinto population is in designated wilderness (Loe 1985). However, several locations occur on private land inholdings.
Humber Park, Idyllwild, Sage, and San Jacinto Mountains.
Genetics: A clear and concise review of rubber boa systematic history is presented by Stewart (1988) and synopsized here. In 1890, Stejneger described the genus Charina, including in it three species. Later these were condensed into one species, C. bottae (Stejneger and Barbour 1923). In 1943, Klauber described C. b. umbratica and was validated by Cunningham (1966) and Erwin (1974) who suggested elevating C. b. umbratica to a full species. Klauber's description held until 1974 (Nussboum and Hoyer) when they concluded that all were the same species. Stewart (1977) found that the subspecies C. b. umbratica was justified. Furthermore, he found that isolated populations between the C. b. bottae and C. b. umbratica (Tehachapi Mountains and Mount Pinos) exhibited characteristics of both subspecies and may be integrades. Stewart states that "one of my graduate students presently is assembling all of the morphological data we have and running electrophoretic analysis on tissue samples from different populations...," though I have not been able to locate it.
Diet and Foraging: While little information is available for the southern rubber boa sub-species, some information exists for the species in general. The species eats small mammals (moles, mice and shrews), birds, salamanders, lizards, snakes, and insects (Stebbins 1985; Shaw and Campbell 1974; Brown 1974; Linder 1963; Macey 1983; Zeiner, et al. 1988). Rodriguez-Robles, et al. (1999) found that mammals, lizards, birds, and squamate eggs composed 66 percent, 17 percent, 7 percent, and 5 percent respectively, of the prey of C. bottae. Smaller animals fed on lizards and squamate eggs, while larger animals added mammals and birds to their diet and stopped taking squamate eggs. Additionally, they found that most of the snakes with multiple prey had injected nestling birds or mammals and that multiple-prey eaters were not significantly larger than those with single prey. Insect may be an important food resource for young rubber boas (Stewart 1988). Large prey items are usually killed by constriction before swallowing (Stewart 1988). Dorcas et al (1997a) studied the digestive and passage rate for C. bottae from 10 degree Celsius to 35 degrees Celsius. They found that temperature did not seem to affect digestive rate, but thermoregulating digesting snakes passed food 12 percent faster than those thermoregulating as non-digesting snakes.
Daily Activity: Stewart (1988) characterizes the species as primarily crepuscular or nocturnal in its activity, although it may move about the surface on overcast days. Campbell and Shaw (1974) found that the body temperature of active rubber boas may be 12 degrees Celsius and that their critical thermal maximum temperature is 38 degrees Celsius, however Dorcas et al (1997b) found their thermal preference to be 27.4 degrees Celsius. Dorcas et al (1998) measured body temperature variation in free-ranging C. bottae by surgically implanting temperature transmitters into 14 females. The females were monitored at 5-minute intervals for periods up to a year. They found that snakes were nocturnally active, at low temperatures (14 degrees Celsius) approximately every eight days; pregnant snakes maintain higher and less variable body temperatures than non-pregnant snakes; the thermal; environment prevented snakes from maintaining high, stable body temperatures; and, when unconstrained by the thermal environment, the snakes did not maintain a high, stable body temperature with regularity. Rubber boas appear to maintain their head temperature within more narrow limits than their body (Dorcas et al 1997b). Dorcas, et al. (1997b) found that rubber boas maintained warmer heads at average body temperatures below their thermal preference (27.4 degrees Celsius) and cooler heads at average body temperatures above their thermal preference.
Reproduction: Breeding usually occurs between April and June (Zeiner, et. al. 1988). The rubber boa bears 2-8 live young between August (Erwin 1964) through November (Hudson 1957; Stebbins 1985). Females are thought to only bear young every two to three years (Stewart 1988).
Survival: No information is available.
Dispersal: Hoyer (in Stewart 1988) found that the species was easier to collect during the spring, late summer, and early fall which may be the times when they are more likely to be dispersing. The only quantified movement for a southern rubber boa over a season is 300 yards (Loe 1985). It is possible that southern rubber boas may migrate short distances between suitable hibernacula and summertime activity sites (Zeiner 1988).
Socio-Spatial Behavior: This species has been described as secretive and very difficult to observe (Stewart 1991). During the summer or fall, the rubber boa may be on or near the surface during periods of high humidity or rain, and appear to be more collectable (active) during the spring, late summer, and early fall (Stewart 1988). Southern rubber boas apparently prefer rock outcrops with a southern exposure and scattered surface rocks in the early spring. When the weather warms and becomes drier, rubber boas move into cooler and moister habitats (Stewart 1988). The species may utilize rock crevices to bask in the threads of sunlight.
Community Relationships: Rubber boas may hibernate with other snakes, including kingsnakes and rattlesnakes. The species utilizes a specialized defensive posture when attacked by covering the head with body coils and presenting the tail to attackers (Hoyer 1974). This is presumably effective because the tail and head are both shaped alike. Known predators of rubber boas include hawks, owls, skunks, and raccoons (Zeiner, et al. 1988). The rubber boa may compete for food resources with the California Mountain kingsnake (Zeiner, et al. 1988).
The most serious and pervasive activities to impact this taxon are development associated with ski resort expansion and new dwellings (Stewart 1988). However, firewood harvesting, off-highway vehicle use, fern harvesting, commercial timber harvesting, fire management, skiing (recreation), and federal/private land exchanges are also of great concern (Stewart 1991). All of these factors contribute to habitat loss and fragmentation, isolation of populations, and the increased probability of local extirpations (Stewart 1991). Fern picking in the spring occurs at the same time that boas are coming out of hibernation. Up to 50-60 percent of habitat could be lost to development of private land, firewood harvesting, and OHV use in the next 20-40 years (Stewart 1991). Conversion of burned forest to shrubby vegetation, and loss of downed logs due to fire management practices (Southern Rubber Boa Advisory Committee 1986) is also contributing to decline.
This species tends to occur in isolated populations with areas of apparently suitable, but unoccupied habitat intervening (Stewart 1988). Although there is little or no information about movement patterns and dispersal, it is likely that the intervening areas between metapopulations are important for gene flow. It is possible that the intervening areas provide required habitat during different seasons or for different cohorts. Therefore, intervening areas should also be conserved. The only land specifically set aside for conservation of this taxon is a 40 acre site called Heaps Peak Arboretum, in San Bernardino County. The population in Riverside County is geographically isolated and occurs mostly in designated wilderness.
According to Stebbins (1985), the southern rubber boa is a good swimmer, burrower, and climber. However, Stewart characterizes the species as sluggish, essentially fossorial, and primarily crepuscular or nocturnal in its activity, although it may move about the surface on overcast days. The boa's crepuscular or nocturnal movements may lead it to paved roads to absorb heat. The species may utilize rock crevices to bask in the threads of sunlight. This species eats small mammals (mice and shrews), birds, salamanders, lizards, snakes, and insects (Stebbins 1985; Shaw and Campbell 1974; Brown 1974). Large prey items are usually killed by constriction before swallowing (Stewart 1988). Breeding usually occurs between April and June (Zeiner, et al. 1988). The rubber boa bears 2-8 live young between August (Erwin 1964) through November (Hudson 1957; Stebbins 1985). Females are thought to only bear young every two to three years (Stewart 1988). Hoyer (in Stewart 1988) found that the species was easier to collect during the spring, late summer, and early fall. Hibernate with other snakes, including kingsnakes and rattlesnakes. Secretive and very difficult to observe (Stewart 1991). Known to cover head with body coils and present tail to attackers (Hoyer 1974).
Brown, V. 1974. Reptiles and amphibians of the west. Naturegraph Publishers, Happy Camp, California. pp. 79.
Cunningham, J.D. 1966. Observations on the taxonomy and natural history of the rubber boa, Charina bottae. Southwestern Naturalist 11:298-299.
Dorcas, M.E., C.R. Preston and M.E. Flint. 1997a. The thermal biology of digestion in rubber boas (Charina bottae): Physiology, behavior, and environmental constraints. Physiological Zoology 70:292-300.
