The northern alligator lizard (''Elgaria coerulea'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of medium-sized

lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic isla ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Anguidae. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

n west coast.

Taxonomy

The northern alligator lizard was formerly known by the scientific name of ''Gerrhonotus coeruleus'' , but more recently has been assigned to the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Elgaria''.

Subspecies

Four

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognized as being valid, including the

nominotypical subspecies In biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. ...

.. www.reptile-database.org. *''E. c. coerulea'' – San Francisco alligator lizard *''E. c. palmeri'' – Sierra alligator lizard *''E. c. principis'' – Northwestern alligator lizard *''E. c. shastensis'' – Shasta alligator lizard A trinomial authority in parentheses indicates that the subspecies was originally described in a genus other than ''Elgaria''. The subspecies ''E. c. principis'' is one of seven species of lizards in Canada.

Etymology

The subspecific name, ''palmeri'', is in honor of American zoologist Theodore Sherman Palmer.

Description

The northern alligator lizard is a medium-sized slender lizard. Adults reach a snout-to-vent length (SVL) of about and a total length (including tail) of roughly . It has a distinct skin fold on each side, separating the keeled scales on the back from the smooth ventral scales. The skin varies in color, but can be brown and white, or greenish yellow and brown. Dorsally, ''E. coerulea'' is brownish in color and often has 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.

Diet

The typical diet of ''E. coerulea'' includes crickets, slugs, beetles, spiders, and moths, but it will also take larger prey, such as small lizards, and will even eat small baby mice if given the opportunity.

Reproduction

The northern alligator lizard is live-bearing, producing up to 15 young (typically 4–5), between June and September. During the spring breeding season, a male lizard grasps 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.

Distribution

The northern alligator lizard occurs along the

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

Coast and in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

from southern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

through Washington, northern

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

and western

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

south through

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

to the coastal range and the Sierra Nevada in central

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

. As the map shows, the different subspecies have quite different geographic ranges, with ''E. c. principis'' being the most widely distributed, whereas ''E. c. coerulea'' occurs mainly around the

San Francisco San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...

area but is also found farther north into Humboldt County. The species is widely distributed along the Pacific coast and can be found from sea level up to elevation of about . It is found in a variety of forested habitats and montane

chaparral Chaparral ( ) is a shrubland plant plant community, community found primarily in California, southern Oregon, and northern Baja California. It is shaped by a Mediterranean climate (mild wet winters and hot dry summers) and infrequent, high-intens ...

. As winter sets in, colder temperatures force northern alligator lizards to undergo brumation. Brumation allows them to reduce caloric usage and retain body heat during winter. Often, western alligator lizards choose to hide under rocks—though logs and burrows are occasionally used—to undergo this process.

References

External links

Images
from Californiaherps.com

from the California Department of Fish and Game.
Taxonomical Information

from the British Columbia Ministry of Environment {{Taxonbar, from=Q3176533 Elgaria Fauna of the California chaparral and woodlands Fauna of the San Francisco Bay Area Fauna of the Sierra Nevada (United States) Reptiles of Canada Reptiles of the United States Reptiles described in 1828 Taxa named by Arend Friedrich August Wiegmann