Massasauga Rattlesnake

(Sistrurus catenatus)

Status: Endangered- Carolinian population, Threatened- Great Lakes / St. Lawrence population (COSEWIC 2012 & ESA 2014)

Table of Contents:

Species Identification
Diet
Habitat and Range
Biology and Behaviour
Similar Species
Threats/Reasons for Being Endangered
Conservation and Recovery Strategies
How You Can Help

Species Identification:

The Massasauga Rattlesnake is a short (50-70 cm), thick-bodied snake with a triangular head and a small rattle at the end of their tail that makes a buzzing sound. They are light gray or brown with uniformly spaced, solid dark brown coloured blotches located dorsally along the spine. These blotches are pinched in the middle and resemble a bowtie or butterfly silhouette. The Massasauga Rattlesnake is the only venomous snake in Ontario, but will only bite if harassed or threatened. They are also the only snake in Ontario with vertical, cat-like pupils.

Diet:

Massasauga Rattlesnakes are ambush predators, which means they prefer to sit and wait to come across their prey rather than hunting for them. Massasauga Rattlesnakes also have heat sensing pits that are located along the upper jaw in order to help them detect prey. Adult Massasaugas mainly rely on small mammals such as mice or voles for food, whereas juveniles have been known to prey on a wider variety of amphibians, other snake species, and invertebrates. They will use their venom to immobilize prey, and their colouring allows them to easily camouflage into their surroundings.

Map taken from Government of Canada: https://www.sararegistry.gc.ca/virtual_sara/files/cosewic/sr_Massasauga_1013_e.pdf

Habitat and Range:

Massasauga Rattlesnakes range from Ontario down through the United States and into northern Mexico. However, only the Eastern Massasauga subspecies is found in Ontario. The Ontario populations are separated into two distinct subpopulations- Great Lakes / St. Lawrence, and Carolinian. The Great Lakes / St. Lawrence population is limited to the Bruce Peninsula and eastern shore of Georgian Bay, which is within The Land Between. The Carolinian population only occurs within the Wainfleet Bog in Niagara, and the Ojibway Prairie complex near Windsor.

Massasauga rattlesnakes will live in various habitats depending on the climate and the time of year. The population that resides on the eastern shore of Georgian Bay tends to overwinter in mossy hummocks (peat) of lowland wetlands such as fens or bogs. Individuals on the Bruce Peninsula have been recorded using fissures in the ground that extend below the water table in forested areas, as well as in crayfish and animal burrows. Individuals in the Carolinian population are known to use already existing crayfish and mammal burrows. During the active season they will utilize a variety of habitats for foraging, gestation, and travelling. These tend to be semi-open or open habitats located along forest edge habitats. This allows for thermo-regulation, hiding, or escape from potential predators.

Biology and Behaviour:

The Massasauga Rattlesnake’s home range is quite small, usually around 1-1.5 km from their known hibernation sites. This is why it is important that they are not transported further than a few hundred meters from where they are found. Massasauga Rattlesnakes will mate in late spring and give birth in late summer. They will lay 2-19 eggs which will hatch immediately after birth. The young will remain in the area with their mother but there is no parental care needed. Generally females only give birth every 2-3 years. They typically emerge from hibernation in mid-late spring and return in mid-late October.

Despite being venomous, their small size and limited defensive abilities make them prey for a variety of raptors and mid-sized mammals. They are also generally docile and will not travel very far each day. Adults are most active at twilight and at night, while juveniles are more active during the day, as long as it is not too hot.

A juvenile Massasauga

Similar Species:

The Massasauga Rattlesnake is the only rattlesnake left in Ontario, but they can be confused with the Eastern Foxsnake, Eastern Hog-nosed Snake, Eastern Milksnake, and the Northern Watersnake. While the Eastern Foxsnake and Eastern Milksnake will vibrate their tails when threatened, all of these species lack a rattle, vertical pupils, and butterfly-shaped blotches.

Threats/ Reasons for being at Risk:

1. Habitat loss: Historically, and especially in Southern Ontario, wetlands were drained for agriculture. This was the initial main cause of decline for the Massasauga Rattlesnake, as wetlands are important habitats for hibernation. Despite their broad range of habitat types, they have all been impacted by agriculture, development, road construction, urbanization, and shoreline development.