Dorcas, M.E. and C.R. Preston. 1997b. Head-body temperature differences in free-ranging rubber boas. Journal of Herpetology 31:87-93.
___________. 1998. Daily body temperature variation in free-ranging rubber boas. Herpetologica 54:88-100.
Erwin, D.B. 1974. Taxonomic status of the southern rubber boa, Charina bottae. Copeia 1974:996-997.
Fisher, R.N., and T. J. Case. 1997. A field guide to the reptiles and amphibians of coastal southern California. Lazer Touch, San Mateo, California. Pp. 46.
Glaser, H. S. R. 1970. The distribution of amphibians and reptiles in Riverside, California. Riverside Museum Press, Riverside, California. Pp. 19.
Hoyer, R. F. 1974. Description of a rubber boa (Charina bottae) population from western Oregon. Herpetologica 30:275-283.
Hudson, G.E. 1957. Late paturation in the rubber snake. Copeia 1957:51-52.
Klauber, L.M. 1943. The subspecies of the rubber snake, Charina. Transactions of the San Diego Society of Natural History. pp. 83-90.
Linder, A.D. 1963. Ophiophagy by the rubber boa. Herpetologica 19:143.
Loe, S. A. 1985. Habitat management guide for southern rubber boa (Charina bottae umbricata) on the San Bernardino National Forest. U.S. Department of Agriculture, San Bernardino National Forest, San Bernardino, California. 9 pp. and 1 map.
Macey, R.J. 1983. Charina bottae bottae food. Herpetologic Review 14:19.
Nussbaum, R.A. and R.F. Hoyer. 1974. Geographic variation and the validity of subspecies in the rubber boa, Charina bottae. Northwest Science 48:219-229.
Rodriguez-Robles, J.A., C.J. Bell and H.W. Greene. 1999. Gape size and evolution of diet in snakes: Feeding ecology of erycine boas. Journal of Zoology 248:49-58.
Shaw, C.E. and S. Campbell. 1974. Snakes of the American west. Alfred A. Knopf, New York. xii+330 pp.
Southern Rubber Boa Advisory Committee. 1986. Report, dated September 22, 1986, to San Bernardino National Forest on the committees review of the ""Habitat Management Plan for Southern Rubber Boa."" G. R. Stewart, Chair. California Polytechnic University, Pomona.
Stebbins, R. C. 1985. A field guide to western reptiles and amphibians. Houghton Mifflin, Boston. Pp. 123-124.
Stejneger, L. 1890. On the snakes of the Genus Charina. Proceedings of the U.S. National Museum, Volume 13. Pp.177-182.
Stejneger, L. and T. Barbour. 1923. A check list of North American amphibians and reptiles. 2nd edition. Harvard University Press, Cambridge, MA. 125 pp.
Stewart, G.R. 1977. Charina bottae. Catalogue of American Amphibians and Reptiles. pp.205
________ 1988. The rubber boa (Charina bottae) in California, with particular reference to southern subspecies, C. b. umbratica. In Proceedings of the Conference on California Herpetology, H. F. De Lisle, P. R. Brown, B. Kaufman, and B. M. McGurty (editors). Southwest Herpetological Society. Pp. 131-138.
________ 1991. Status of the southern rubber boa (Charina bottae umbricata) in the San Bernardino Mountains of southern California. Contract report and locality map submitted to the U. S. Fish and Wildlife Service, Laguna Niguel Field Office (now Carlsbad Field Office), Laguna Niguel, California. Pp. 32.
Zeiner, D.C., W.F. Laudenslayer, and K.E. Mayer. 1988. California''s Wildlife: Volume 1 Amphibians and Reptiles. California Statewide Habitat Relationships System. pp. 272
southern sagebrush lizard (Sceloporous graciosus vandenburgianus)
State: Species of Special Concern
Federal: None
For purposes of this analysis, the southern sagebrush lizard population is found within the San Jacinto and Santa Rosa Mountains above 5,000 feet. The sagebrush lizard occurs primarily in open montane areas with good light and scattered low bushes. Habitats in which it is found includes montane chaparral, sage brush, hardwood and conifer forests and woodlands and juniper woodlands. It is anticipated that this species will respond to a landscape level of management with site-specific requirements (i.e., fallen debris and rock piles) if management addresses the threats of catastrophic fire, off-road vehicle usage, road construction, and habitat destruction.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 41,105 acres of chaparral, coastal sage scrub, desert sage scrub, montane coniferous forest, peninsular juniper woodland, and woodlands and forest habitats above 1,500 meters in elevation in the San Jacinto and Santa Rosa Mountains bioregions. Conserved habitat will include both linkages between conserved areas and the fallen debris and rock piles that are a limiting habitat feature for this species. Habitat conserved for this species will be limited to large blocks within the San Jacinto Mountains.
Include within the MSHCP Conservation Area suitable microhabitat sites (e.g., fallen debris and rock piles) within the general habitats.
For purposes of this conservation analysis, potential habitat for the southern sagebrush lizard includes high elevation (1,500 m or higher) chaparral, coastal sage scrub, juniper woodlands, montane coniferous forests, and woodlands and forests within the Plan Area. Based on these habitats, the Plan Area supports approximately 51,354 acres of potential habitat for the sagebrush lizard. Table 1 shows the conservation of potential habitat for the southern sagebrush lizard. Approximately 41,105 acres (80 percent) of the potential habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the southern sagebrush lizard. Management actions will be incorporated into the Conservation Strategy so that habitat conditions will be maintained.
The known limits of the population occur mostly within U.S. Forest Service managed areas including the Soboba Management Area (approximately 25,000 acres), San Jacinto Wilderness Area (approximately 350 acres), San Jacinto State Park (approximately 4,100 acres), San Jacinto Wilderness (approximately 6,600 acres), San Jacinto Management area (approximately 40,000 acres), Garner Management Area (approximately 17,500 acres), Pyramid Management Area (approximately 5,000 acres), and Bautista Management Area (approximately 33,500 acres). These Management Areas, parks, and Wilderness Areas include the Horse Creek Ridge, Rouse Hill, Hixon Flat, Cahuilla Mountain, Pyramid Peak A, and Pyramid Peak B Roadless Areas, and the Rouse, Garner, Paradise, and Wellman Range Allotments.
TABLE 1
SUMMARY OF HABITAT CONSERVATION
SOUTHERN SAGEBRUSH LIZARD
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 21,979 | 0 | 19,288 | 19,288 | 0 | 2,690 | 2,690 |
| Coastal Sage Scrub | 161 | 0 | 150 | 150 | 0 | 10 | 10 |
| Desert Scrubs | 7 | 0 | 7 | 7 | 0 | 0 | 0 |
| Montane Coniferous Forest | 21,420 | 0 | 14,666 | 14,666 | 0 | 6,753 | 6,753 |
| Peninsular Juniper Woodland and Scrub | 13 | 0 | 13 | 13 | 0 | 0 | 0 |
| Woodlands and Forest | 7,774 | 0 | 6,981 | 6,981 | 0 | 793 | 793 |
| TOTAL | 51,354 | 0 | 41,105 | 41,105 | 0 | 10,246 | 10,246 |
| 1 Total acres includes habitats above 1,500 m in the San Jacinto and Santa Rosa Mountains. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
As described below under Data Characterization, 26 of the 42 records have a precision of "1" or "2." Of these 26 records, 15 (58 percent) would be within the MSHCP Conservation Area. Conservation of this species should be considered from a landscape perspective within the parameters of its life history (e.g., elevational restrictions). The percentage of conserved species does not represent the limits of the species range within the Plan Area. The key populations on the San Jacinto Mountains and San Jacinto foothills, as well as other habitat, would be managed mostly by the U.S. Forest Service.
The main large contiguous block of habitat supporting the southern sagebrush lizard will be conserved as reserve and public/quasi-public land designations. This area is primarily located in the San Jacinto Mountains, on U.S. Forest Service land. Coverage is dependant on management commitments from the Forest Service. Private inholdings will not be managed. While debate lingers regarding the potential negative and positive affects that grazing has on sagebrush lizard habitat quality, higher elevation Range Allotments may provide acceptable habitat for the lizard. While debated by the USFWS (2002) due to age and different sub-species focus, Woodbury and Woodbury (1945) thought that grazed areas might provide the appropriate microhabitat conditions which are most utilized by sagebrush lizards (i.e., open areas with low brush and exposed roots caused by erosion or other perturbance). However, grazing may also have negative side-effects by crushing less mobile lizards or egg clutches.
