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Montana Field Guides

Northern Alligator Lizard - Elgaria coerulea

Species of Concern
Native Species

Global Rank: G5
State Rank: S3

Agency Status

External Links

General Description
The body of the Northern Alligator Lizard is elongate and the legs are short. The back is brown, tan, or gray to olive, yellow, or greenish. The dark sides of the body are often checkered with small darker patches. The belly scale rows are edged with a darker area giving the white to pale gray belly a banded appearance. There is a distinctive fold of skin running along each side of the body extending between the legs, revealing small granular scales when spread apart. Males have larger and broader triangular-shaped heads; juveniles have a broad reddish-tan stripe running the length of the back. Adults of E. c. principis are 7 to 10 centimeters snout-vent length (SVL) and up to 20 centimeters in total length; newly born young are about 2.5 to 3.0 centimeters snout-vent length.

Species Range
Montana Range Range Descriptions


Western Hemisphere Range


Observations in Montana Natural Heritage Program Database
Number of Observations: 168

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

No information is currently available.

There is little specific information on habitat associations in Montana. Several observations have been made on south-facing slopes in fine to course talus, sometimes in the open, but often with some canopy cover of Douglas-fir, ponderosa pine, a variety of shrubby species (serviceberry, ninebark, mock orange), and a litter layer of dried leaves and conifer needles (Werner and Reichel 1994, Hendricks and Reichel 1996, Werner et al. 1998, Boundy 2001).

From other locations within the species' range, the Northern Alligator Lizard occurs in areas more cool and humid than most lizards tolerate, but it also appears to require some sunny clearings. It is found in coniferous forest, often in grassy grown-over areas at the margins of woodlands, in clearcuts, sometimes near streams or in sagebrush habitats, along coasts sometimes far from trees or major cover, often associated with rock outcrops and talus in some regions, and frequenting areas around abandoned buildings (Lais 1976, Nussbaum et al. 1983, St. John 2002, Stebbins 2003).

Ecological Systems Associated with this Species
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.  If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2012.  Mammals of Montana.  Second edition.  Mountain Press Publishing, Missoula, Montana.  429 pp.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Food Habits
An invertivore, Northern Alligator Lizards feed on insects, ticks, spiders, centipedes, millipedes, slugs and snails (Nussbaum et al. 1983, St. John 2002, Stebbins 2003). There is no information on the food habits of this species in Montana.

Limited information is available for Montana. The Northern Alligator Lizard is a secretive species, most often found under logs and rocks, although it is frequently detected rustling through litter of dried leaves and needles or sunning in an exposed location. The life history has not been thoroughly studied. Northern Alligator Lizards are active during the day, after emerging from winter hibernation, from April to September (Nussbaum et al. 1983, St. John 2002, Stebbins 2003). Animals have been found surface active in Montana from early April through September (Rodgers and Jellison 1942, Werner and Reichel 1994, Hendricks and Reichel 1996, Boundy 2001); hibernacula in Montana are not described. There is little information on the predators of this species, but they readily drop their tails, and tails have been found in stomachs of snakes (Nussbaum et al. 1983). There are no reports of predation on this species in Montana.

On the Washington coast body temperature ranged from 20 to 30 degrees C. and correlated with substrate temperature. Males basked during the height of spermatogenesis. Basking may be especially important in high elevation populations.

Reproductive Characteristics
No information is available specific to Montana. Based upon information from other locations the species apparently mates in April and May. One litter per year is produced, with litter size varying depending on the geographic locality (3 to 8 in the Seattle, Washington area, and 2 to 6 on the central Oregon coast, with a mean of 4 in both localities). Young are born live in about three months after eggs are fertilized (June to September). Females reach sexual maturity in 32 to 44 months in northern California (Nussbaum et al. 1983, St. Johns 2002, Stebbins 2003).

