Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This lizard ranges from southern British Columbia (including Vancouver Island) southward through western Washington and western Oregon to west-central coastal California and the central Sierra Nevada (including the east side of Lake Tahoe basin) and Washoe County, Nevada (Vindum and Arnold 1997). It also ranges southward in the Rocky Mountains to northern Idaho and western Montana. Disjunct populations occurs in several areas in south-central Oregon, northeastern Calofornia, and northwestern Nevada (Stebbins 2003). The western edge of the distribution includes some small coastal islands (Stebbins 2003). The elevational range extends from sea level to around 3,200 m (Stebbins 2003).
Distribution: Canada (S British Columbia), USA (Washington, Oregon, Utah, Idaho, Montana, California)
Type locality: “Brasilia” (in error); modified to “San Francisco, California” by STEJNEGER 1902.
Length: 33 cm
Habitat and Ecology
Comments: Habitat includes open areas in coniferous forest, grassy grown-over areas at margins of woodlands, clearcuts, and areas along streams; along coast this lizard sometimes occurs far from trees or major cover; it is associated with rock outcrops and talus in some areas (Lais 1976).
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.
Mark-recapture studies in British Columbia indicated that individuals did not make long-distance moves between summer habitat and hibernation sites (Rutherford and Gregory 2003).
Comments: Feeds on insects, ticks, spiders, millipedes, and snails.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 - 300
Comments: Nussbaum et al. (1983) mapped more than 200 locations where this species has been found.
10,000 - 1,000,000 individuals
Comments: Total adult population size is unknown but surely exceeds 10,000. The species is often fairly common in suitable habitat (St. John 2002).
Life History and Behavior
Comments: Hibernates in winter; duration of inactive period varies with local climate.
Apparently mates in April and May. Litter size averages 4-6, depending on locality. One litter per year. Females sexually mature in 32-44 months in northern California.
Molecular Biology and Genetics
Statistics of barcoding coverage: Elgaria coerulea
Public Records: 0
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
National NatureServe Conservation Status
Rounded National Status Rank: N4 - Apparently Secure
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 overall population is likely relatively stable in extent of occurrence, area of occupancy, and abundance.
Global Long Term Trend: Increase of 10-25% to decline of 30%
Comments: Likely relatively stable in extent of occurrence, area of occupancy, and abundance; there has surely been a decline in area of occupnacy and abundance, but the magnitude of the decline has been relatively small.
Degree of Threat: Medium
Comments: The primary threat may be outright destruction of habitat. The species tolerates some habitat disturbances such as logging. Nussbaum et al. (1983) stated that the introduction of the cinnabar moth for weed (tansy ragweed) control may have adverse effects on northern alligator lizards. The moths are reported to be highly poisonous to the lizards.
Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed
Comments: This species occurs in many protected areas.
Northern Alligator Lizard
This lizard was formerly known under the scientific name of Gerrhonotus coeruleus (Wiegmann, 1828), but is nowadays classed as the genus 'Elgaria'. There are four subspecies:
- E.c. coerulea Wiegmann 1828: San Francisco alligator lizard
- E.c. palmeri Stejneger 1893: Sierra alligator lizard
- E.c. principis Baird and Girard 1852: Northwestern alligator lizard
- E.c. shastensis Fitch 1934: Shasta alligator lizard
The subspecies E.c. principis is one of five species of lizards in Canada.
Northern alligator lizards are medium-sized slender lizards. Adults reach a snout-to-vent length of about 10 cm (4 inches) and a total length of roughly 27.5 cm (11 in). They have a distinct skin fold on their sides, separating the keeled scales on the back from the smooth ventral scales. this skin varies in color, but can be brown and white or greenish yellow and brown. They are brownish in color and often have dark blotches that sometimes blend together into bands. the throat and mouth area of some young individuals can be yellow. The belly is light gray. The eyes are dark. Their typical diet includes crickets, mealworms, and moths, but they will also take larger prey, such as small lizards, and will even eat small baby mice if given the opportunity.
The northern alligator lizard lays about 7-10 eggs (Not live bearers; except for E. c. coerulea, which is a live bearer), approximately 2 months after mating. Northwestern alligator lizards young are born live and fully formed sometime between June and September. During the spring breeding season, a male lizard grabs on to the head of a female with his mouth until she is ready to let him mate with her. They can remain attached this way for many hours, almost oblivious to their surroundings. Besides keeping her from running off to mate with another male, this probably shows her how strong and suitable a mate he is. ( http://www.californiaherps.com/lizards/pages/e.c.principis.html)
The Northern alligator lizard occurs along the Pacific Coast and in the Rocky Mountains from southern British Columbia through Washington, northern Idaho and western Montana south through Oregon to the coastal range and the Sierra Nevada in central California. As the map shows, the different subspecies have quite different ranges, with E.c. principis being the most widely distributed, whereas the E.c. coerulea subspecies occurs only around the San Francisco area.
The species is widely distributed along the Pacific coast and can be found from sea level up to elevation of about 3350 m (11000 ft). It is found in a variety of forested habitats and montane chaparral.
- A Field Guide to Western Reptiles and Amphibians. Stebbins, R., 2012
- Encyclopedia of Animals:Mammals,Birds,Reptiles,Amphibians
Names and Taxonomy
Comments: Elgaria coerulea formerly was included in genus Gerrhonotus (see Good 1988). Four intergrading subspecies (coerulea, palmeri, principis, and shastensis) are recognized. See Good (1988) for taxonomic treatments of gerrhonotine lizards.
Molecular data support recognition of the family Anniellidae and anguid subfamilies Gerrhonotinae and Anguinae as monophyletic groups (Macey et al. 1999).