Timber Rattlesnake
Crotalus horridus • Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Crotalus, Species: horridus
Eastern United States, from southern New Hampshire to northern Florida, stretching west to eastern Texas, Oklahoma, and Minnesota.
Look up Timber Rattlesnake in the Snake Encyclopedia →Venomous Status
Venomous; solenoglyphous (large, retractable front fangs).
Danger Level
Extremely Dangerous; high risk due to large size, high venom yield, and potent toxins. Potential for fatalities without medical treatment.
Family
Order: Squamata, Suborder: Serpentes, Family: Viperidae, Subfamily: Crotalinae, Genus: Crotalus, Species: horridus
Conservation
Least Concern globally, but endangered or protected in many northeastern U.S. states due to habitat loss and persecution.
Physical Description
Heavy-bodied pit viper with distinct dark brown or black crossbands or chevrons on a gray, tan, or yellowish background. The tail is usually solid black, terminating in a keratinous rattle.
Size & Dimensions
Typically 91–152 cm (36–60 in) in length. Maximum recorded is about 189 cm (74 in). Adult specimen shown.
Habitat
Deciduous and mixed forests with rocky outcrops; prefers rugged terrain, upland woods, and floodplains. Elevation ranges from sea level to over 1,800 meters in the Appalachian Mountains.
Behavior & Temperament
Generally shy and reclusive, preferring to remain coiled and hidden. If threatened, it will rattle its tail as a warning; it is not aggressive but will defend itself vigorously if stepped on or provoked.
Diet & Feeding
Primarily small mammals (squirrels, mice, chipmunks), birds, and occasionally other snakes. Uses ambush strategy (sit-and-wait) near fallen logs or trails using infrared pit organs.
Reproduction
Viviparous (gives birth to live young). Late summer/autumn births with litter sizes typically between 5 and 14 young. Low reproductive rate (females breed every 3–6 years).
Venom Profile
Variable; primarily hemotoxic and cytotoxic causing localized tissue damage and coagulopathy, but some populations exhibit neurotoxic (Type B) components.
Look-alikes
Eastern Copperhead (lacks rattle, hourglass markings), Black Racer (slender, no pattern when adult), and various Garter or Watersnakes (lack pit viper head shape).
Conservation Status
Least Concern globally, but endangered or protected in many northeastern U.S. states due to habitat loss and persecution.
Cultural Significance
Historical symbol of the American colonies (Gadsden flag: 'Don't Tread on Me'). Key apex predator in forest ecosystems, controlling rodent populations.
Notable Features
Highly developed heat-sensing loreal pits located between the eye and nostril, and a unique tail rattle and specialized rattle-shaker muscles that can vibrate at extremely high speeds.