|Scientific Name:||Pantherophis guttatus|
|Species Authority:||(Linnaeus, 1766)|
Coluber guttatus Linnaeus, 1766
|Taxonomic Notes:||Burbrink (2001) used cytochrome b sequences to examine phylogenetic relationships among E. guttata populations (one specimen from each of 53 locations throughout most of the range). He found no support for recognition of the nominal subspecies intermontanus and meahllmorum as distinct taxa; these appear to be junior synonyms of E. guttata emoryi. Burbrink identified three partitions of E. guttata: an eastern partition (east of the Mississippi River) corresponding to E. guttata guttata, a western partition corresponding to E. guttata emoryi (including E. g. intermontanus and E. g. meahllmorum), and a central partition in western Louisiana and eastern Texas. The central partition, in pine and pine-hardwood habitat west of the Mississippi River, clustered closer to the eastern partition than to the western partition. Burbrink recognized the three partitions as species using evolutionary species criteria: (1) Elaphe guttata (Red Corn Snake) (eastern partition ), (2) Elaphe emoryi (Great Plains Rat Snake) (western partition), and (3) Elaphe slowinskii (Slowinski's Corn Snake) (central partition). One specimen (Hidalgo County, Texas) of the central partition (based on cytochrome b characteristics) was located outside the presumed geographic area and habitat identified for other members of that partition. Crother et al. (2003) adopted these changes. Ernst and Ernst (2003) recognized E. emoryi and E. guttata as distinct species, but their manuscript evidently was completed before Burbrink's paper was published; they did not comment on E. slowinskii.
Utiger et al. (2002) examined mtDNA variation in New World and Old World "Elaphe" and determined that North American rat snakes included in the genus Elaphe form a monophyletic lineage that is distinct from Old World snakes that also have been regarded as Elaphe. They resurrected the genus Pantherophis for the rat snakes north of Mexico, including the following species: Pantherophis obsoletus (and P. alleghaniensis and P. spiloides, if one recognizes those taxa as species), P. guttatus, P. emoryi, P. vulpinus, P. gloydi, and P. bairdi. Crother et al. (2003) noted this proposal but did not adopt it, pending further review. Burbrink and Lawson (2007) agreed with Utiger et al. (2002) that these species do not belong in Elaphe, but suggested that the genus Pantherophis might belong in Pituophis. We retain this species in Pantherophis, following Utiger et al. (2002) pending further information on the relationships of these taxa.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer/s:||Cox, N., Chanson, J.S. & Stuart, S.N. (Global Reptile Assessment Coordinating Team)|
Listed as Least Concern in view of the large extent of occurrence, area of occupancy, number of subpopulations, and population size, and because the species probably is not declining fast enough to warrant listing in any of the threatened categories.
|Range Description:||This species is endemic to eastern and southeastern United States. Its range extends from southern New Jersey, Maryland, and Kentucky southward to southeastern Louisiana, southern Mississippi, southern Alabama, and southern Florida (Conant and Collins 1991, Burbrink 2002). Introduced on Grand Cayman Island and Grand Bahama Island (Buckner and Franz, 1994, Herpetological Review 25: 166) and elsewhere in the Caribbean region (e.g., may be established on St. Thomas, U.S. Virgin Islands; Perry et al. 2003).|
Native:Mexico; United States
Introduced:Bahamas; Cayman Islands; Virgin Islands, U.S.
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is represented by a large number of occurrences (subpopulations). Adult population size is unknown but presumably exceeds 10,000 and probably exceeds 100,000. Extent of occurrence, area of occupancy, number of subpopulations, and population size probably are relatively stable or declining at a rate of less than 10% over 10 years or three generations.|
|Habitat and Ecology:||This species is mostly semi-fossorial, inhabiting in a wide variety of environments, from dry to humid, including pine forest, grass flatwoods, grasslands, open rock areas, and tropical hammocks.|
|Major Threat(s):||No major threats are known. Habitat destruction is a local threat in some areas, but this species tolerates a fair amount of low intensity habitat alteration.|
|Conservation Actions:||Many occurrences are in protected areas.|
Bartlett, R D. and Bartlett, P.P. 1999. A Field Guide to Texas Reptiles and Amphibians. Gulf Publishing Company, Houston, Texas. xviii + 331 pp.
Burbrink, F.T. 2001. Systematics of the eastern ratsnake complex (Elaphe obsoleta). Herpetological Monographs 15: 1-53.
Burbrink, F.T. 2002. Phylogeographic analysis of the corn snake (Elaphe guttata) complex as inferred from maximum likelihood and Bayesian analyses. Molecular Phylogenetics and Evolution 25(3): 465-476.
Burbrink, F.T. and Lawson, R. 2007. How and when did Old World rat snakes disperse into the New World? Molecular Phylogenetics and Evolution 43: 173-189.
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 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.
Dundee, H.A. and Rossman, D.A. 1989. The Amphibians and Reptiles of Louisiana. Louisiana State University Press, Baton Rouge, Louisiana.
Ernst, C.H. and Ernst, E.M. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.
IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: www.iucnredlist.org. (Accessed: 12th September 2007).
Mount, R.H. 1975. The Reptiles and Amphibians of Alabama. Auburn University Agricultural Experiment Station, Auburn, Alabama. vii + 347 pp.
Schulz, K.D. 1996. A monograph of the Colubrid snakes of the genus Elaphe Fitzinger. Koeltz Scientific Books, Germany.
Tennant, A. 1997. A Field Guide to Snakes of Florida. Gulf Publishing Company, Houston, Texas. xiii + 257 pp.
Utiger, U., Helfenberger, N., Schmidt, B., Ruf, M. and Ziswiler, V. 2002. Molecular systematics and phylogeny of Old and New World ratsnakes, Elaphe auct., and related genera (Reptilia, Squamata, Colubridae). Russian Journal of Herpetology 9(2): 105-124.
|Citation:||Hammerson, G.A. 2007. Pantherophis guttatus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 16 April 2014.|
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