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. |
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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.
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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.
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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