Very little is known about genetic relationships between sagebrush lizards within the species range and within the Plan Area. In order to retain potential genetic variation, it is important to conserve representative populations at the limits of the species distribution and range, including longitude, latitude, and elevation. To this end, the MSHCP Conservation Area contains a relatively large and s conserved area with a wide range of elevational levels within habitat that is suitable for the species. The conserved habitats include the following areas: San Jacinto Mountains (Existing Core K; 149,750 acres) and Santa Rosa Mountains (eastern end of Existing Core L; approximately 10,000 acres).
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the sagebrush lizard. The current population size and distribution is unknown and estimating population densities is labor intensive. Sagebrush lizards are fairly obvious in the landscape, and use ground and shrub resources.
The species is unlikely to be at high risk of extirpation resulting from catastrophic events or demographic or genetic stochasticity due to the intact nature of suitable habitat within the criteria area.
In summary, conservation for the southern sagebrush lizard will be achieved by the inclusion of at least 41,105 acres of suitable Conserved Habitat within the San Jacinto and Santa Rosa Mountains above 1,500 meters. In addition, the MSHCP Plan will maintain (once every 8 years) the continued use of 75 percent of the Core Areas. The current population size and distribution of the sagebrush lizard is unknown, but key habitat areas are known. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, and San Diego counties.
Approximately 10,246 acres (20 percent) of potential habitat for the sagebrush lizard would be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan. Eleven (42 percent) of the 26 precision code "1" or "2" records would be outside the MSHCP Conservation Area.
The MSHCP data base includes 42 records for the southern sagebrush lizard between 1999 and 1908. Of the 42 records, 10 (24 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 16 (38 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 16 (38 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). Only a small number of the precision code "1" or "2" records are relatively recent, with 3 (7 percent) since 1990 and 39 (93 percent) pre-dating 1990 or with no associated date. The reason for the lack of more recent locations is likely due to a lack of survey effort due to perceived lack of sensitivity, large historical data base dating to the early 1900's, lack of reporting, and possibly confusion with the more common western fence lizard (Sceloporus occidentalis). Abundant literature is available as noted in Censky (1986); however, these were not available for this document. It appears that additional information is needed on the microhabitat needs, dispersal methods, connectedness of population, and survivorship of the species, but there is enough information to determine conservation.
The records are generally localized within the eastern portion of the Plan Area. They generally occur within higher elevational areas in association with the eastern mountain ranges. Definable "key" or "core" populations occur on the San Jacinto Mountains and San Jacinto foothills.
S. g. vandenburgianus is widely distributed in montane chaparral, hardwood and conifer habitats, juniper habitats, and sage scrub habitats at higher elevations (Zeiner, et al. 1988). Additionally, manzanita-ceanothus chaparral, pinon-juniper woodland, pine and fir forests are also discussed by Stebbins (1985). Noted similarity of general habitat preferences by S. g. graciosus is apparent and suggests that all subspecies may have similar preferences and life histories. S. g. graciosus occupies high country sage brush, juniper woodlands, conifer forests, and hardwood groves (Woodbury and Woodbury 1945), and though the dominant plant species differ, the structure and general habitat type is consistent.
Stebbins (1985) notes that the preferred micro-habitat features of S. g. vandenburgianus include open ground, good light and scattered low bushes, and is usually found near bushes, brush heaps, logs, or rocks. Woodbury and Woodbury (1945) found that S. g. graciosus was most commonly found among a stand of hardwood with little to no herbaceous ground cover (caused by over grazing) and considerable erosion-exposed tree roots (Note: the USFWS [2002] has expressed concerns regarding the attribution of over-grazing to habitat quality for this species, questioning the relevance of an old paper and different sub-species).
While the species appears to be distributed throughout the western United States (west of the Rocky Mountains) and northern Baja California, Mexico, (Balgooyen 1970; Censke 1986), the subspecies S. g. vandenburgianus is distributed only throughout mountainous areas of southern California and Baja California, Mexico (Stebbins 1985). Zeiner, et al. (1988) states that it is found from 900 to 3200 meters. However, Fisher and Case variously state that the species occurs above 1,500 meters (1997a) or 1,000 meters (1997b) in all counties/mountains in southern California except for Orange (1997a) or Santa Ana Mountains (1997b). In addition the USFWS (1999) directed that analysis would occur from 1,500 meters and above. Therefore, for purposes of this species account it is assumed that they occur at elevations above 1,500 meters in elevation.
Glaser (1970) indicates that the species is present in the Santa Ana Mountains above 3,000 feet and in the San Jacinto and Santa Rosa Mountains at 5,000 feet and above. However, Fisher and Case (1997b) states: "This species is restricted to over 1,000 meters in the mountains of southern California except for the Santa Ana Mountains." This statement could be interpreted to mean that the species is not elevationally restricted within the Santa Ana Mountains, or that it simply does not occur within the Santa Ana Mountains. The USFWS (2002 pers. com.) Has interpreted the statement to mean that the species simply does not occur within the Santa Ana Mountains, end therefore is the assumption within this species account. Historic occurrences have been recorded in the following areas: Fuller's Mill at 5,850 to 7,000 feet; road between Fuller's Mill and Schain's Ranch at 5,500; Hall's Mill site near Schain's Ranch at 5,500 feet; Hall Creekat about 5,000 feet; Idyllwild at 6,000 feet; Strawberry Valley at 6,000 feet; Fern Valley; Keen Camp; Tahquitz Peak at 8,000 feet; canyon east of Round Valley at 8,500 feet; Thomas Mountain; Snow Creek at 5,500 feet; Santa Rosa Peak at 7,500 feet (Glaser 1970). The Santa Ana Mountains location above 3,000 feet is in dispute (USFWS 2002 pers. com.). Based on Glaser (1970) and Zeiner, et al. (1988), suitable habitat is situated around the Cleveland National Forest and San Bernardino National Forest, Anza, and San Jacinto Mountain.
Key population areas occur along the San Jacinto and Santa Rosa Mountains over 1,500 meters.
Genetics: No genetic studies have been completed to differentiate between S. graciosus and other Sceloporus species, nor between the S. graciosus subspecies. The species was first described by Baird and Girard (1852) and later by Van Denburgh (1895). S. g. vandenburgianus was first nominated by Camp (1916). Differentiation between the subspecies is subtle at best and appears to focus around average number of dorsal scales, number of femoral pores, and coloration. However, strictly defined coloration and patterns are typically not good characters for identification of lizards due to variation caused by geography, age, and thermal variation.
Diet and Foraging: S. graciosus is a ground forager (Stebbins 1985) known to prey almost exclusively on small arthropods including ants and beetles (Rose 1976a), other insects, spiders, ticks, mites, scorpions, and others (Knowlton and Janes 1932; Woodbury 1932; Stebbins 1985; Zeiner, et al. 1988) along with occasional scrub oak leaves (Woodbury and Woodbury 1945).
Daily/Seasonal Activity: Like other ectothermic species, S. g. vandenburgianus must regulate its temperature by spending time in and out of direct sunlight, though this species appears to be highly linked to bright, open areas (Stebbins 1985, Woodbury and Woodbury 1945).
The diurnal S. graciosus emerges from hibernation in March or April (Woodbury and Woodbury 1945; Zeiner, et al. 1988) and stays active through September or October with juveniles remaining active longer than adults (Zeiner, et al. 1988). Juveniles emerge first, then males, followed by females (Woodbury and Woodbury 1945). Apparently males emerge from hibernation earlier than females, presumably to establish territories (Noble and Bradley 1933; Woodbury and Woodbury 1945).