Limited survey data available indicate that populations are widespread and rare, but may be locally abundant in some areas of extensive talus slopes in western Montana. Research and management recommendations in Montana's Amphibian and Reptile Conservation Plan (Maxell et al. 2009) include: (1) focal surveys in potential habitat across northwestern Montana; (2) studies of habitat use and population dynamics are needed, especially as they relate to livestock grazing, timber harvest, and agricultural practices; (3) ground cover of rocks and woody debris should be maintained in occupied areas where timber harvest and other management actions are undertaken; (4) the direct and indirect impacts of insecticides, herbicides, and insect pest control agents used in weed and pest control programs need to be assessed, as use of these chemicals and insect agents could impact populations by eliminating prey or through direct poisoning; and (5) studies of the impacts of exotic weed species (e.g., spotted knapweed and cheatgrass) should be undertaken.

  • Literature Cited AboveLegend:   View Online Publication
    • Boundy, J. 2001. Herpetofaunal surveys in the Clark Fork Valley region, Montana. Herpetological Natural History 8: 15-26.
    • Hendricks, P. and J.D. Reichel. 1996a. Amphibian and reptile survey of the Bitterroot National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 95 p.
    • Lais, P. M. 1976. Gerrhonotus coeruleus. Catalogue of American Amphibians and Reptiles 178.1-178.4.
    • Maxell, B.A., P. Hendricks, M.T. Gates, and S. Lenard. 2009. Montana amphibian and reptile status assessment, literature review, and conservation plan, June 2009. Montana Natural Heritage Program. Helena, MT. 643 p.
    • Nussbaum, R.A., E.D. Brodie, Jr. and R.M. Storm. 1983. Amphibians and reptiles of the Pacific Northwest. University of Idaho Press. Moscow, ID. 332 pp.
    • Rodgers, T. L. and W. L. Jellison. 1942. A collection of amphibians and reptiles from western Montana. Copeia (1):10-13.
    • St. John, A.D. 2002. Reptiles of the northwest: California to Alaska, Rockies to the coast. Lone Pine Publishing, Renton, WA. 272 p.
    • Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. 3rd Edition. Houghton Mifflin Company, Boston and New York. 533 p.
    • Werner, J.K. and J.D. Reichel. 1994. Amphibian and reptile survey of the Kootenai National Forest: 1994. Montana Natural Heritage Program. Helena, MT. 104 p.
    • Werner, J.K., T. Plummer, and J. Weaslehead. 1998a. Amphibians and reptiles of the Flathead Indian Reservation. Intermountain Journal of Sciences 4(1-2): 33-49.
  • Additional ReferencesLegend:   View Online Publication
    Do you know of a citation we're missing?
    • Avise, J.C., B.W. Bowen, T. Lamb, A.B. Meylan, and E. Birmingham. 1992. Mitochondrial DNA evolution at a turtle's pace: evidence for low genetic variability and reduced microevolutionary rate in the Testudines. Molecular Biological Evolution 9:457-473.
    • Banta, B.H., C.R. Mahrdt, and K.R. Beaman. 1996. Reptilia: Squamata: Sauria: Anguidae: Elgaria panamintina. Catalogue of American Amphibians and Reptiles 629.1-629.4
    • Boundy, J. and T.G. Balgooyen. 1988. Record lengths for some amphibians and reptiles from the western United States. Herpetological Review 19(2): 26-27.
    • Bowker, R.W. 1987. Elgaria kingi (arizona alligator lizard). Aantipredator behavior. Herpetological Review 18(4): 73, 75.
    • Bowker, R.W. 1988a. A comparative behavioral study and taxonomic analysis of Gerrhonotine lizards. Ph.D. Dissertation, Arizona StateUniversity 139p. 1988.
    • Bowker, R.W. 1988b. Comparative courtship behavior of Gerrhonotine lizards. Journal of the Arizona-Nevada Academy of Science 23(Suppl.): 13.
    • Bowker, R.W. 1994a. Elgaria kingi (arizona alligator lizard). Size. Herpetological Review 25(3): 121.
    • Brunson, R.B. 1955. Check list of the amphibians and reptiles of Montana. Proceedings of the Montana Academy of Sciences 15: 27-29.
