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Diadophis punctatus

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA REPTILIA SQUAMATA DIPSADIDAE

Scientific Name: Diadophis punctatus
Species Authority: (Linnaeus, 1766)
Common Name/s:
English Ring-necked Snake, Ringneck Snake
Taxonomic Notes: This species complex is treated here as a single species until there is resolution of the current taxonomic confusion.

This species is in need of further phylogenetic and taxonomic study. Available information suggests that multiple species may be represented and that several nominal subspecies do not represent unique evolutionary lineages (see commentary in Crother et al. 2000). For example, Pinou et al. (1995) examined geographic variation in serum albumin and concluded that Diadophis may comprise at least two genetically distinct species. Populations assigned to subspecies arnyi, amabilis, and occidentalis were distinct immunologically from eastern D. p. edwardsii. They pointed out the need for additional study of the taxonomic status and relationships among the nomimal taxa within Diadophis, especially subspecies regalis and dugesii (morphological data of Gehlbach [1974, Herpetologica 30: 140-148] indicate that arnyi and regalis intergrade over a broad section of central Texas). In ongoing genetic studies, Feldman (cited by Crother et al. 2000) found that the subspecies in California (amabilis, modestus, occidentalis, pulchellus, similis, and vandenburghii) are nearly indistinguishable.

Subspecies acricus was proposed as a distinct species by Collins (1991). Collins (1991) further proposed that the species punctatus be split into two species, D. punctatus (including the subspecies arnyi, edwardsii, regalis, punctatus, and stictogenys) and D. amabilis (including the subspecies modestus, occidentalis, pulchellus, similis, and vandenburghii). However, Collins did not present supporting data, and this proposal has not been adopted by others.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2007
Date Assessed: 2007-03-01
Assessor/s: Hammerson, G.A. & Frost, D.R.
Reviewer/s: Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)
Justification:
Listed as Least Concern in view of the very 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.

Geographic Range [top]

Range Description: The range of this species extends from the Pacific coast to the Atlantic coast of North America (Conant and Collins 1991, Stebbins 2003). The northern limit of the more or less continuous portion of the range reaches Nova Scotia, southern Quebec, southern Ontario in Canada, Minnesota, southeastern South Dakota, eastern Nebraska, southeastern Colorado, and Arizona in the United States. The southern limit extends to San Luis Potosi (Mexico), the Gulf Coast of the United States, and southern Florida. The species also occurs disjunctly in western North America in eastern Washington, eastern Oregon, Idaho, Nevada, Utah, and Arizona, and it ranges from southern Washington through western Oregon and throughout much of California (except the Central Valley and deserts) into northwestern Baja California, including Islas Todos Santos and San Martin along the Pacific Coast (Grismer 2002). This species has been introduced on Grand Cayman Island (probably via ornamental plants from southern Florida), but it is unknown whether or not the species is established there (Schwartz and Henderson 1991).
Countries:
Native:
Canada; Mexico; United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This species is represented by thousands of occurrences or subpopulations. The total adult population size is unknown but undoubtedly exceeds 1,000,000. Local subpopulations may include several thousand individuals (e.g., Fitch 1975, 1982). Its extent of occurrence, area of occupancy, number of subpopulations, and population size are very large and probably relatively stable.
Population Trend: Stable

Habitat and Ecology [top]

Habitat and Ecology: This snake occurs in forests, woodlands, grassland, chaparral, and riparian corridors in arid regions (Stebbins 2003). Habitats are moist, at least seasonally. One or multiple individuals often are found near abandoned buildings and in junk piles in wooded areas. During daylight hours, this snake generally hides underground, in or under logs, or under rocks, stumps or other surface cover. Eggs are laid (often communally) underground or under logs or rocks.
Systems: Terrestrial

Threats [top]

Major Threat(s): No major threats to this species have been identified. Many local populations have been lost or reduced as a result of habitat destruction (Ernst and Ernst 2003), but these appear to amount to a small minority of the total distribution.

Conservation Actions [top]

Conservation Actions: Many occurrences of this species are in national parks or other well-protected areas.

Bibliography [top]

Blanchard, F.N. 1942. The ring-neck snakes, genus Diadophis. Bulletin of the Chicago Academy of Science 7: 1-144.

Cadle, J.E. 1984. Molecular systematics of neotropical xenodontine snakes, III: overview of xenodontine phylogeny and the history of New World snakes. Copeia 1984: 641-652.

Collins, J.T. 1991. Viewpoint: a new taxonomic arrangement for some North American amphibians and reptiles. SSAR Herpetological Review 22(2): 42-43.

Conant, R. and Collins, J.T. 1991. A Field Guide to Reptiles and Amphibians: Eastern and Central North America. Third Edition. Houghton Mifflin Company, Boston, Massachusetts.

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.

Ernst, C.H. and Ernst, E.M. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.

Fitch, H.S. 1975. A demographic study of the ringneck snake (Diadophis punctatus) in Kansas. Univ. Kansas Museum Natural History Miscellaneous Publication 62: 1-53.

Grismer, L.L. 2002. Amphibians and Reptiles of Baja California, Including its Pacific Islands and the Islands in the Sea of Cortés. University of California Press, Berkeley and Los Angeles, California.

IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: www.iucnredlist.org. (Accessed: 12th September 2007).

Pinou, T., Hass, C.A. and Maxson, L.R. 1995. Geographic variation of serum albumin in the monotypic snake genus Diadophis (Colubridae: Xenodontinae). Journal of Herpetology 29: 105-110.

Schwartz, A. and Henderson, R.W. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distributions and Natural History. University of Florida Press, Gainesville, Florida. xvi + 720 pp.

Stebbins, R.C. 1985. A Field Guide to Western Reptiles and Amphibians. Second Edition. Houghton Mifflin Company, Boston, Massachusetts.

Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. Third Edition. Houghton Mifflin Company, Boston, Massachusetts.

Welsh, H.H. 1988. An ecogeographic analysis of the herpetofauna of the Sierra San Pedro Martir region, Baja California with a contribution to the biogeography of the Baja California herpetofauna. Proceedings of the California Academy of Science, 4th series 46: 1-72.

Citation: Hammerson, G.A. & Frost, D.R. 2007. Diadophis punctatus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 24 April 2014.
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