Reproduction: S. graciosus usually reproduce from late May through July with egg laying occurring between June and July (Zeiner, et al. 1988; Stebbins 1954) within an approximate 5-week window (Woodbury and Woodbury 1945). Woodbury and Woodbury (1945) determined that Spermatozoa was ready to fertilize from mid-May through early-July and that eggs were discharged and ready for fertilization between May 12 through early July. Between two and eight eggs are laid within a hole dug in loose soil a few centimeters below the surface near the base of a shrub (Stebbins 1985; Zeiner, et al. 1988; Woodbury and Woodbury 1945; Nussbaum, et al. 1983). Larger females may lay more eggs and S. g. vandenburgianus females may lay multiple clutches (Goldberg 1975, Punzo 1982; Stebbins 1985).
Survival: There is no information regarding survivorship.
Dispersal: There is no information regarding dispersal, however Zeiner, et al. (1988) states that they may occasionally move outside the normal zone of activity to find a suitable nest or hibernation site.
Socio-Spatial Behavior: Males are known to have larger home ranges than females (Stebbins 1944) with average maximum movements for males at 24 meters and females 18 meters. Ferguson (1971) found that males actively defend a territory up to 7.5 meters in diameter during the breeding season.
Community Relationships: Competition for food resources with S. occidentalis where the two ranges overlap, was studied by Rose (1976b). Rose, found that there was significant overlap in the prey species taken by each species. However, the microhabitat preferences by the two species (i.e., S. occidentalis prefers vertical substrate while S. graciosus prefers horizontal substrate) probably allow them to live with minimal conflict. Additionally, S. g. vandenburgianus occurs sympatrically with Uta stansburiana at certain locations at high elevations (Fisher and Case 1994).
S. graciosus has been known to be predated by striped whipsnakes and night snakes (Zeiner, et al. 1988), but also are likely to fall prey to a variety of mammals, birds, and reptile species.
Assumed threats to the species include catastrophic fire, off-road vehicle usage, local isolation of populations, road construction, and habitat conversion through climatic or man-made causes. Severe grazing is thought to provide the best habitat structure for them, but may have unfortunate side-effects such as trampling of hibernating individuals or egg clutches.
S. g. vandenburgianus is widely distributed in montane chaparral, hardwood and conifer habitats, juniper habitats, and sage scrub habitats at higher elevations, 1,500 to 3200 meters. The preferred micro-habitat features of S. g. vandenburgianus include open ground, good light and scattered low bushes, and is usually found near bushes, brush heaps, logs, or rocks.
Known prey include ants, beetles, other insects, spiders, ticks, mites, scorpions, and other arachnids.
S. g. vandenburgianus must regulate its temperature by spending time in and out of direct sunlight, and is highly linked to bright, open areas. S. graciosus emerges from hibernation in March or April and stays active through September or October. Males emerge from hibernation earlier than females, to establish territories. Males average maximum movements are 24 meters and females 18 meters. Males actively defend a territory up to 7.5 meters in diameter during the breeding season.
Baird, S.F., and C. Girard. 1852. Descriptions of new species of reptiles collected by the U.S. Exploring Expedition under the command of Captain Charles Wilkes, U.S.N. First Part. Including the species of the western coast of America. Proc. Acad. Natur. Sci. Philadelphia 6:174-177.
Balgooyen, T.G. 1970. The sagebrush lizard - a new locality and comments on its distribution in west central California. California Department of Fish and Game 56:310-311.
Censky, E.J. 1986. Sceloporus graciosus. Catalogue of American Amphibians and Reptiles: 386.1-386.4.
Camp, C.L. 1916. The subspecies of Sceloporus occidentalis with description of a new form from the Sierra Nevada and systematic notes on other California lizards. Univ. Calif. Publ. Zool. 17(7):63-71.
Ferguson, G.W. 1971. Observations on the behavior and interactions of two sympatric Sceloporus in Utah. American Midland Naturalist 86:190-196.
Fisher, R. N., and T. J. Case. 1997a. A field guide to reptiles and amphibians of coastal southern California. Publication sponsored by the Biological Resources Division of the U. S. Geological Service. Website developed by Catherine Vouchilas, California Department of Fish and Game.
Fisher, R.N., and T. J. Case. 1997b. Survey of reptile and amphibian species at risk in southern California forests. Final report to U.S. Forest Service. July 1997. Pp16 + appendix.
Glaser, H. S. R. 1970. The distribution of amphibians and reptiles in Riverside, California. Riverside Museum Press, Riverside, California. Pp. 19.
Goldberg, S.R. 1975. Reproduction in the sagebrush lizard, Sceloporus graciosus. American Midland Naturalist 93:177-187.
Knowlton, G.F., and M.J. Janes. 1932. Studies of the food habits of Utah lizards. Ohio Journal of Science 32:468-469.
Noble, G.K. , and H.T Bradley. 1933. The mating behavior of lizards; its bearing on the theory of sexual selection. Annals N. Y. Acad. Sci., Vol. XXXV, July pp. 25-100.
Nussbaum, R.A., E.D. Brodie, and R.M. Storm. 1983. Amphibians and reptiles of the Pacific northwest. Univ. Press Idaho, Moscow. 332 pp.
Punzo, F. 1982. Clutch and egg size in several species of lizards from the desert southwest. Journal of Herpetology 16:414-417.
Rose, B.R. 1976a. Dietary overlap of Sceloporus occidentalis and S. graciosus. Copeia 1976:818-820.
________. 1976b. Habitat and prey selection of Sceloporus occidentalis and S. graciosus. Ecology 57:531-541.
Stebbins, R. C. 1985. A field guide to western reptiles and amphibians. Houghton Mifflin, Boston. Pp. 123-124.
Van Denburgh, J. 1895. A review of the herpetology of lower California. Part I. Reptiles. Proc. Calif. Acad. Sci. Ser. 2, 5:77-162.
Zeiner, D. C., W. F. Laudenslayer, Jr., and K. E. Mayer (compiling editors). 1988. California''s wildlife. Volume I. Amphibians and reptiles. California Statewide Wildlife Habitat Relationships System, California Department of Fish and Game, Sacramento, California.
western pond turtle (Clemmys marmorata pallida)
State: Species of Special Concern
Federal: None
The western pond turtle has narrow habitat requirements and potentially limited distribution within the Plan Area, typically being restricted to slow moving permanent or intermittent streams, small ponds, small lakes, reservoirs, and other long term water deposits, where abundant cover is available. The pond turtle may also use adjacent uplands up to 2 km from water bodies. Currently, the species is known from throughout the Plan Area, but key areas appear to be at the confluence of Temecula Creek and Murrieta Creek, Santa Ana River, Santa Rosa Plateau, and San Jacinto River. Because the pond turtle requires very specific habitat conditions and uses a well defined habitat that is narrowly distributed, this species will require site specific considerations, protection of primary habitat and adjacent upland areas, and species-specific conservation measures.
The species-specific conservation objectives developed for this species are based upon the best available scientific information at the time of MSHCP preparation. Pursuant to Section 5.0 which includes Management, Monitoring and the Adaptive Management Program, the MSHCP's mitigation requirements will be monitored and analyzed to determine if they are producing the desired result. Based upon this information, the following species-specific conservation objectives will be adjusted if appropriate, as new information is gathered during Plan implementation. The Adaptive Management Program will be used to identify alternative strategies for meeting the MSHCP's general biological goals and objectives and, if necessary, adjusting future conservation strategies according to the information received.
Include within the MSHCP Conservation Area at least 18,289 acres of suitable primary pond turtle habitat (open water, meadows and marshes, and riparian scrub, woodland and forest). Conservation areas will include slow moving permanent or intermittent rivers and streams, small ponds, wetlands, arroyos, vernal pools, small lakes, abandoned gravel pits, permanent stock ponds, sewage treatment lagoons, reservoirs, areas with submerged rocks and roots, emergent basking sites, partially submerged logs, emergent (matted) vegetation, rocks and mudbanks.
Include within the MSHCP Conservation Area at least eight Core Areas, including but not limited to, Cajalco Creek (7,849 acres), San Mateo Creek (18,375 acres), Santa Ana River (34,598 acres), Chino Creek (2,446 acres), Temecula Creek (17,784 acres), Murrieta Creek (23,084 acres), Santa Rosa Plateau (17,187 acres), and San Jacinto River (70,294 acres). Please note that the acreages include all habitats within the 2 kilometer buffer area and river/creek system.
