Fast Facts: Prairie rattlesnake

Species name: Crotalus viridis viridis
Average length: 89 cm to 114 cm
Life expectancy: 16-20 years

Did you know?

The prairie rattlesnake is the only venomous snake in the Canadian prairies.


The prairie rattlesnake is the only venomous snake in the Canadian prairies.

It is best known for the unique rings on the end of its tail that knock together and make a rattling sound. The flat, triangular-shaped head hides a pair of the retractable fangs. The body ranges from greenish gray to greenish brown in colour, with dark blotches on the back and a cream-coloured underbelly.

A rattle is added to the string each time the rattlesnake sheds its skin, which happens up to five times in its first summer and around one to two times a year after that. Males tend to have more rings than females.


Because it is cold blooded, the prairie rattlesnake’s body temperature is affected by its surroundings.

During the winter it hibernates in caves and in the burrows of other animals. In the cool spring and fall weather the rattlesnake hunts in the daytime, while the hotter summer days force it to hunt at night.

The prairie rattlesnake is not aggressive and will usually flee if given the chance. But as a predator it has unique assets. It uses its tongue as part of its smell- and heat-sensing membranes, allowing it to detect something from as far as 30 metres away.

The prairie rattlesnake hunts by striking rapidly at its prey and immobilizing them with the poisonous venom in its fangs. Its normal striking distance is two-thirds of the snake’s body length (60 to 76 centimetres, on average). The rattlesnake preys upon small mammals, amphibians, reptiles and ground nesting birds.


The prairie rattlesnake can be found in southwestern Saskatchewan and southeastern Alberta. In the United States, its range extends from Idaho and Montana to western Iowa to northern Mexico.

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