Geography 316: Biogeography
In progress
12/16/2003
Geography 316: Biogeography
In progress
12/16/2003
The Biogeography of the Northern Alligator
Lizard.
Elgaria coerulea
by Steve Wong, student in
Geography 316 Fall 2003
Thank you for visiting our site. This web page was written by a student in
Geography 316: Biogeography and edited by the instructor, Barbara Holzman, PhD.
All photos and maps are posted with specific copyright permission for the
express use of education on these web pages. The students have tried to be as
accurate as possible with the information provided and sources and references
are cited at the end of each page.
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Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Family: Anguidae Genus: Elgaria Species: Elgaria coerulea
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Description of Species:
Elgaria coerulea, or the Northern alligator lizard, is roughly 2.5 inches to 5.5 inches or the general length of the hand to shorter. The cross section width is about the size of dime or quarter. A Slender body crossed with horizontal bands of different colored scales mark are very typical, with a few not having bands at all. Gray, brown, tan, bluish, reddish in color back with a lighter or different colored under belly, but be careful in trying to turn one over, they give a bit of a nippin, and from first hand experience, they have micro teeth that are a bit uncomfortable. The tail is long and falls off easily if disturbed (Stebbins 2003).
Elgaria coerulea (California Herps 2003).
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Subspecies
There are four different subspecies of the Elgaria coerulea in the western portion of the United States, each with a different region. The San Francisco alligator lizard, Elgaria coeruela coerulea, has irregular horizontal bands on the back and scales are usually heavily keeled on sides and back. The Shasta alligator lizard, Elgaria coerulea shastensis, has smooth temporals and or head might be gray with a tan colored body. The Northwestern alligator lizard (some time refered to as just Northern alligator lizard e.g. Wasserman 1971), Elgaria coerulea principis, is smaller in size usually in the 4 inch range, large tan stripe on side, colors vary from olive, tan, gray to brown. The Sierra alligator lizard, Elgaria coerulea palmeri, has horizontal markings on back, sides, or none at all.(Stebbins 1966)
Natural History:
This lizard is thought to be diurnal in nature, basking in the sun to regulate its body temperature which is kept at a 20-30 degrees Celsius (68-86 degrees Fahrenheit)(Vitt 1973). Their main habitat is woodland and forest like landscapes, but also can be found in grassland, and brush habitat. These lizards like cooler, damper places such as under rock, logs, bark, and any type of debris, but will often be found on warm surfaces like other lizards (Stebbins 2003). Yet Alligator lizards do not seem to be restricted to one area or habitat. In Rutherford and Gregory (2001) it describes the occurrence of the lizard in a variety of settings and ecosystems such as riparian zones, wetlands, mixed coniferous, deciduous, arbutus forests, meadows and flood plains.
Picture 1 is of Contra Costa County, 2 Marin County, 3 Monterey County (California Herps 2003).
Seasonal habitat
Alligator lizards tend to like cool temperature. This is the reason that some propose the reptile’s occurrence in high elevations. They are active all year with the exception of winter where they hibernate. Lizards found away from temperate conditions in winter, hibernate for extended periods of time, with little time during the other seasons to breed, eat, and become active (Smith 1946).
Reproduction
Mating season occurs from April through July, pending weather conditions. Mating rituals involve various playing such as, neck biting and copulation up to 24 hours (Morey 2003). This is a lizard that bears live young, typically 2-15 in litter (Stebbins 2003).
(Stebbins 1966)
Evolution:
Lizard ancestors can be traced back to as far as the late Carboniferous period, 300 million years ago (Campbell 1999). The ancestors to the reptiles were amphibians known as the Devonian. An important factor that separated reptiles from amphibians and allowed them to radiate off was the process of internal fertilization. Soft eggs in water suited amphibian reproduction adequately, but the development of a hardened egg shell for land required sperm to enter the egg before hardening. The early reptiles adapted this trait to be able to carry young onto terrestrial environment (Mattison 1999).
Two major radiations of reptiles occurred during the Paleozoic era, the synapsids and the sauropsids. The sauropsids gave rise to lizards, snakes, turtles, dinosaurs and others (see figure), the synaosids to the future mammals (Campbell 1999).
The top graph is of from Mattison 1999 and the second is from Campbell 1999.
Today there are three orders of reptiles, the turtles (Chelonia), lizard and snakes (Squamata), and alligator and crocodiles (Crocodilia). In the Squamata there is three suborders, the snakes, lizards, and amphisbaenas (Tyning 1990).
The family Anguidae is a small family sustaining about 100 species (Pianka 2003). They are widely distributed throughout the world ranging from the Americas, to Europe and Asia, as well as other regions around the world. This family is varied with a number of distinct groupings (Mattison 1999). Most anguids have armor like scales and tendency to lose limbs (over an evolutionary time scale). This family has live-bearing and egg laying mothers even in the same genus (Mattison 1999).
Distribution:
Distribution
The Northern alligator lizard range starting from the north is Southern British Columbia, Vancouver Island, Washington state, Oregon, Northern California: from the coasts to the Cascade Mountains, Sierra Nevada Mountain range, Big Sur area, Kern County, Madoc County, Warner Mountain and other various areas in California. Also, the ranges east to west through Montana and north Idaho with there being other various isolated populations throughout adjacent areas (Stebbins 2003).