Include within the MSHCP Conservation Area 59,999 acres of upland habitat including grasslands, oak woodlands, chaparral, seasonal flood plains, coastal sage scrub, and other habitats within about 2 km of water bodies within the MSHCP Conservation Area lands adjacent to the riparian woodland.
Include within the MSHCP Conservation Area riparian/wetland and overland dispersal habitat along the Santa Margarita River, Temecula Creek, Murrieta Creek, San Jacinto River, Temescal Wash, Santa Ana River, San Timoteo Canyan Creek, Sycamore Canyon Creek, Kolb Creek, Wilson Creek, Cottonwood Creek, Tule Creek, San Gorgonio Wash, Bautista Creek, Poppet Creek, portions of Diamond Valley Lake, Vail Lake, Lake Elsinore, Lake Mathews, Lake Perris, portions of Canyon Lake, and numerous creeks, pools, and other water bodies on Forest Service lands.
Within the MSHCP Conservation Area, maintain continued use at a minimum of 75 percent of the conserved Core Areas as measured once every 3 years.
For purposes of this conservation analysis, suitable primary habitat for this species includes bodies of water, marshes, riparian scrub, woodland, and forest, and associated uplands up to an elevation of 2,000 m. Adjacent uplands will be preserved to the maximum extent possible, based on the their current condition and availability for conservation. Suitable secondary upland habitats include, grasslands, oak woodlands, chaparral, coastal sage scrub, and Riversidean alluvial sage scrub within 2 kilometers of suitable wetland habitat. For purposes of this analysis, only upland habitats adjacent to the core wetland habitats as discussed below. Additional upland habitats will be available adjacent to other conserved wetland habitat within the MSHCP Conservation Area. Acreages for wetland habitats are provided in Table 1 and acreages for adjacent upland habitat are provided in Table 2. Due to the paucity of data points, species conservation cannot be based on preservation of known locations of species occurrence alone. Instead, conservation must also be based on habitat preservation within the key areas, as directed by historical information and on known habitat requirements. Various monitoring and maintenance activities, will also be very important for this species.
Based on these habitats, the Plan Area supports approximately 23,701 acres of potential wetland habitat for the western pond turtle. Similarly, the Plan Area supports approximately 94,067 acres of suitable upland habitat which is within 2 km of the eight Core Areas which are described below. Approximately 18,289 acres (77 percent) of the potential wetland habitat and 59,999 acres (64 percent) of the potential upland habitat in the Plan Area would be conserved in the MSHCP Conservation Area. It is assumed that these lands would be managed for wildlife resources including the western pond turtle.
TABLE 1
SUMMARY OF PRIMARY WETLAND HABITAT CONSERVATION
WESTERN POND TURTLE
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Meadow and Marshes | 470 | 174 | 211 | 385 | 0 | 57 | 57 |
| Riparian Scrub, Woodland and Forest | 14,606 | 3,920 | 7,220 | 11,140 | 368 | 3,045 | 3,413 |
| Open Water | 8,625 | 1,188 | 5,576 | 6,764 | 36 | 1,825 | 1,861 |
| TOTAL | 23,701 | 5,282 | 13,007 | 18,289 | 404 | 4,927 | 5,331 |
| 1 Total acres is not broken down by geographic area, and only includes habitats up to 2,000 m in elevation. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
TABLE 2
SUMMARY OF UPLAND HABITAT CONSERVATION
WESTERN POND TURTLE
| Vegetation Type | MSHCP Plan Area1 (Acres) |
Within MSHCP conservation Area | Outside MSHCP conservation Area | ||||
|---|---|---|---|---|---|---|---|
| Criteria Area2 (Acres) |
Public/ Quasi-Public (Acres) |
Total Within MSHCP Conservation Area (Acres) |
Rural/ Mountainous (Acres) |
Outside MSHCP Conservation Area (Acres) |
Total Outside MSHCP Conservation Area (Acres) |
||
| Chaparral | 45,463 | 5,292 | 29,440 | 34,732 | 6,730 | 4,001 | 10,731 |
| Coastal Sage Scrub | 15,809 | 6,432 | 4,121 | 10,553 | 1,510 | 3,746 | 5,256 |
| Grassland | 24,960 | 2,578 | 6,138 | 8,716 | 1,764 | 14,480 | 16,244 |
| Riversidean Alluvial Fan Sage Scrub | 2,566 | 1,082 | 1,043 | 2,125 | 6 | 435 | 441 |
| Woodlands and Forest | 5,269 | 605 | 3,268 | 3,873 | 966 | 430 | 1,396 |
| TOTAL | 94,067 | 15,989 | 44,010 | 59,999 | 10,976 | 23,092 | 34,068 |
| 1 Total acres is not broken down by geographic area, and only includes habitats up to 2,000 m in elevation and within 2 km of primary habitat Core Areas. 2 Acres refer to Additional Reserve Lands to be assembled from within the Criteria Area. |
|||||||
Nothing is known about genetic relationships between western pond turtle within its range or within the Plan Area to determine if important genetically distinct and isolated populations occur. However it is generally thought that in the absence of data, it is best to preserve representative populations at the limits of its distribution and range, including latitude, longitude, and elevation. Accordingly, conservation of the western pond turtle will be primarily based on the preservation of at least eight key habitat blocks centered around the following wetland areas and include a two-kilometer buffer: Cajalco Creek (7,849 acres), San Mateo Creek (18,375 acres), Santa Ana River (Existing Core A; 34,598 acres), Chino Creek (2,446 acres), Temecula Crek (Proposed Constrained Linkages 14 and 24, plus Existing channel; 17,784 acres), Murrieta Creek (Proposed Constrained Linkage 13; 23,084 acres), Santa Rosa Plateau (Existing Core F; 17,187 acres), and San Jacinto River (Proposed Core 5, plus Existing Constrained Linkage C, plus Proposed Extension of Existing Core 4; 70,294 acres). Also, a few large blocks which include both appropriate wetland and upland habitats, including Lake Mathews/Lee Lake (Existing Core C plus Proposed Extension of Existing Core 2 and Proposed Core 1; 31,180 acres), Vail Lake/Aguanga (Proposed Core 7; 50,000 acres), Lake Skinner/Diamond Valley (Existing Core J plus Proposed Extension of Existing Cores 5, 6, and 7; 29,070 acres), San Jacinto Wildlife Area/Lake Perris (Existing Core H; 17,470 acres), Anza Valley (Proposed Core 6; 4,290 Acres), Agua Tibia Wilderness (Existing Core M; 10,460 acres), and Santa Ana Mountains foothills (Existing Core B; 71,490 acres), will be included within the MSHCP Conservation Area. The large blocks typically include creek and tributary buffers of one kilometer or more, while the smaller areas are already generally constrained by existing development. Some of the small areas have buffers with widths of over one kilometer, while others have much smaller buffers. Protection of resources on U.S. Forest Service lands and protection of wetland resources will be provided. Other Public/Quasi-Public areas are currently managed by respective agencies and new reserve areas will be managed for the benefit of wildlife including the western pond turtle.
Movement across large roads and freeways will be hindered in areas without large vehicular overpasses. It is possible that the western pond turtle may utilize long and narrow under crossings to occupy new habitat, though wider under crossings will be more useable. Over-road movement of pond turtles will probably result in mortality.
Implementation of the MSHCP, including the conservation of existing populations and suitable habitat as described above, will maintain viable populations of the western pond turtle. The current population size and distribution is unknown, but is relatively easily censussed. The MSHCP will conserve large Core Areas and interconnecting habitat linkages that are suitable for occupation by the western pond turtle in the large habitat blocks discussed above. Populations should remain viable in the habitat blocks. Smaller occupied areas, as listed above, may be at higher risk of extirpation either rapidly as a result of some catastrophic event, or over the longer term as a result of demographic or genetic stochasticity (e.g., random birth and death rates, inbreeding depression, genetic drift) or through indirect impacts (e.g., road mortality, poaching) from surrounding urbanization.
