Pantherophis alleghaniensis

Utiger et al. (2002) examined mtDNA variation in New World and Old World "Elaphe" and determined that North American rat snakes currently included in the genus Elaphe form a monophyletic limeage 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. Based on mtDNA and nuclear DNA data, Burbrink and Lawson (2007) determined that New World Elaphe are not closely related to Old World Elaphe. While further splitting of Pantherophis has been proposed (Collins and Taggart 2008), the use of Pantherophis has helped stabilize the classification of New World ratsnakes. Thus, Crother (2017) refrain from further division of the genus.

Large range in eastern North America; large area of occupancy; presumed large population size; trend uncertain: better information is needed on population impact of snake fungal disease. Better information is needed on distribution relative to Pantherophis spiloides.

This species occurs in the eastern United States, from New England to southern Florida, east of the Appalachian Mountains, east of the Apalachicola River in Florida, and east of the Chattahoochee River in Georgia; western edge of range is poorly defined, and a large area of taxonomic uncertainty potentially involving hybridization with P. spiloides extends from eastern New York and New England to northern Georgia (Burbrink 2001). A ratsnake species has been introduced in the Bahamas (Abacos; Buckner and Franz, 1994, Herpetol. Rev. 25:166), but whether it represents this species or another is uncertain from information presented in the published record.

The number of distinct occurrences has not been determined using consistent criteria, but this species is represented by a very large number of collection sites and locations (as defined by IUCN).

Intensive agricultural development and urbanization have caused localized declines, and collectors probably have depleted some easily accessible populations, but in most areas this snake is not threatened by these factors. This species is vulnerable to snake fungal disease; the scope, severity, and population impact of this disease on P. alleghaniensis are uncertain but potentially significant.