Timber rattlesnake (Crotalus horridus)

Identification and characteristics

This species has a stout body, prominent heat-sensing pits between the eyes and nostrils, and a segmented rattle produced by modified scales. Typical identifying features include a heavy build, a pronounced head distinct from the neck, vertical pupils, and patterned dorsal blotches. Juveniles may lack a full rattle and often show brighter contrast in their markings.

Distribution, habitat and ecology

Timber rattlesnakes inhabit a range of forested and rugged landscapes in eastern North America, from hardwood forests and rocky ridges to river valleys and mixed woodlands. They use den sites for communal hibernation in colder parts of their range and disperse seasonally to feed and reproduce. Diet consists mainly of small mammals, birds, and occasionally amphibians; they are ambush predators that rely on camouflage and a strike-and-release hunting strategy.

Behavior and human interactions

These snakes are generally secretive and avoid people when possible, giving warning by vibrating their tails when threatened. Bites are relatively uncommon but can be serious because the venom is hemotoxic and can cause local tissue damage, swelling, and systemic effects if untreated. Medical attention and antivenom are important after a confirmed bite; routine killing of snakes is discouraged in many areas because of legal protections and ecological roles.

Conservation and notable facts

Populations have declined in parts of the range due to habitat loss, persecution, road mortality, and collection. Conservation status varies regionally; some states list the species as threatened or endangered and protect denning and foraging habitats. The timber rattlesnake plays a role in controlling rodent populations and is part of local cultural histories. For range information and species accounts see regional guides and conservation resources.

Quick identification checklist

• Stout, heavy-bodied viper with triangular head
• Distinctive segmented rattle at tail tip
• Vertical pupils and heat-sensing facial pits
• Banded or blotched pattern, color variable by locality