occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) The range is primarily west of the Cascade-Sierra Nevada crest from south-central Washington and north-central Oregon (mainly west of Cascade crest) south through western Oregon and California to northern Baja California, including islands off southern California and northern Baja California (Stebbins 2003). Isolated populations exist east of the Sierra Nevada at Grant Lake, Mono County, California; Alabama Hills and Walker Pass, Kern County, California; Walker Creek near Olancha, Inyo County, California, and along the Mojave River, California; there is also an isolated occurrence at Sierra La Asamblea, Baja California Sur (Stebbins 2003). The species was introduced at Las Vegas, Nevada (Stebbins 2003). Unconfirmed sight record at Boulder Beach Campground, Clark County, Nevada (Stebbins 2003). DNA data suggest that the population on San Nicolas Island, California, may have been recently transported there (Mahoney et al. 2003). Elevational range is from sea level to around 5,000 feet (1,524 meters) (Stebbins 2003).
Distribution: USA (Washington, Oregon, California), Mexico (Baja California) ignava: San Martin Island, Baja California nana: Los Coronados Island, Baja California.
Type locality: South island, Los Coronados Island, Baja California. webbii: S California, N Baja California.
Type locality: “San Diego to El Paso”. Restrcited to San Diego, California, by SMITH & TAYLOR 1950.
Length: 43 cm
Catalog Number: USNM 9057
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Locality: No Further Locality Data, Oregon, United States, North America
- Holotype: Baird, S. F. & Girard, C. 1852. Proc. Acad. Nat. Sci. Philadelphia. 6: 176.
Sierra de la Laguna Pine-oak Forests Habitat
This taxon is found in the Sierra de la Laguna pine-oak forest, a mountainous ecoregion which rises from the arid Baja California Sur, creating islands of unique vegetative communities. There are approximately 694 plant species, approximately 85 of which are endemic to this ecoregion. Overall species richness is low to moderate, with a total of only 231 vertebrate taxa. The ecoregion is classified in the Tropical and Subtropical Coniferous Forests biome. Much of the pine-oak association remains intact due to the inaccessibility of the rugged and inaccessible terrain.
The topographical features and geological events that gave rise to this particular region are responsible for the diversity of climates and vegetation in the same area. The highest strata of mountains, situated at 1600 to 2000 metres (m) in elevation, are composed of pine-oak forests that transform into oak-pine forests (1200 m) and oak forests (800 m) as elevation decreases. The climate is temperate sub-humid with summer rains and occasional winter rains.
These pine-oak forests constitute the wettest portions in the state of Baja California Sur (760 millimetres of precipitation annually). Slight variations in climatic conditions make up three different vegetation assemblages in the temperate forest. Pine forests at the highest elevations are dominated by Pinus cembroides ssp. lagunae, and understory taxa such as Muhlenbergia spp. and Festuca spp. Pine-oak forests dominated by associations of Pinus cembroides subsp. lagunae with Quercus devia, Arbutus peninsularis, and Quercus tuberculata, and a variety of trees of smaller stature such as Calliandra peninsularis and Mimosa tricephala, with associated shrubs to complement the landscape.
Some of the endemic reptiles are the Southern Alligator Lizard (Elgaria multicarinata) and the Yucca Night Lizard (Xantusia vigilis). Other reptilian taxa found in the Sierra de la Laguna pine-oak forests include the Baja California Rock Lizard (Petrosaurus thalassinus), Baja California Rattlesnake (Crotalus enyo) and the Baja California Brush Lizard (Urosaurus nigricaudus).
Only two amphibian taxa are found in the Sierra de la Laguna pine-oak forests. The Red-spotted Toad (Anaxyrus punctatus) is one anuran found here. The widely distributed California Chorus Frog (Pseudacris cadaverina) is another resident of the ecoregion. One other anuran, Pseudacris regilla, was previously recognized in the ecoregion, but erecent DNA analysis has rendered this taxon of unclear distribution.
Of the approximately 30 mammalian species of mammals present, one of them (an endemic bat) lives only in pine-oak forests. The level of endemism is high, and this is well demonstrated by the proportion of endemic species with respect to total recorded species. More than ten percent of the mammalian species found at Sierra de la Laguna are endemic. One notable mammal found along the far west coast, including California and Baja, is the Ornate Shrew (Sorex ornatus). There are several threatened mammals found in the Sierra de la Laguna pine-oak forests, including: the Mexican Long-tongued Bat (Choeronycteris mexicana NT). The isolation of this region has contributed to the scarcity of predators, and to the poor competitive ability of some animals. Rodents and lagomorphs are virtually absent from the region
The avifauna inhabiting these pine-oak forests is important because half of the bird species breeding at Sierra de la Laguna only utilize pine-oak forests as breeding habitat. The endemic Baja Pygmy Owl (Glaucidium gnoma hoskinsii), along with the White-winged Dove (Zenaida asiatica) and Golden Eagle (Aquila chrysaetos) are only a few of the avian species found in this ecoregion. Other notable birds in this and the Gulf of California xeric scrub ecoregion include the Xantus's Hummingbird (Hylocharis xantusii) and the endangered Peninsular Yellowthroat (Geothlypis beldingi EN)..