In summary, conservation for the western pond turtle will be achieved by the inclusion of at least 78,288 acres of suitable Conserved wetland and upland Habitat within at least eight Core Areas which are composed of suitable occupied wetland areas and surrounding upland buffers and other large blocks of habitat within the MSHCP Conservation Area. The Core Areas are provided with numerous connections of Proposed and Existing Cores. In addition, the MSHCP Plan will maintain continued use at a minimum of 75 percent of the conserved Core Areas as measured once every three years. The current population size of the western pond turtle is unknown, but the general distribution is, and the species is generally readily detectable. Furthermore, the Plan Area is contiguous with suitable habitat in eastern Riverside, San Bernardino, Orange, and San Diego counties.
The Incidental Take of the western pond turtle is difficult to quantify due to our limited knowledge of its distribution and abundance within the Plan Area. The maximum level of Incidental Take of western pond turtle can be anticipated by the loss of the number of acres of potential habitat that will become unsuitable for this species. Approximately 5,331 acres (22 percent) of suitable wetland habitat and 34,068 acres (36 percent) of suitable adjacent upland habitat will be outside the MSHCP Conservation Area and individuals within these areas will be subject to Incidental Take consistent with the Plan.
The MSHCP data base includes 36 records for the western pond turtle between 1999 and 1940. Of the 36 records, 11 (31 percent) are precision code "1" (an "x" and "y" coordinate that allows for good precision in the location), 4 (11 percent) are precision code "2" (one "x" or "y" or equivalent); and the remaining 21(58 percent) are precision codes "3" or "4" (relatively imprecise locations from general areas). Most of the precision code "1" or "2" records are recent, with 12 (80 percent) since 1990 and 3 (20 percent) pre-dating 1990 or with no associated date. The reason for the lack of records is likely due to a lack of survey effort due to perceived lack of sensitivity, confusion with non-native turtles, and lack of reporting. Abundant information is available in the literature on the western pond turtle; however, it is apparent that more information is needed regarding dispersal and community relationships.
The records are located in three general areas of the Plan Area. These include the Santa Margarita/Murrieta Creek/Temecula Creek confluence and watershed, the San Jacinto Mountain watershed, and the Santa Ana River. In addition, turtles have ben located at Lake Mathews and likely occur at the other large reservoirs and lakes (e.g., Lake Skinner, Lake Perris, Lake Elsinore, Vail Lake).
The western pond turtle inhabits slow moving permanent or intermittent streams, small ponds, small lakes, reservoirs, abandoned gravel pits, permanent and ephemeral shallow wetlands, stock ponds, and sewage treatment lagoons (Rathbun et al., 1992; Holland, 1994). Pools are the preferred habitat within streams (Bury, 1972). Abundant logs, rocks, submerged vegetation, mud, undercut banks, and ledges are necessary habitat components for cover as well as a water depth greater than 2 meters (Brattstrom and Messer, 1988; Holland, 1994). Additionally, emergent basking sites, emergent vegetation and the availability of suitable terrestrial shelter and nesting sites seem to characterize optimal habitat. Adjacent upland areas typically provide overwintering and estivation sites.
The historical range of the western pond turtle extended along most of the west coast of North America, primarily west of the Cascade-Sierra crest, from western British Colombia to northern Baja California (Ernst et al., 1994). Currently, it ranges south of San Francisco Bay to northern Baja California, Mexico, and integrades with northwestern pond turtle (C.m. marmorata) over a large area in central California (Bury, 1970, Stebbins, 1985). The presence of pond turtles in the Mojave Desert has been established by fossils in the Camp Cady area, dating at least to the Pleistocene (Jefferson, 1968). Isolated populations are known to exist as far into the Mojave Desert as Afton Canyon, and in the Amargosa River, County of Los Angeles (Lovitch, 1999). Truckee, Humboldt, and Carson Rivers in Nevada, Puget Sound, and the Columbia Gorge historically supported disjunct populations (Lovitch, 1999). The elevational range for the species is from brackish estuarine waters at sea level to over 2,000 meters, but it's uncommon over 1,529 meters (Stebbins, 1954; Bury, 1963; Holland, 1994).
Within Riverside County, the western pond turtle generally ranges from the Santa Ana River, to Chino Creek, along the eastern slopes of the Santa Ana Mountains and Elsinore Mountains, south to the Temecula River at I-15 (Brattstrom and Messer, 1988). Temecula Creek, at the confluence of Murrieta Creek, appears to be a key area. Additional important localities include the Santa Rosa Plateau, San Jacinto River, and Santa Ana River.
Currently known and historical locations associated with wetland areas are found in the general vicinity of Canyon Lake, El Cerrito, Long Canyon, Murrieta, Pedley, Perris, Riverside, Riverside east, Sage, San Mateo Canyon, Temecula, Wildomar, Arroyo Seco Creek, Cajalco Creek, Murrieta Creek, San Jacinto River, Santa Ana River, Santa Margarita River, Temecula Creek, Temescal Wash, Tucalota Creek, Wilson Creek, Elsinore Mountains, Santa Ana Mountains, Cleveland National Forest, Lake Skinner Reserve, Santa Rosa Plateau, and Santa Ana River Regional Park.
Genetics: The northwestern pond turtle (Clemmys marmorata marmorata) and southwestern pond turtle (Clemmys marmorata pallida) are the two subspecies recognized. The northwestern subspecies is distinguished by a pair of well-developed triangular inguinal scutes on the bridge, where the southwestern subspecies has poorly developed inguinal scutes (absent in 60 percent of individuals). In addition, the northwestern form has a pale throat in contrast with its head, while the southwestern form has a more uniform light color of the throat and neck (Stebbins, 1985; Lovitch, 1999).
DNA fingerprinting supports the distinctiveness of the two subspecies (Gray, 1995; Janzen et al., 1997). Holland (1992) suggests that the Colombia river population is comprised of a third subspecies; and the Mojave River population shows distinct morphological differentiation from other populations in southern California. Janzen et al. (1997) suggested that southern populations may be distinct enough to be recognized as a separate species, although all populations continue to be recognized as C. marmorata, as no formal taxonomic revisions have been published.
Diet and Foraging: C. marmorata is an omnivorous feeder with a broad feeding niche, but does not select food items on general availability (Bury, 1986). It scavenges, but also takes live prey, acting as an opportunistic predator. Adults ingest plants as part of their diet, which provides nutrients when live prey are unobtainable, but tend to prefer live or dead animal food instead of plant material. Many small animals such as fish, crustaceans, worms and insects abound in the filamentous algae eaten by the pond turtle. Among the many types of food items eaten by the pond turtle are aquatic plants such as the pond lily (Nuphar polysepalum), water beetles, mallard duck carrion, adult larval insects, coyote scat, and snails (Pope, 1939; Evenden, 1948; Carr, 1952; Holland, 1988; Bury, 1986; Goodman and Stewart, 1998).
Bury (1986) found that prey sizes and proportions of prey items differ between age and sex classes. This may reduce intraspecific competition for limited resources. His data reveal that females utilize a higher variability (20 categories) in food items than males (15 categories) and juveniles were found to utilize the most (22 categories).
The pond turtle has no specialized morphological features to aid in feeding and shows little sexual dimorphism (Seeliger, 1945; Bury, 1970, 1986).
Daily Activity: The western pond turtle's daily activity revolves around thermoregulation and foraging patterns. It often suns itself at the edge of water, or on branches or stones above water. It is secretive and will seek refuge at the bottom of a pond or stream at the slightest disturbance. In the early morning and evening, pond turtles may move up or downstream, moving from one pool to the next in search of basking sites, mates or foraging. Northern populations tend to forage early in the morning, then usually begin basking between 0900-1000, and continue basking intermittently throughout the day. They usually terminate basking at around 90-95 degrees Fahrenheit (F.), maintaining a body temperature of 75-90 degrees F. for most activities (Bury 1972). Foraging may occur during the late afternoon or early evening during the warmth of summer. Often they will remain quietly on the bottom of pools to avoid a critical thermal maximum of 104 degrees F.
