Reptiles Guide

Rat snakes are a large, polyphyletic, group of snakes from the Colubrid subfamily Colubrinae. There is considerable variation between different types of rat snake but most are medium to large, rodent eating snakes.

Previously most were assigned to the genus Elaphe but many have been since renamed. The validity of some genera is debatable but for the purpose of this article a more liberal taxonomic stance will be taken. Rat snakes have traditionally been divided into two groups, New World and Old World species.

Examples of snakes found in the Elaphe include:

• Elaphe bairdi
  Elaphe bimaculata
  Elaphe carinata
  Elaphe climacophora
  Elaphe conspicillata
  Elaphe davidi
  Elaphe dione
  Elaphe emoryi
  Elaphe erythrura
  Elaphe flavirufa
  Elaphe flavolineata
  Elaphe gloydi
  Elaphe guttata
  Elaphe helena
  Elaphe hohenackeri
  Elaphe leonardi
  Elaphe lineata
  Elaphe longissima
  Elaphe maculata
  Elaphe mandarina
  Elaphe moellendorffi
  Elaphe obsoleta
  Elaphe perlacea
  Elaphe persica
  Elaphe porphyracea
  Elaphe prasina
  Elaphe quadrivirgata
  Elaphe quatuorlineata
  Elaphe radiata
  Elaphe rufodorsata
  Elaphe scalaris
  Elaphe schrenckii
  Elaphe situla
  Elaphe subradiata
  Elaphe taeniura
  Elaphe vulpina

New World Rat Snakes

New World rat snakes belong to the Colubrine tribe Lampropeltinae, and as such are closely related to Lampropeltis (milk snakes and king snakes), Pituophis (gopher snakes, pine snakes and bull snakes), Rhinocheilus (longnose snakes), Arizona (glossy snakes) and Stilosoma (short-tailed snakes). The entire Lampropeltinid group is descended from Old World rat snakes that crossed the Bering Land Bridge sometime within the last twenty to thirty million years.

The New World rat snakes consist of the genera Bogertophis (Trans Pecos and Baja rat snakes), Elaphe (Pantherophis) (Corn snakes, Fox snakes and American rat snakes), Pseudelaphe (Central American rat snake) and Senticola (Green rat snake).

Good Pictures at: http://www.kentuckysnakes.org/snake_details.cfm?snake_number=33&option=non-posionous

Old World Rat Snakes

The Genera Elaphe, Euprepiophis, Oreophis, Orthriophis, Rhinechis, and Zamenis constitute Old-World rat snakes.

Additional Note

It is worth noting that, though the polyphyletic nature of the genus is almost undisputed, many species are conservatively referred to as Elaphe sp. See, for instance, Black Rat Snake and Grey Rat Snake, subspecies of Pantherophis obsoleta.