    • Brunson, R.B. and H.A. Demaree, Jr. 1951. The herpetology of the Mission Mountains, Montana. Copeia (4):306-308.
    • Cooper, W.E. 1990b. Prey odor discrimination by anguid lizards. Herpetologica 46(2): 183-190.
    • Cooper, W.E., Jr. 1995. Strike-induced chemosensory searching by the anguid lizard Elgaria coerulea. Amphibia-Reptilia 16(2):147-156.
    • Cope, E.D. 1875. Check-list of North American Batrachia and Reptilia; with a systematic list of the higher groups, and an essay on geographical distribution. Based on the specimens contained in the U.S. National Museum. U.S. Natioanl Museum Bulletin 1: 1-104.
    • Criley, B.B. 1986. The cranial ostelogy of gerrhonotiform lizards. American Midland Naturalist 80:199-219.
    • Crother, B.I. (ed.) 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico. SSAR Herpetological Circular No. 37:1-84.
    • Farmer, P. and S.B. Heath. 1987. Wildlife baseline inventory, Rock Creek study area, Sanders County, Montana. Western Technology and Engineering, Inc. Helena, MT.
    • Fitch, H.S. 1934a. A shift of specific names in the genus Gerrhonotus. Copeia 1934: 172-173.
    • Fitch, H.S. 1934b. New alligator lizards from the Pacific Coast. Copeia 1934: 6-7.
    • Fitch, H.S. 1935. Natural history of the alligator lizards. Transactions of the Academy of Sciences in St. Louis 29: 1-38, 4 pls.
    • Fitch, H.S. 1938. A systematic account of the alligator lizards (Gerrhonotus) in the western United States and lower California. American Midland Naturalist 20: 381-424.
    • Franz, R. 1971. Notes on the distribution and ecology of the herpetofauna of northwestern Montana. Bulletin of the Maryland Herpetological Society 7: 1-10.
    • Freeman, D.M., D.K. Hendrix, D. Shah, L.F. Fan, and T.F. Weiss. 1993. Effect of lymph composition on an in vitro preparation of the alligator lizard cochlea. Hearing Research 65(1-2): 83-98.
    • Goldberg, S.R. and C.R. Bursey. 1991c. Gastrointestinal helminths of the northwestern alligator lizard, Gerrhonotus coeruleus principis (Anguidae). Journal of the Helminthological Society of Washington 58(2): 246-248.
    • Good, D.A. 1985. Studies of interspecific and intraspecific variation in the alligator lizards (Lacertillia: Anguidae: Gerrhonotinae). Ph.D. Dissertation. University of California at Berkeley, Berkeley, CA. 622 p.
    • Good, D.A. 1987b. An allozyme analysis of anguid subfamilial relationships (Lacertilia: anguidae). Copeia 1987(3): 696-701.
    • Good, D.A. 1988a. Allozyme variation and phylogenetic relationships among the species of Elgaria (Squamata: Anguidae). Herpetologica 44: 154-162.
    • Good, D.A. 1988b. Phylogenetic relationships among gerrhonotine lizards: an analysis of external morphology. University of California Publications in Zoology 121: 1-139.
    • Good, D.A. Cranial ossification in the northern alligator lizard, Elgaria coerulea (Squamata, Anguidae). Amphibia-Reptilia 16(2): 157-166.
    • Gregory, P. T. and R. W. Campbell. 1984. The reptiles of British Columbia. British Columbia Provincial Museum, Victoria, British Columbia, Canada. 102 pp.
    • Grismer, L.L. 1988. Geographic variation, taxonomy, and biogeography of the anguid genus Elgaria (reptilia: squamata) in Baja California, Mexico. Herpetologica 44(4): 431-439.
    • Hanauska-Brown, L., B.A. Maxell, A. Petersen, and S. Story. 2014. Diversity Monitoring in Montana 2008-2010 Final Report. Montana Fish, Wildlife & Parks. Helena, MT. 78 pp.
    • Hendricks, P. 1997. Lee Metcalf National Wildlife Refuge preliminary amphibian and reptile investigations: 1996. Montana Natural Heritage Program, Helena, MT. 21 p.
    • Joslin, Gayle, and Heidi B. Youmans. 1999. Effects of recreation on Rocky Mountain wildlife: a review for Montana. [Montana]: Montana Chapter of the Wildlife Society.
    • Kingsbury, B.A. 1992. The thermal ecology of the southern alligator lizard, Elgaria multicarinata. Ph.D. Dissertation, University of California (Riverside); 119p. 1991.
