Midland Rat Snake

(Elaphe spilodes)

Color Photographs: U.S. National Parks Service

Midland Rat Snake (Elaphe spilodes)

Identification: Snake 34 to 100 inches in length. Species with two color forms:

Black form: Color on back and sides black, but with some white showing around the margins of the scales. Chin white. Underside white to gray.

Blotched Form: Brown to violet-brown with irregular, darker blotches along the top of the body and with a row a irregular blotches along the side.

Scales weakly keeled and anal plate divided. Scales on the belly with their ends sharply turned upward.

Geographical Variation: None.

Range (See map on left): The eastern boundary of this species is defined in the literature as approximately a straight line from the Apalachicola River in Florida (W85 degrees longitude) drawn straight upward to about central Michigan. The western boundary is the Mississippi River. The northern boundaries are in central Michigan, southern Illinois and western Wisconsin.

Habitat: The Midland Rat Snake is found primarily in deciduous forest, but also occupies farmland, abandoned buildings, old fields, and swamps.

Food: Small mammals, birds, and bird eggs.

Behavior: This species is diurnal during the spring and fall, but nocturnal during the hot days of the summer. The Midland Rat Snake is an excellent and prodiguous climber and is commonly found in trees and shrubs. It kills its prey by constriction.

Reproduction: No exact data because of confusion with the Western Rat Snake and the Eastern Rat Snake. Clutch consisting of 5 to 30 eggs. The snake mates in both the spring and in the fall. The eggs are typically laid under logs, rocks, or in leaf litter.

Note: The taxonomy for this segment of Nearctica follows, Collins and Taggart, 2007, Center for North American Herpetology, http://www.cnah.org./. Some herpetologists do not accept the division of the species formerly known at the Rat Snake into the three species Elaphe obsoleta, Elaphe spilodes, and Elaphe appalachiensis because of the arbitrary division of the distribution into three non-overlaping ranges, the lack of field characters to separate the three species, and the absence of any apparent evidence that the three species are reproductively isolated. For those who recognize only a single species, the correct name is Elaphe obsoleta.

Midland Rat Snake (Elaphe spilodes)

The three species, Elaphe obsoleta (Western Rat Snake), Elaphe spilodes (Midland Rat Snake), and Elaphe appalachiensis (Eastern Rat Snake) cannot be separated by field characters or appearance. The three species, as currently defined, are separated in the field by distribution.

Eastern Racer (Coluber constrictor)

Pine Snake (Pituophis melanoleucus)