Geographical variation occurs in the seasonal activity of the pond turtle, although in warmer portions of its range, it may be active in every month (Holland, 1994). The primary activity period is February-November for the northern portion of its range (Evenden, 1948; Bury, 1972).
Reproduction: Courtship and mating behaviors of the western pond turtle have been observed from February through November (Holland, 1988; Buskirk, 1991; Goodman, 1997a). Goodman (1997) found that females begin laying eggs at a carapace length greater than 11cm, and Holland (1994) suggests an age of approximately 6-7 years. Depending on latitude, the peak nesting season is from late May through early July, but extends from late April through August (Holland, 1994).
If suitable nesting sites are not available, females have been observed to travel up to 1.2 miles along a waterway to lay their eggs (Rathbun et al., 1992). Nests are typically located along stream or pond margins, however, they may be located over 100m from water on hillsides. Terrestrial nest locations (6) inspected by Rathbun et al. (1992) were all found in open, grassy areas with a southern exposure. Holland (1994) reports that nesting forays onto land may require several days, however, Rathbun et al. (1992) reported an overnight trip. The female left the water in the evening (between 1700-2000) and returned in the morning (between 0815-0900). Nest cavities were pear-shaped and measured 2.6-3.1 inches (6.5-8.0 cm) deep with a 2.6-2.8 inch (6.5-7.0 cm) wide egg chamber and a 1.4-1.6 inch (3.5-4.0 cm) mouth (Rathbun et al. 1992). Usually nest excavation occurs in the morning or evening (Storer 1930).
Average clutch size (6.12; range 1-13) and possibly mean egg width is significantly correlated with body size (Holland, 1994; Goodman, 1997). Double clutching has been observed in pond turtles of San Bernardino County (Goodman 1997). In three of seven females observed by Goodman (1997), first clutches were laid between May 4-14, and second clutches between June 10-20. Double clutch sizes didn't differ significantly within individual females, nor did mean egg width. Many females do not lay eggs every year. In three consecutive years, Goodman (1997) found that 3 of 8, 7 of 14, and 3 of 9 were gravid. Additionally, of the 15 females (of potential reproductive size) studied, only two clutched in two consecutive years, and only one clutched in three consecutive years.
Incubation period varies with latitude, but is typically 80-126 days (Goodman, 1997a; Holland, 1994). Lardie (1975) and Feldman (1982) incubated eggs at 77-91o F and determined an incubation period of 73-81 days. Hatchlings did not leave the egg if the temperature exceeded 81o F, but they emerged within 2-3 hours after moving the egg to a cooler environment (Feldman 1982). Environmental sex determination occurs in pond turtles. At low incubation temperatures, males are produced and females at high temperatures. Ewert et al. (1994) found the pivotal temperature to be approximately 86o F.
Complete failure of nests is not uncommon in some years or locations (Holland 1994). Goodman (1997) observed an 80 percent hatchling success rate for 15 eggs in three nests, however, Holland (1994) reports an overall average of 70 percent. In the northern portions of their range, hatchlings remain in the nest through the winter, although in southern California, most emerge in the early fall (Holland 1994).
Survival: Lovitch (1999) reports annual survivorship of 10-15 percent for 1-3 year age classes. Average annual adult mortality is 3-5 percent (Holland 1994).
Dispersal: No dispersal information exists.
Socio-Spatial Behavior: Bury (1972) found that distribution of turtles is not uniform, with aggregations occurring in pools. This results in spatial competition for limited resources, such as basking sites, at any given pool. Aggressive behaviors are exhibited by western pond turtles competing for adequate spacing at basking sites (Bury and Wolfheim, 1973). Biting, ramming and pushing behaviors were observed between pond turtles to secure preferred basking sites. An aggregation of 19 western pond turtles located in a crevice of granitic rock near a stream was reported by Holland and Goodman (1996).
In a radiotelemetry study by Rathbun et al. (1992), daily movements of four females during one month from May 20 to June 21, 1989, averaged 28 meters (m), 55 m, 61 m, and 87 m, respectively. Home range sizes vary between age and sex classes. Bury (1972) studied a population in a northern California stream and found that adult males had the largest range, averaging 2.42 acres with a mean length of 976 m. Adult female home ranges averaged 0.62 acre with a mean length of 248 m. Juveniles had the smallest home ranges, averaging 0.89 acre and 363 m. Data for in-stream movement displayed similar trends. A larger percentage of males and juveniles, 54 percent and 33 percent respectively, moved upstream rather than downstream (34 percent and 27 percent respectively). The observed number of females moving up and down stream was nearly the same at 39 percent (downstream) and 33 percent (upstream). While moving between pools within the stream system, average distances were 354 m for males, 169 m for females, and 142 meters for juveniles. Greater than 81 percent of males moved over 200 m, while only 37 percent of females and 23 percent of juveniles traveled that distance. When looking at percentages of the population that moved greater than 500 m, Bury (1972) found that only 6 percent of juveniles and females, and 27 percent of males traveled that distance. In three years, males averaged 817 meters but they are capable of distances of at least 1 mile (Bury 1972), and up to 3.1 miles over land (Holland 1994) to adjacent water bodies.
Community Relationships: No information regarding community relationships exists.
Loss and alteration of aquatic habitat is the greatest threat to the western pond turtle. Over 90 percent of wetland habitat within its historic California range has been eliminated by agricultural development, flood control, water diversion projects, and urbanization (U.S. Fish and Wildlife, 1992, 1993). Additionally, predation on young by introduced aquatic species (e.g., bullfrogs, bass, and catfish) collection for pets, urban-related predation pressures (e.g., dogs raccoons, skunks), competition with non-native turtles (Holland, 1991), contaminant spills, grazing, off-road vehicle use and vehicle strikes on roads (Holland, 1994) have all contributed to sharp decline this species has experienced in recent decades. Dams and channelization have greatly reduced the availability of suitable habitat (Brattstrom and Messer, 1988). Reese and Welsh (1988) determined that the quality of western pond turtle habitat has been reduced by alteration of channel morphology and flow rates associated with dam construction. Invasion of exotic vegetation species such as tamarisk (Tamarix sp.) is another threat to the pond turtle. Establishment of tamarisk results in changes to hydrology and channel morphology which degrades pond turtle habitat.
Habitat fragmentation is associated with these threats and results in a reduction of genetic variability. The survival of the Oregon, Washington, and Mojave River populations may be significantly threatened by loss of genetic variability. These populations display a high degree of genetic similarity which reflects a lack of dispersal and gene flow and is probably a consequence of habitat fragmentation (Lovitch, 1999). Gray (1995) reports a much higher genetic variability in southern California populations.
Destruction of suitable habitat appears to be the biggest threat to populations of the western pond turtle (Brattstrom, 1988; Brattstrom and Messer, 1988). Today, the only extensive populations remaining are in northern California and southern Oregon. In recent years, the southern California pond turtle population has experienced an alarming decline. Between Ventura County and the Mexican border, known localities have decreased from 87 in 1960, to 57 in 1970, and as of 1987, only 10 of 255 sites inspected were thought to support reproductively viable populations (Brattstrom, 1988; Brattstrom and Messer, 1988; Lovitch, 1999). Fifty-three of the 255 sites inspected contained pond turtles, the distribution of these sites follows: 25 in Ventura County, 10 in Los Angeles County, eight in San Diego County, four in Orange County, three in southwestern San Bernardino County, and three in western Riverside County.
Conservation management of aquatic turtles should include not only protection of aquatic habitat, but also preservation and restoration of dispersal corridors and adjacent terrestrial habitat (potentially 500 m or more from the wetland boundary) for nesting, hibernation, and estivation (Holland, 1994; Burke and Gibbons, 1995). These corridors should also be protected from impacts associated with exotic plant and animal species, new road construction, cattle and off-road vehicle use. Reintroductions and the establishment of satellite populations would also contribute to the protection of the pond turtle. In Riverside County, the Desert Studies Center at Zzyzx and Dos Palmas Oasis would be suitable such activities (Lovitch, 1999).
