|
Canadian Herpetological Society Société d'Herpétologie du Canada |
|---|
Timber Rattlesnake
Crotalus horridus
Family: Viperidae
COSEWIC status:- Extirpated
- Extirpated
- Least Concern
Description
The Timber Rattlesnake is heavy-bodied and can grow to almost 2 m in length. It has an unmarked triangular head, vertical pupils, heat-sensing pits and usually a rattle at the end of its tail. Generally, this snake is yellow, brown or grey with dark chevron or v-shaped cross bands and a solid-coloured darker tail. However, some individuals are all black.
Similar Species
The only other rattlesnake in eastern Canada is the Massasauga, which has dark bars on the top of the head and butterfly-shaped blotches on the back. Adult Massasaugas are much smaller, reaching a maximum length of only 1 m, with most adults typically 60–75 cm in length.
Distribution
Click for larger image
No longer occurs in Canada. The last confirmed report of a Timber Rattlesnake in Canada was from Ontario in 1941. Historically, it was found in southern Ontario, in the Niagara area and on Pelee Island. There is one report from the 1880s on Fitzwilliam Island in Lake Huron. In the United States, this species ranges from New Hampshire west to Minnesota, and south to Texas and Florida. Isolated populations occur in Massachusetts, North Carolina and Ohio.
Habitat
Timber Rattlesnakes inhabit upland forests with associated clearings and rocky areas. This snake hibernates communally in talus slopes and rocky crevices, usually those that face south.
Biology
Timber Rattlesnakes breed primarily in the fall, and females give birth to an average of 10 live young in the fall of the following year. At birth, the young are 19–38 cm in length. Females reach maturity after 7–13 years when they are usually larger than 1 m in length, and they only reproduce only once every two to six years. The Timber Rattlesnake is a long-lived species, and some individuals are thought to live for over 30 years. Individuals return to the same hibernation site year after year. In the summer, these snakes move up to 7 km away from their hibernation site to search for food and mates. Like all rattlesnakes, the Timber Rattlesnake is a pit viper; two heat-sensitive pits between its eyes and nostrils allow it to see thermal images of its environment. This ability, along with its venom and camouflage, make the Timber Rattlesnake a very effective ambush predator of small mammals, its primary prey.
Threats
Human persecution and habitat loss are responsible for the extirpation of this species in Canada. Within its range in the U.S., road mortality is also a threat. Snake Fungal Disease is a new emerging threat to snakes in North America, especially rattlesnakes, which has caused significant decline in some Timber Rattlesnake populations.