Timber Rattlesnake
(Crotalus horridus)

Photos by Mike Marchand

Timber rattlesnakes are large, heavy-bodied snakes. In New Hampshire, most rattlesnakes (only one known population remaining!!!) are black with little or no pattern. The timber rattlesnake is the only snake in NH with vertical pupils. Rock crevices are used for shelter.

The timber rattlesnake is the only snake in New Hampshire that actually has a rattle. Other snakes may shake their tails that sound like a rattle! Rattles are used to warn potential intruders of the snakes’ presence. Timber rattlesnakes are NH’s only venomous snake but also are very docile and are unlikely to strike unless provoked or stepped on. Timber rattlesnakes are an endangered species in New Hampshire and are protected by state law.

A young dark timber rattlesnake with brown blotches. Timber rattlesnakes hibernate 6 months a year and have limited time to soak up the sun’s rays, which is needed to feed, grow, and reproduce.

This rattlesnake, born in the previous fall, is vulnerable to a number of predators including hawks, coyotes, turkeys…even other snakes.

Timber rattlesnakes need rocky ledges where they retreat below the winter’s frost line.

NH Conservation Status: State Endangered; Wildlife Action Plan Species in Greatest Need of Conservation (Click here to download the Reptiles and Amphibians section of the NH Wildlife Action Plan. (PDF, 1.5 MB.) Timber rattlesnake is on page 68.)

State Rank Status: Critically imperiled

Distribution: Historically ranged from Massachusetts border up to the White Mountains. Currently there is only one known population in NH.

Description: A large, thick black snake measuring 36-60 inches. Brown cross-bands arranged across the surface may be difficult to see. Has a large triangular head and keeled scales giving them a rough appearance. At the end of the tail there is a large, blunt rattle.

Commonly Confused Species: Milk snake, northern water snake, black racer; garter snake

Habitat: Rocky, south-facing hillsides in wooded areas that are exposed to an abundance of sunlight. Rock ledges and outcroppings on hilltops are used for basking. Deep rock crevices are used as den sites for hibernation. During summer their habitat expands to brushy, forested areas where they often bask in sunspots. Males may travel several miles from den sites during summer and return in the fall.

Life History: Timber rattlesnakes give birth to live young in the fall before returning to the den to hibernate from November until May. They den communally and will use the same den site for generations.

Conservation Threats: Habitat loss and destruction, gravel mining, mortality on roadways, illegal collection or killing of snakes by humans.