About Pantherophis alleghaniensis (Holbrook, 1836)
Pantherophis alleghaniensis, commonly called the gray ratsnake or central ratsnake, is a medium to large snake species. Adult gray ratsnakes typically reach a total length (including the tail) of 99–183 cm (3.25–6.00 ft), with a recorded maximum length of 213.9 cm (7.02 ft).
Unlike other species in the Pantherophis genus, where conspicuous juvenile patterning fades as individuals reach adulthood, gray ratsnakes in the southern portion of their range do not experience drastic age-related changes to their color or markings. Instead, these southern individuals retain the juvenile patterning: dark elongated dorsal blotches separated by four or more pale gray body scales, a light gray crown with dark striping that forms an anterior-facing spearpoint, and a solid band that covers the eyes and extends backward to the posterior upper labial scales. In the northern part of the species’ range, adult gray ratsnakes are solid black, similar to the closely related yellow ratsnake (P. quadrivittatus) and western ratsnake (P. obsoletus).
The underside of the gray ratsnake is usually off-white or pale gray with darker irregular blotches, and has a double row of black spots behind the divided anal plate of the vent. Dorsal scale rows around the midbody are usually weakly keeled.
This species is native to North America. It is commonly found in forests across the eastern and central United States, in the area west of the Appalachian Mountains and east of the Mississippi River. Its distribution runs relatively continuously across most of the eastern half of the United States, extending from southwestern New England south to the Gulf of Mexico, west to the Mississippi River, and north from northern Louisiana to southwestern Wisconsin, including along the Piedmont through Kentucky. In Canada, the species occurs in two separate disjunct regions of southern Ontario: the Carolinian forest region along the north shore of Lake Erie in the southwest, and the Great Lakes/St. Lawrence region in the southeast.
Pantherophis alleghaniensis readily hybridizes with P. quadrivittatus in the east and P. obsoletus in the west. This hybridization creates large zones of taxonomic uncertainty, where species-level identification of individuals can be difficult.
The gray ratsnake is an agile climber, and it occupies habitats ranging from the ground up to tree tops. It can be found in many types of hardwood forest and cypress stands, along tree-lined streams and fields, and even around barns and sheds in areas close to people. It climbs trees to search for prey including the contents of bird nests and squirrel dreys. Within its distribution range, almost any environment that has abundant rodent populations and vertical escape options is a suitable habitat for this species.
Breeding for Pantherophis alleghaniensis occurs from April to July. Females reach sexual maturity at 7 to 9 years of age. They lay a clutch of 5 to 27 eggs around mid-summer, and hatchlings, which measure 25–30 cm (9.8–11.8 in) long, usually emerge in September.