    • Kingsbury, B.A. 1993. Thermoregulatory set points of the eurythermic lizard Elgaria multicarinata. Journal of Herpetology 27(3): 241-247.
    • Kingsbury, B.A. 1994b. Thermal constraints and eurythermy in the lizard Elgaria multicarinata. Herpetologica 50(3): 266-273.
    • Kingsbury, B.A. 1995. Field metabolic rates of a eurythermic lizard. Herpetologica 51(2): 155-159.
    • Loeza-Corichi, A. and O. Flores-Villela. 1995. Elgaria kingii (madrean alligator lizard). Herpetologial Review 26(2): 108.
    • Macey, J. R., J. A. Schulte, II, A. Larson, B. S. Tuniyev, N. Orlov, and T. J. Papenfuss. 1999. Molecular phylogenetics, tRNA evolution, and historical biogeography in anguid lizards and related taxonomic families. Molecular Phylogenetics and Evolution 12:250-272.
    • Maxell, B.A. 2009. State-wide assessment of status, predicted distribution, and landscapelevel habitat suitability of amphibians and reptiles in Montana. Ph.D. Dissertation. Missoula, MT: Wildlife Biology Program, University of Montana. 294 p.
    • Maxell, B.A., J.K. Werner, P. Hendricks, and D.L. Flath. 2003. Herpetology in Montana: a history, status summary, checklists, dichotomous keys, accounts for native, potentially native, and exotic species, and indexed bibliography. Society for Northwestern Vertebrate Biology, Northwest Fauna Number 5. Olympia, WA. 135 p.
    • Northrop, Devine & Tarbell, Inc. 1994. Cabinet Gorge and Noxon Rapids hydroelectric developments: 1993 wildlife study. Unpublished report to the Washington Water Power Company, Spokane. Vancouver, Washington and Portland, Maine. 144 pp. plus appendices.
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    • Rutherford, P.L. and P.T. Gregory. 2003a. Habitat use and movement patterns of northern alligator lizards (Elgaria coerulea) and western skinks (Eumeces skiltonianus) in southeastern British Columbia. Journal of Herpetology 37: 98-106.
    • Rutherford, P.L. and P.T. Gregory. 2003b. How age, sex, and reproductive condition affect retreat-site selection and emergence patterns in a temperate-zone lizard, Elgaria coerulea. Ecoscience 10(1):24-32.
    • Smith, H.M. 1986. The generic allocation of two species of mexican anguid lizards. Bulletin of the Maryland Herpetological Society 22(1): 21-22. 1986.
    • Spengler, J.C. and H.M. Smith. 1983 Intact exuviae in lizards. Bulletin of the Maryland Herpetological Society 19(1) :24-26.
    • Stebbins, R.C. 1958. A new alligator lizard form the Panamnit Mountains, Inyo County, California. American Museum of Novitates 1883:1-27.
    • Stewart, J.R. 1985. Growth and survivorship in a California population of Gerrhonotus coerulens, with comments on intraspecific variation in adult female size. American Midland Naturalist 113: 30-44.
    • Storm, R. M., and W. P. Leonard (eds.). 1995. Reptiles of Washington and Oregon. Seattle Audubon Society. Seattle, WA. 176 pp.
    • Svihla, A. 1942. Mating behavior of the northern alligator lizard. Copeia 1942(1): 52.
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    • Tihen, J.A. 1949. The genera of gerrhonotine lizards. American Midland Naturalist 41(3): 580-601.
    • Timken, R. No Date. Amphibians and reptiles of the Beaverhead National Forest. Western Montana College, Dillon, MT. 16 p.
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    • Werner, J.K. and J.D. Reichel. 1996. Amphibian and reptile monitoring/survey of the Kootenai National Forest: 1995. Montana Natural Heritage Program. Helena, MT. 115 pp.
    • Werner, J.K. and T. Plummer. 1995a. Amphibian and reptile survey of the Flathead Indian Reservation 1993-1994. Salish Kootenai College, Pablo, MT. 55 pp.
    • Werner, J.K. and T. Plummer. 1995b. Amphibian monitoring program on the Flathead Indian Reservation 1995. Salish Kootenai College, Pablo, MT. 46 p.
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Northern Alligator Lizard — Elgaria coerulea.  Montana Field Guide.  .  Retrieved on , from