Species At Risk


(Sistrurus catenatus)


Massasauga occurrences map


The Massasauga is a stout-bodied rattlesnake, usually about 50 to 70 centimetres long. It is Ontario’s only venomous snake, though it will only bite in self-defence if it is threatened or harassed. It has a triangular head and a tail that ends in a small rattle that creates a buzzing sound when the tail shakes. The body is grey to dark brown with darker brown “butterfly” or “saddle-shaped” blotches down the back, with alternating blotches along the sides. The Massasauga is the only Ontario snake with a vertical (cat-like) pupil.


In Canada, the Massasauga is found only in Ontario, primarily along the eastern side of Georgian Bay and on the Bruce Peninsula. Two small populations are also found in the Wainfleet Bog on the northeast shore of Lake Erie and near Windsor. The Massasauga was once more widespread in southwestern Ontario, especially along the shores of the Great Lakes.


Massasaugas live in different types of habitats throughout Ontario, including tall grass prairie, bogs, marshes, shorelines, forests and alvars. Within all of these habitats, Massasaugas require open areas to warm themselves in the sun. Pregnant females are most often found in open, dry habitats such as rock barrens or forest clearings where they can more easily maintain the body temperature required for the development of their offspring. Non-pregnant females and males forage and mate in lowland habitats such as grasslands, wetlands, bogs and the shorelines of lakes and rivers. Massasaugas hibernate underground in crevices in bedrock, sphagnum swamps, tree root cavities and animal burrows where they can get below the frost line but stay above the water table.


The most significant threats to the Massasauga are persecution by humans, mortality on roads, and loss of habitats. These threats led to the disappearance of this species from most of its historic range in southwestern Ontario.


The Massasauga is protected under Ontario’s Endangered Species Act, the Ontario Fish and Wildlife Conservation Act and the federal Species at Risk Act.

What You Can Do to Help the Massasauga

  • The Ministry of Natural Resources tracks species at risk such as the Massasauga. The Ontario Reptile and Amphibian Atlas collects observations of all Ontario reptiles and amphibians. Submit your observations to either of these databases at nhic.mnr.gov.on.ca/species/species_report.cfm and www.ontarionature.org/atlas. Photographs are important to help confirm the identification of species and are always helpful.
  • Appreciate snakes and don’t harm them. Sadly, the deliberate killing of snakes by humans is a significant threat to the Massasauga and other Ontario snakes. Human persecution led to the eradication of the Timber Rattlesnake from Ontario.
  • If you come across a snake, please don’t try to capture it, handle it or kill it. Snakes can be delicate and improper handling can cause serious injury. Also, certain species are protected under legislation, which makes it illegal to harass, harm or kill them. Be respectful and observe from a distance.
  • Take a few easy steps to protect yourself while hiking in known Massasauga habitat (e.g., the Bruce Peninsula). Wear leather hiking boots and loose-fitting long pants. When in Massasauga habitat, always watch where you are walking and never reach into areas that you cannot see.
  • If you are bitten by a Massasauga, remain calm and call emergency services. Never try to catch or kill the snake. It is unnecessary, dangerous and illegal.
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Watch for snakes that may be crossing roads between May and October. Road mortality is a serious threat to snakes because they are slow moving, hard to see on the road and are sometimes intentionally run over.
  • Private land owners have an important role to play in species at risk recovery.If you find a Massasauga on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • Visit the Ontario reptile and Amphibian Atlas ( www.ontarionature.org/atlas) or Toronto Zoo Adopt-a-Pond website ( www.torontozoo.com/Adoptapond) to learn more about Ontario’s rare snakes, their habitat and related conservation initiatives.

Did you know?

No one has died from a Massasauga bite in Ontario in more than 50 years, and only two deaths resulting from a Massasauga bite have ever been reported in the province.

Did you know?

A snake’s rattle is made up of loosely attached pieces of keratin (the same material that our fingernails are made from) that knock against each other and create a rattle or buzzing sound when the tail is shaken.

Did you know?

Although the Massasauga is Ontario’s only rattlesnake, it’s not the only one that vibrates its tail. The Eastern Foxsnake and Eastern Milksnake are non-venomous snakes that mimic the rattlesnake by quickly vibrating the tip of their tails. If the tail comes into contact with leaf litter as it’s vibrating, it can make a buzzing sound.

Did you know?

The Massasauga is very shy and prefers to hide or retreat from enemies rather than bite them. If threatened, it will shake its tail as a warning and strike only as a last resort to protect itself if it can not escape.

Did you know?

Sometimes the Massasauga will share its hibernation sites with other hibernating snakes, amphibians and even crayfish!

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.