2. Road mortality: Road mortality is a huge threat to all amphibians and reptiles, especially snake species. Massasauga Rattlesnakes are large, slow moving, and will freeze when they feel threatened or scared. They may also use roads for basking, and many drivers will either intentionally hit them, or not see them. There are very few areas in Ontario that do not have road networks every few kilometers, and road construction is only increasing, especially northward. Large highways with barriers are also detrimental to snakes, since it blocks them from crossing all the way and mortality is much more likely.

3. Persecution: All snake species are commonly persecuted by people due to fear. Most snakes in Ontario are generally harmless, but people fear their bite and their quick movements. Snakes are often found in people’s backyards and gardens, and while they are beneficial since they eat many backyard pests, they often frighten people. There is a great deal of misinformation when it comes to snake species, and most people would rather get rid of them than learn more about them. The Massasauga Rattlesnake is a large, venomous snake with a rattle, and people will often kill them immediately instead of educating themselves on the likelihood of being bitten or attacked.

4. Illegal collection: Snakes are often collected from the wild to be sold into the pet trade, or picked up by people who live nearby and given as a pet. Some snakes are also killed for their skin, or for medicinal purposes. Contrary to popular belief, poaching is common in Ontario and a huge threat to most reptile species. If you take a picture of a Species At Risk, remember not to post it on social media or give away any location data, as poachers will use this information.

Conservation and recovery strategies:

The Massasauga Rattlesnake and their habitat are protected in Ontario. Recovery strategies are based upon mitigating the current damage inflicted by road mortality, habitat loss, and persecution. Strategies that are listed include, but are not limited to, promoting alternate roadways that do not impede Massasauga habitat, installing eco-passages/culverts, outreach aimed at the public to dissuade from persecuting snakes, and protecting habitat in areas where Massasaugas are known to populate.

How can you help?

Report any Massasauga Rattlesnake sightings to The Land Between’s website or iNaturalist.
Encourage landowners to rehabilitate shoreline habitat and preserve any forest and wetland habitat on their land.
Educate your friends, family, and neighbours about Ontario snakes and the benefits and myths that are associated with them.
Landowners should look into safe chemical and pollutant use around their property.
Be aware of snakes on roads while driving and help a snake across the road in the direction they are travelling!
Support organizations dedicated to helping snakes and other wildlife.

Quick Facts:

Ontario holds roughly 10% of the global Massasauga population
Only two people in medical history have ever been killed by a Massasauga rattlesnake. The last one was over 50 years ago!
The majority of Massasauga rattlesnakes exhibit site fidelity. This means that they tend to stick around the same area for their entire life!

Additional Resources:

Ontario Nature Massasauga Rattlesnake page
Nature Conservancy Canada Massasauga Rattlesnake page
Information page from the Toronto Zoo

Sources:

COSEWIC. 2012. COSEWIC assessment and status report on the Massasauga Sistrurus catenatus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii + 84 pp. (www.registrelep-sararegistry.gc.ca/default_e.cfm).

Government of Ontario. 2021. Massasauga Rattlesnake. Retrieved from: https://www.ontario.ca/page/massasauga-rattlesnake

Government of Ontario. 2021. Massasauga Rattlesnake General Habitat Description. Retrieved from: https://www.ontario.ca/page/massasauga-rattlesnake-general-habitat-description

Government of Ontario. 2018. Massasauga (Carolinian and Great Lakes – St. Lawrence populations) government response statement. Retrieved from https://www.ontario.ca/page/massasauga-carolinian-and-great-lakes-st-lawrence-populations-government-response-statement

Government of Ontario. 2021. Recovery strategy for the Massasauga. Retrieved from: https://www.ontario.ca/page/recovery-strategy-massasauga

COSSARO. 2013. COSSARO Candidate Species at Risk Evaluation for Massasauga (Sistrurus catenatus) Great Lakes/St. Lawrence Population. Committee on the Status of Species at Risk in Ontario (COSSARO). Retrieved from: http://cossaroagency.ca/wp-content/uploads/2017/06/Final-COSSARO-Evaluation-Massasauga-GLSL-population-March-15_GFM_process....pdf