Pituophis catenifer is a species of non-venomous colubrid snake endemic to North America. Nine subspecies are currently recognized, including the nominotypical subspecies, P. c. catenifer, described here. This snake is often mistaken for the prairie rattlesnake (Crotalus viridus), but can be easily distinguished from a rattlesnake by the lack of a tail rattle, no black-and-white banding on its tail, and by the shape of its head, which is narrower than a rattlesnake's. Additionally, rattlesnakes (and indeed most vipers) possess a large venom gland located behind each eye, giving their heads a much rounder, more angular shape, as opposed to the more cylindrical, slender head shape of a gopher snake or other colubrid.

Etymology

The specific name, catenifer, is Latin for "chain-bearing", referring to the dorsal color pattern.

Description

Adult gopher snakes average between 36-84 in (91–213 cm) in length, or up to 6 or 7 feet, when fully mature. Dorsally, gopher snakes are yellowish or a light, sandy brown, with a series of large, dark brown or black markings and smaller, darker spots along the sides. Ventrally, they are a lighter yellowish, either uniformly or with brown markings. They also come in several morphs, depending on the subspecies.

Behavior

The gopher snake has a unique defensive mechanism, in which it puffs up its body and curls itself into the classic strike pose of a rattlesnake. However, rather than delivering an open-mouthed strike, the gopher snake often strikes with a closed mouth, using its blunt nose to warn off possible predators. Additionally, gopher snakes vibrate their tails in a manner similar to rattlesnakes. One paper found that gopher snakes on islands lacking rattlesnakes vibrate their tails for shorter amounts of time than gopher snakes in mainland California, which is home to numerous rattlesnake species. This suggests that gopher snake tail vibration may in fact be rattlesnake mimicry since the behavior appears to be breaking down in areas without rattlesnakes, perhaps because predators on these islands have no reason to evolve to avoid tail-vibrating snakes (rattlesnakes are venomous, gopher snakes are not).

Life expectancy

Wild gopher snakes typically live 12 to 15 years, but the oldest captive recorded lived over 33 years.

Common names

Common names for this species, or its several subspecies, are: Pacific gopher snake, Henry snake, coast gopher snake, bullsnake, Churchill's bullsnake, Oregon bullsnake, Pacific pine snake, western bullsnake, western gopher snake, Sonoran gopher snake, western pine snake, great basin gopher snake, blow snake, and yellow gopher snake.

Subspecies

As of 2022, there is nearly-unanimous agreement on the recognition of six subspecies, occurring from southern Canada, the continental United States, and Mexico. However, there is not full agreement among taxonomists on the status of populations from Baja California and some offshore islands; the Cape gophersnake (Pituophis catenifer vertebralis) and central Baja Californian gophersnake (P. catenifer bimaris) are recognized, by some sources, as a single species (with no subspecies vertebralis). Some other sources, alternatively, consider it a species with two subspecies: P. v. vertebralis and P. v. bimaris. Other subspecies, including the Coronado Island gophersnake (P. catenifer coronalis) and San Martin Island gophersnake (P. catenifer fulginatus) are of questionable validity.

Gallery