Gyalopion canum
(Cope, 1860)
Chihuahuan Hook-nosed Snake
G5SecureGlobal Rank
Least concernIUCN
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.104364
Element CodeARADB16010
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassReptilia
OrderSquamata
FamilyColubridae
GenusGyalopion
Other Common NamesWestern Hooknose Snake (EN)
Concept ReferenceHardy, L. M. 1976. Gyalopion, G. canum, G. quadrangularis. Catalogue of American Amphibians and Reptiles 182.1-182.4.
Taxonomic CommentsThis species was sometimes placed in the genus Ficimia in older literature. The previous standard English names of Ficimia and Gyalopion were misleading relative to their geographic ranges. All are distributed in Mexico, but Ficimia had the moniker "Mexican," whereas Gyalopion had the name "Plateau," yet is clearly not confined to any plateau. Given that Ficimia has the easternmost distribution, Crother (2017) call it "Eastern" and call Gyalopion "Western."
Conservation Status
Review Date2005-09-08
Change Date1996-10-30
Edition Date2005-09-08
Edition AuthorsHammerson, G.
Threat ImpactLow
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Range Extent CommentsThe range extends from southeastern Arizona, New Mexico, and western Texas south to Zacatecas and San Luis Potosi, Mexico (Hardy 1976, Ernst and Ernst 2003, Stebbins 2003). Elevational range is around 305-2,100 meters (1,000-6,890 feet) (Degenahrdt et al. 1996, Stebbins 2003).
Occurrences CommentsThis species is represented by many occurrences or subpopulations. Degenhardt et al. (1996) mapped more than 50 collection sites in New Mexico. Werler and Dixon (2000) mapped several dozen collection sites in Texas.
Threat Impact CommentsNo major threats have been identified.
Ecology & Habitat
Habitat
Habitat of this semifossorial snake consist primarily of grassy foothills (Degenhardt et al. 1996), but the species also occurs in lower desert communities (e.g., mesquite, mesquite-creosotebush, creosotebush-agave) and in higher elevations with persimmon-shin oak, oak-juniper savanna and woodland, and pinyon-juniper woodland (Degenhardt et al. 1996, Werler and Dixon 2000, Ernst and Ernst 2003, Stebbins 2003). At the northern limit of the range at the base of the Texas Panhandle, it occupied flat to rolling prairie grassland with gypsum and limestone outcroppings (Ferguson 1965). This species occurs in areas of loose soil, which may be rocky but may not include mcuh sand or gravel (Ernst and Ernst 2003).
Reproduction
Clutch size 1-4; captives have laid eggs in June and July; it is likely that not all females produce eggs each year (Goldberg 2002).
Terrestrial HabitatsWoodland - HardwoodWoodland - ConiferWoodland - MixedShrubland/chaparralSavannaGrassland/herbaceousDesert
Other Nations (1)
United StatesN5
| Province | Rank | Native |
|---|
| Arizona | S3 | Yes |
| Texas | S5 | Yes |
| New Mexico | S4 | Yes |
References (15)
- Collins, J. T. 1990. Standard common and current scientific names for North American amphibians and reptiles. 3rd ed. Society for the Study of Amphibians and Reptiles. Herpetological Circular No. 19. 41 pp.
- Conant, R. 1975. A Field Guide to Reptiles and Amphibians of Eastern and Central North America. Second Edition. Houghton Mifflin Company, Boston, Massachusetts. xvii + 429 pp.
- Crother, B. I. (editor). 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37:1-84. Online with updates at: http://www.ssarherps.org/pages/comm_names/Index.php
- Crother, B. I. (editor). 2012. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 7th edition. SSAR Herpetological Circular 39:1-92.
- Crother, B. I. (editor). 2017. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. 8th edition. SSAR Herpetological Circular 43:1-104. [Updates in SSAR North American Species Names Database at: https://ssarherps.org/cndb]
- Degenhardt, W. G., C. W. Painter, and A. H. Price. 1996. Amphibians and reptiles of New Mexico. University of New Mexico Press, Albuquerque. xix + 431 pp.
- Ernst, C. H., and E. M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
- Ferguson, G. W. 1965. Verification of a population of <i>Ficimia cana</i> in north-central Texas. Herpetologica 21:156-157.
- Goldberg, S. R. 2002. Reproduction in the Chihuahuan hook-nosed snake, <i>Gyalopion canum</i> (Serpentes: Colubridae). Journal of the Arizona-Nevada Academy of Science 34(2):95-97.
- Hardy, L. M. 1976. <i>Gyalopion</i>, <i>G. canum</i>, <i>G. quadrangularis</i>. Catalogue of American Amphibians and Reptiles 182.1-182.4.
- Stebbins, R. C. 1985a. A field guide to western reptiles and amphibians. Second edition. Houghton Mifflin Company, Boston, Massachusetts. xiv + 336 pp.
- Stebbins, R. C. 2003. A field guide to western reptiles and amphibians. Third edition. Houghton Mifflin Company, Boston.
- Tennant, A. 1984. The Snakes of Texas. Texas Monthly Press, Austin, Texas. 561 pp.
- Tennant, A. 1998. A field guide to Texas snakes. Second edition. Gulf Publishing Company, Houston, Texas.
- Werler, J. E., and J. R. Dixon. 2000. Texas snakes: identification, distribution, and natural history. University of Texas Press, Austin. xv + 437 pp.