|Scientific Name:||Hypsiglena torquata|
|Species Authority:||(Gunther, 1860)|
Hypsiglena gularis Tanner, 1954
|Taxonomic Notes:||There have been various arrangements of species within this genus and undoubtedly the current arrangement followed here can be expected to change again in the near future.
The populations on Isla Partida Norte, in the Gulf of California, Mexico are sometimes considered to be a separate species (Grismer 1999, 2000).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Hammerson, G.A., Frost, D.R., Santos-Barrera, G., Vasquez Díaz, J. & Quintero Díaz, G.E.|
|Reviewer/s:||Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)|
Listed as Least Concern in view of the large and probably relatively stable extent of occurrence, area of occupancy, number of subpopulations, and population size. This species is not threatened in most of its range.
|Range Description:||The species' range extends from southern British Columbia, Idaho, Utah, Colorado, and Kansas southward through the southwestern United States to southern Baja California (including Isla Partida Norte, in the Gulf of California) and Guerrero in mainland Mexico, at elevations from near sea level to around 2,650 m asl (8,700 feet) (Stebbins 2003). Reports of occurrences as far south as Costa Rica (e.g., Ernst and Ernst 2003) are incorrect (Savage 2002).|
Native:Canada; Mexico; United States
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is represented by hundreds of occurrences or subpopulations. The total adult population size is unknown but undoubtedly exceeds 100,000. The species occupies a wide range and is locally fairly common. The extent of occurrence, area of occupancy, number of subpopulations, and population size are probably relatively stable. The population in Mexico is stable.|
|Habitat and Ecology:||This snake generally inhabits arid and semi-arid plains, flats, canyons, and hillsides, usually rocky, dissected or hilly terrain with sandy or gravelly soils, including desert (e.g., creosote bush, sagebrush), prairie, foothill grassland, chaparral, thornscrub, thornforest, pinyon-juniper woodland, scrubby oak-juniper savanna, mesquite savanna, pine-hardwood woodland, and sometimes moist mountain meadows (Degenhardt et al. 1996, Hammerson 1999, Werler and Dixon 2000, Stebbins 2003). Periods of inactivity are spent under rocks or other surface cover, in crevices, or underground. In Idaho, individuals can be found under surface rocks in spring, but not in summer. It feeds on small amphibians and reptiles, and is an oviviparous species.|
|Major Threat(s):||No major threats to this species have been identified. The habitat generally tends to be unsuitable for human settlement.|
|Conservation Actions:||Many occurrences of this species are in national parks and other well-protected areas.|
Anderson, J.D. and Lidicker Jr., W.L. 1963. A Contribution of our Knowledge of the Herpetofauna of the Mexican State of Aguascalientes. Herpetologica 19(1): 40-51.
Bostic, D.L. 1971. Herpetofauna of the Pacific coast of north central Baja California, Mexico, with a description of a new subspecies of Phyllodactylus xanti. Transactions of the San Diego Society of Natural History 16: 237-264.
Crother, B.I., Boundy, J., Campbell, J.A., de Queiroz, K., Frost, D.R., Highton, R.H., Iverson, J.B., Meylan, P.A., Reeder, T.W., Seidel, M.E., Sites Jr., J.W., Taggart, T.W., Tilley, S.G. and Wake, D.B. 2000. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Society for the Study of Amphibians and Reptiles, Herpetological Circular No. 29. 82 pp.
Crother, B.I., Boundy, J., Campbell, J.A., de Quieroz, K., Frost, D., Green, D.M., Highton, R., Iverson, J.B., McDiarmid, R.W., Meylan, P.A., Reeder, T.W., Seidel, M.E., Sites Jr, J.W., Tilley, S.G. and Wake, D.B. 2003. Scientific and standard English names of amphibians and reptiles of North America north of Mexico: update. Herpetological Review 34: 196-203.
Degenhardt, W.G., Painter, C.W. and Price, A.H. 1996. Amphibians and Reptiles of New Mexico. University of New Mexico Press, Albuquerque, New Mexico. Xix + 431 pp.
Diller, L.V. and Wallace, R.L. 1986. Aspects of the life history of the desert night snake, Hypsiglena torquata deserticola: Colubridae, in southwestern Idaho. Southwestern Naturalist 31: 56-64.
Dixon, J.R. and Dean, R.H. 1986. Status of the southern populations of the night snake (Hypsiglena: Colubridae) exclusive of California and Baja California. Southwestern Naturalist 31: 307-318.
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|Citation:||Hammerson, G.A., Frost, D.R., Santos-Barrera, G., Vasquez Díaz, J. & Quintero Díaz, G.E. 2007. Hypsiglena torquata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 09 March 2014.|
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