Black and white map from Wasserman 1971.
Color map from Stebbins 2003.
Interesting facts:
The alligator lizard has this common name cause it looks and acts like a small alligator (Smith 1946)
Alligator lizards have live bearing young, very atypical of lizards and reptiles (Mattison 1999).
“Copulating lizards were found to be unresponsive to human presence, even tolerated being picked up while they remained together” (Rutherford 2001).
The word “coeruleus” in Latin means blue and refers to the dorsal coloration found on some subspecies of Northern Alligator Lizard (Wasserman 1968).
Bibliography
California Herps. 2003. California Reptiles and
Amphibians. Electronic source. (http://www.californiaherps.com/lizards/pages/e.c.coerulea.html).
December 6, 2003.
Campbell, Neil A., Reece, Jane B., and Lawrence G, Mitchell. 1999. Biology. California. Addison Wesley Longman.
Cockran, Doris M. and Goin, Coleman J. 1970. Reptiles and Amphibians. New York. G.P. Putnam’s Sons.
Cossel, John. 1997. Electronic source. (http://imnh.isu.edu/digitalatlas/bio/reptile/lacer/elco/elco.htm). October 15, 2003.
Feldman, Christoffer R. 2000. Comparative Phylogeography of three California Reptiles: Contia tenuis, Diadophis punctatus, Elgaria multicarinata. Masters Thesis, San Francisco State University, May 2000.
Mattison, Chris. 1999. Lizards of the World. New York. Sterling Publishing.
Morey, S. California Department of Fish and Game California Interagency Wildlife Task Group. California Wildlife Habitat Relationships System. Electronic source. (http://www.dfg.ca.gov/whdab/html/R042.html). October 15, 2003.
National Wildlife Federation. Electronic source. (http://www.enature.com/fieldguide/showSpeciesGS.asp?sort=1&curGroupID=99&display=1&area=99&searchText=alligator+lizard&curPageNum=2&recnum=AR0182). October 15, 2003.
Pianka, Eric R. And Vitt, Laurie J. 2003. Lizards: Windows to the Evolution of Diversity. University California Press Berkeley and Los Angeles.
Pope, Clifford H. 1955. The Reptile World; A Natural History of the Snakes, Lizards, Turtles and Crocodilians. New York. Alfred A. Knopf
Rutherford, Pamela L. And Patrick T, Gregory. 2001 Habitat use and Movement Patterns of Northern Alligator Lizards and Western Skinks in Southeastern British Columbia. Electronic Source. (http://www.cbfishwildlife.org/reports/pdfs/gatorskink01.pdf) December 6, 2003.
Stebbins, Robert C. 2003. A Field Guide to Western Reptiles and Amphibians. New York, New York.. Houghton Milflins Company.
Stebbins, Robert C. 1985. A Field Guide to Western Reptiles and Amphibians. New York, New York.. Houghton Milflins Company.
Stebbins, Robert C. 1966. A Field Guide to Western Reptiles and Amphibians. New York, New York. Houghton Milflins Company.
Smith, Hobart. 1946. Lizards of the United States and Canada. New York. Comstock Publishing Company Inc.
Tyning, Thomas F. 1990. A Guide to Amphibians and Reptiles. New York. Little Brown Company.
Vitt, L. J. 1973. Reproductive
biology of the anguid lizard, gerrhonotus coeruleus principis.
Herpetologica 29:176-184.
Wasserman, Aaron O. 1971. Catalogue of American Amphibians and Reptiles. New York. American Society of Ichthyologists and Herpetologist.
Links:
These links pertain to the genus Elgaria, family Anguidae, or species Elgaria Coerulea.
pictures and references
http://www.wildherps.com/species/E.coerulea.html
Basic info and pictures
http://yahooligans.yahoo.com/content/animals/species/4322.html
http://www.enature.com/fieldguide/showSpeciesRECNUM.asp?RECNUM=AR0055
http://www.nature.ca/notebooks/english/allizard.htm
http://jlpuhn.tripod.com/Lizards/nalligator.html
http://www.fs.fed.us/psw/rsl/projects/wild/verner/amphibians_reptiles/r010.pdf
http://www.montereybay.com/creagrus/CAalligatorlizards.html
http://kaweahoaks.com/html/alligator_lizard.htm
Info on Idaho
http://imnh.isu.edu/digitalatlas/bio/reptile/lacer/elco/elco.htm
Text and references
http://www.dfg.ca.gov/whdab/html/R042.html
Habitat use and migration patterns
http://www.cbfishwildlife.org/reports/pdfs/gatorskink01.pdf
Photos
http://jlpuhn.tripod.com/Lizards/nalligator.html
http://www.californiaherps.com/lizards/pages/e.c.coerulea.html
http://elib.cs.berkeley.edu/photos/fauna/sci-Reptile.html
Taxonomy
http://www.embl-heidelberg.de/~uetz/families/taxa.html#Sau
send comments to
bholzman@sfsu.edu
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