Habitat and Ecology
Comments: Habitats are diverse and include grassland, chaparral, oak woodland, and open pine forest; in drier regions, the species most often occurs along streams or in other moist, vegetated areas (Stebbins 2003). Microhabitats include logs, thickets, rocks, and old woodpiles and trash heaps around houses (Stebbins 2003). This is a basically terrestrial lizard that sometimes climbs bushes and trees. Egg-laying sites include burrows or stable talus (Nussbaum et al. 1983).
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Comments: Eats a wide variety of invertebrates including: slugs, insects, centipedes, scorpions, and spiders. Also eats small vertebrates: lizards, small mammals, and occasionally eggs and young of birds (Stebbins 1985).
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: > 300
Comments: Known from hundreds of locations. Nussbaum et al. (1983) mapped about 90 localities in Washington and Oregon, and Lais (1976) mapped hundreds of collection sites throughout much of California.
100,000 to >1,000,000 individuals
Comments: Total adult population size is unknown but surely exceeds 100,000.
Sometimes enters water to escape predators. Eurythermic during activity (J. Herpetol. 27:241-247).
Life History and Behavior
Comments: Inactive during the coldest weather, but active over a wide range of temperatures (body temperatures of about 9-34 C) (Kingsbury, 1994, Herpetologica 50:266-273). Primarily diurnal, except during warmer parts of the year when it may be partly nocturnal (Stebbins 1985).
Lifespan, longevity, and ageing
Lays 1-3 clutches May-July (Stebbins 1985). Clutch size varies with the size of the female but usually is 5-20. Hatchlings emerge around September or October (Nussbaum et al. 1983).
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Intrinsic Vulnerability: Moderately vulnerable
Global Short Term Trend: Relatively stable (=10% change)
Comments: The trend in extent of occurrence, area of occupancy, and abundance is likely relatively stable, with localized declines not posing a threat to the species.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Degree of Threat: Medium
Comments: Commercial and residential development have caused localized declines, but many populations exist in remote areas, and the species is tolerant of a modest amount of habitat alteration.
Global Protection: Very many (>40) occurrences appropriately protected and managed
Southern Alligator Lizard
The Southern alligator lizard (Elgaria multicarinata) is a lizard native to the Pacific coast of North America. It is common throughout Southern California and can be found in grasslands, chaparral, and forests as well as urban areas. In dry climates, it is likely to be found in moist areas or near streams. Three subspecies can be distinguished: the California alligator lizard (E. m. multicarinata), the San Diego alligator lizard (E. m. webbii), and the Oregon alligator lizard (E. m. scincicauda).
The southern alligator lizard has a long, somewhat prehensile tail, up to twice the length of its body. Like many lizards, however, it can drop its tail if attacked, possibly giving it a chance to flee; the tail will regenerate, but will never be as long or richly colored as the original. Individuals with intact tails can reach up to about 11in total length.
The lizards can frequently be found near human habitation and are notable for their fearless self-defense; they will often bite and defecate if handled. In the wild they eat small arthropods, slugs, lizards, small mammals and occasionally young birds and eggs.
Elgaria multicarinata subsp. webbii (Baird, 1859); Yosemite National Park
Southern alligator lizard, Central Valley
Names and Taxonomy
Comments: Elgaria multicarinata formerly was included in the genus Gerrhonotus (see Good 1988).
A molecular phylogeographic study of Feldman and Spicer (2006) failed to support currently recognized subspecies boundaries within E. multicarinata.
Populations along the central Baja California coast, formerly included in this species, were reassigned to E. paucicarinata (Grismer 1988). Some authors have suggested that E. multicarinata and E. paucicarinata should be considered conspecific; however, Good (1988) concluded that paucicarinata is more closely allied with E. kingii.
Five intergrading subspecies have been recently recognized: ingava, multicarinata, nana, scincicauda, and webbii).
Molecular data support recognition of the family Anniellidae and anguid subfamilies Gerrhonotinae and Anguinae as monophyletic groups (Macey et al. 1999).
See Good (1988) for taxonomic treatments of gerrhonotine lizards.