Brattstrom, B.H. 1988. Habitat destruction on California with special reference to Clemmys marmorata: a perspective. pp. 13-24. In: H. F. DeLisle, P. R. Brown, B. Kaufman and B. M. McGurty (eds.). Proceedings of the Conference on California Herpetology. Southwestern Herpetological Society, Van Nuys, California.
Brattstrom, B.H. and D.F. Messer. 1988. Current status of the southwestern pond turtle, Clemmys marmorata pallida, in southern California. Final Report for California Department of Fish and Game, Contract C-2044. 47 pp. + xii.
Burke, V.J. and J.W. Gibbons. 1995. Terrestrial buffer zones and wetland conservation: a case study of freshwater turtles in a Carolina bay. Conserv. Biol. 9: 1365-1369.
Bury, R.B. 1970. Clemmys marmorata. Catalogue of American Amphibians and Reptiles 100:1-3.
Bury, R.B. 1963. Occurrence of Clemmys m. marmorata in north coastal California. Herpetologica. 18:283.
Bury, R.B. 1972. Habits and home range of the Pacific pond turtle, Clemmys marmorata, in a stream community. Ph.D. Diss. Univ. California, Berkeley.
Bury, R.B. 1986. Feeding ecology of the turtle, Clemmys marmorata. J. Herpetol. 20:515-521.
Bury, R.B. 1989. Turtle of the month- Clemmys marmorata - a true western turtle (Pacific pond). Tortuga Gazette. 25(2):3-4.
Bury, R.B. and D.J. Germano. 1998. Annual deposition of scute rings in the western pond turtle, Clemmys marmorata. Chelonian Conserv. Biol. 3:108-109.
Bury, R.B., and J.H. Wolfheim. 1973. Aggression in free-living pond turtles (Clemmys marmorata). Bioscience. 23:659-662.
Buskirk, J.R. 1991. An overview of the western pond turtle, Clemmys marmorata. pp. 16-23. In, K.R. Beaman, F. Caporaso, S. McKeown and M.D. Graff (eds.). Proceedings of the First International Symposium on turtles and tortoises: conservation and California.
Carr, A. F. 1952. Handbook of turtles. The turtles of the United States, Canada, and Baja, California. Ithaca, New York: Comstock Publ. Assoc., Cornell Univ. Press. Ithaca, New York.
Dudley, T. and B. Collins. 1995. Biological invasions in California wetlands. Pacific Institute for Studies in Development, Environment, and Security. Oakland, California.
Ernst, C.H., J.E. Lovich, and R.W. Barbour. 1994. Turtles of the United States and Canada. Smithsonian Institution Press, Washington, D.C.
Evenden, G.G., Jr. 1948. Distribution of the turtles of western Oregon. Herpetologica 4:201-204.
Ewert, M.A., D.R. Jackson and C. Nelson. 1994. Patterns of temperature-dependent sex determination in turtles. J. Exp. Zool. 270:3-15.
Feldman, M. 1982. Notes on reproduction in Clemmys marmorata. Herpetol. Rev. 13:10-11.
Goodman, R.H., Jr. 1997a. The biology of the southwestern pond turtle (Clemmys marmorata pallida) in the Chino Hills State Park and the West Fork of the San Gabriel River. Master's Thesis, California State Polytechnic University, Pomona.
Goodman, R.H., Jr. 1997b. Occurrence of double clutching in the southwestern pond turtle, Clemmys marmorata pallida in the Los Angeles Basin. Chelonian Conserv. Biol. 2:419-420.
Goodman, R.H. and G.R. Stewart. 1998. Clemmys marmorata pallida (southwestern pond turtle). Coprophagy. Herpetol. Rev. 29(2):98.
Gray, E.M. 1995. DNA fingerprinting reveals a lack of genetic variation in northern populations of the western pond turtle (Clemmys marmorata). Conserv. Biol. 9(5):1244-1255.
Holland, D. C. 1988. Clemmys marmorata (Western Pond Turtle). Behavior. Herpetol. Rev. 19:87-88.
Holland, D.C. 1991. A synopsis of the ecology and status of the western pond turtle (Clemmys marmorata) in 1991. Unpublished report prepared for the U.S. Fish and Wildlife Service. 141 pp.
Holland, D.C. 1992. Level and pattern in morphological variation: a phylogeographic study of the western pond turtle (Clemmys marmorata). Ph.D. Diss., University of Southwestern Louisiana.
Holland, D.C. 1994. The western pond turtle: habitat and history. U.S. Department of Energy, Bonneville Power Administration, Portland, Oregon. 11 chapters + appendices.
Holland, D.C. and R.H., Jr. Goodman. 1996. Clemmys marmorata (western pond turtle). Terrestrial habitat use. Herpetol. Rev. 27(4):198-199.
Janzen, F.J., S.L. Hoover, and H.B. Shaffer. 1997. Molecular phylogeny of the western pond turtle (Clemmys marmorata): preliminary results. Linnaeus Fund Research Report. Chelonian Conserv. Biol. 2:623-626.
Jefferson, G.T. 1968. The Camp Cady local fauna from Pleistocene Lake Manix, Mojave Desert, California. Master's Thesis, University of California, Riverside.
Jennings, M.R. and M.P. Hayes. 1994. Amphibian and reptile species of special concern in California. California Department of Fish and Game, Rancho Cordova, California. 255 p.
Lardie, R.L. 1975. Notes on eggs and young of Clemmys marmorata marmorata (Baird and Girard). Occ. Pap. Mus. Natur. Hist. Univ. Puget Sound. 47:654.
Lovich, J.E. and R.G. de Gouvenain. 1998. Saltcedar invasion in desert wetlands of the southwestern United States: ecological and political implications. pp. 447-467. In: S. K. Majumdar, E. W. Miller, and F. J. Brenner (eds.). Ecology of Wetlands and Associated Systems. Pennsylvania Acad. Sci.
Lovich, J.E., T.B. Egan, and R.C. de Gouvenain. 1994. Tamarisk control on public lands in the desert of southern California: two case studies. 46th Annual California Weed Conference, California Weed Science Society. pp. 166-177.
Lovitch, J.E. 1999. Western Pond Turtle Clemmys marmorata. Department of Biology, University of California, Riverside.
Overtree, L. and G. Collings. 1997. Western pond turtles in the Kern Valley region. The Tortuga Gazette (California Turtle and Tortoise Club). 33: 1-2.
Pope, C.H. 1939. Turtles of the United States and Canada. Alfred A. Knopf., Inc. New York, New York.
Rathbun, G.B., N. Siepel and D. Holland. 1992. Nesting behavior and movements of western pond turtles, Clemmys marmorata. Southwest. Nat. 37:319-324.
Reese, D.A. and H.H. Welsh, Jr. 1988. Habitat use by western pond turtles in the Trinity River, California. J. Wildlife Manag. 62:842-853.
Schneider, J.S., and G.D. Everson. 1989. The desert tortoise (Xerobates agassizii) in the prehistory of the southwestern Great Basin and adjacent areas. J. California Great Basin Anthropol. 11:175-202.
Seeliger, L.M. 1945. Variation in the Pacific mud turtle. Copeia. 1945:150-159.
Slater, J.R. 1962. Variations and new range of Clemmys marmorata marmorata. Occ. Pap. Mus. Nat. Hist. Univ. Puget Sound. 20:204-205.
Stebbins, R.C. 1954. Amphibians and reptiles of western North America. New York: McGraw Hill Book Co., New York, New York.
Stebbins, R.C. 1985. A field guide to western reptiles and amphibians, 2nd ed. Houghton Mifflin Co., Boston, Massachusetts.
Storer, T.I. 1930. Notes on the range and life history of the Pacific fresh water turtle, Clemmys marmorata. Univ. California Publ. Zool. 32:429-441.
U.S. Fish and Wildlife Service. 1992. Endangered and threatened wildlife and plants; 90-day finding and commencement of status reviews for a petition to list the western pond turtle and California red-legged frog. Fed. Reg. 57:45761-45762.
U.S. Fish and Wildlife Service. 1993. Endangered and threatened wildlife and plants; notice of a 1-year petition finding on the western pond turtle. Fed. Reg. 58:42717-42718.