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Squamata   suborder Serpentes     
Elaphe guttata-- Great Plains Ratsnake

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Monroe County, IL; photo by Mike Redmer distribution map

Purple shade indicates vouchered specimens. Light blue (cyan) shade indicates photographic records. Yellow shade indicates verified sighting. Slanted hatch indicates pre-1980 records only

NOTE: Not all specimens upon which these maps are based have been verified.


Key Characters: Spear-shaped pattern on top of head; body scales keeled; anal plate divided.

Similar Species: Prairie kingsnake, milk snake, fox snake, rat snake.

Description: Moderately large (up to 120 cm TL), blotched snake with gray or light brown back sporting 25 to 50 black-bordered, nearly square, dark brown or red-brown blotches. Tail with 8-20 dark spots or bands. Belly checkered black and white.

Habitat: Rocky, wooded hillsides, hill prairies, bluffs, and adjacent brushy fields.

Natural History: This nocturnal snake mates in April or May and lays 3-30 eggs a few weeks later. The young, 30-35 cm TL, hatch in August. Diet includes mammals, birds, and bird eggs. Medium-sized mammals and raptors are the main predators.

Status: Threatened in Illinois. Found only along the Mississippi River bluffs from Jersey to Randolph counties, where its main threat is highway traffic.