Eastern Copperhead

The eastern copperhead (Agkistrodon contortrix), also known simply as the copperhead, is a widespread species of venomous snake, a pit viper, endemic to eastern United States of America; it is a member of the subfamily Crotalinae in the family Viperidae.

The eastern copperhead has distinctive, dark brown, hourglass-shaped markings, overlaid on a light reddish brown or brown/gray background. The body type is heavy, rather than slender. Neonates are born with green or yellow tail tips, which progress to a darker brown or black within one year. Adults grow to a typical length (including tail) of 50–95 cm (20–37 in).

In most of the United States of America, the eastern copperhead favors deciduous forest and mixed woodlands. It may occupy rock outcroppings and ledges, but is also found in low-lying, swampy regions. During the winter, it hibernates in dens or limestone crevices, often together with timber rattlesnakes and black rat snakes. The eastern copperhead is known to feed on a wide variety of prey, including invertebrates (primarily arthropods) and vertebrates. Like most pit vipers, the eastern copperhead is generally an ambush predator; it takes up a promising position and waits for suitable prey to arrive.

As a common species within its range, it may be encountered by humans. Unlike other viperids, it often "freezes" instead of slithering away and fleeing, due to its habit of relying on excellent camouflage. Bites occur due to people unknowingly stepping on or near them. Copperhead bites account for half of the treated snake bites in the United States.

Five subspecies have been recognized in the past, but recent genetic analysis has yielded new species information.

Etymology

Its generic name is derived from the Greek words ankistron "hook, fishhook" and odon, variant of odous "tooth". The trivial name, or specific epithet, comes from the Latin contortus (twisted, intricate, complex), which is usually interpreted to reference the distorted pattern of darker bands across the snake's back, which are broad at the lateral base, but "pinched" into narrow hourglass shapes in the middle at the vertebral area.

Description

Adults grow to a typical length (including tail) of 50–95 cm (20–37 in). Some may exceed 1 m (3 ft 3 in), although that is exceptional for this species. Males do not typically exceed 74 to 76 cm (29 to 30 in) and weigh from 101.5 to 343 g (3+9⁄16 to 12+1⁄8 oz), with a mean of roughly 197.4 g (6+15⁄16 oz). Females do not typically exceed 60 to 66 cm (23+1⁄2 to 26 in), and have a mean body mass of 119.8 g (4+7⁄32 oz). The maximum length reported for this species is 134.6 cm (53 in) for A. c. mokasen (Ditmars, 1931). Brimley (1944) mentions a specimen of A. c. mokasen from Chapel Hill, North Carolina, that was "four feet, six inches" (137.2 cm), but this may have been an approximation. The maximum length for A. c. contortrix is 132.1 cm (52 in) (Conant, 1958).