Species at Risk

Massasauga Rattlesnake


Sistrurus catenatus catenatus

Species at Risk - Who Knew?

Two people are known to have died from a rattlesnake bite in Ontario. Neither victim received medical treatment.

Why is the massasauga in danger?

Monitoring studies since the early 1990s show that the massasauga population is declining throughout its range. The greatest threat to this snake is the loss and fragmentation of its habitat. Timber harvesting, quarry digging, housing and cottage developments and draining wetlands for agriculture have all taken their toll. Road construction has not only reduced available habitat, but has also fragmented the reptile's range. Roads also mean more vehicle traffic and more road kills, especially in spring and fall when the snakes migrate between their summer and winter habitats.

Close-up of a massasauga's rattle.
Its hollow rattle is made of segmented scales.
© Parks Canada / D.A. Wilkes / 06.64.10.10 (02), 1989

Another significant threat in some areas is the deliberate killing of the snake by humans. People's reactions to the snake are often ruled by fear and prejudice, so encounters between humans and the reptile frequently end fatally-for the snake. While the snake has natural predators, including great horned owls and red-tailed hawks, fishers, red foxes, coyotes and raccoons, it is persecution by humans that has been a major contributor to the decline of the species throughout its range.

Poaching is also a factor in the reptile's disappearance, but scientists don't know how widespread it is, nor how many snakes are caught for sale each year.

The total Ontario population of massasaugas is estimated to be between 18,000 and 32,000 snakes, with fewer than 100 snakes in each of the two southwestern populations. Isolated populations are particularly susceptible to extirpation (extinction within Canada ) as a result of chance incidents such as disease. Even the loss of a single breeding adult can be devastating for a small, isolated population such as that in the Wainfleet Bog or the Ojibway Prairie Complex.