Species At Risk

Butler’s Gartersnake

(Thamnophis butleri)


Butler’s Gartersnake
Butler’s Gartersnake occurrences map


The Butler’s Gartersnake is a small, non-venomous snake, 25 to 57 centimetres long. It has a tiny head and yellow to orange stripes running lengthwise on a dark brown-black background. It looks very similar to the Common Gartersnake and is difficult to distinguish.


The only place in the world where Butler’s Gartersnake is found is in the lower Great Lakes region. In Ontario, this snake is concentrated in two areas:

  • within 10 kilometres of the Detroit River, Lake St. Clair, the St. Clair River, and Lake Huron from Amherst Point to Errol, in Essex and Lambton counties
  • Luther Marsh, Dufferin and Wellington counties.

Population sizes can vary. Estimates done at several sites in Ontario in 1997 ranged between 50 and 900 snakes. At some sites it is considered to be locally common.


The Butler’s Gartersnake prefers open, moist habitats, such as dense grasslands and old fields, with small wetlands where it can feed on leeches and earthworms. Burrows made by small mammals and even crayfish are sometimes used as hibernation sites, called hibernacula. This species is also commonly found in rock piles or old stonewalls.


The most significant threat to the Butler’s Gartersnake is the loss of tallgrass prairie and other grassland habitat due to development in the highly urbanized areas where this species exists. Habitat fragmentation is also a problem since this sedentary snake is unlikely to cross large stretches of unsuitable habitat. Road mortality is another threat.


The Butler’s Gartersnake is protected under Ontario’s Endangered Species Act and the federal Species at Risk Act. This species has also been designated as a Specially Protected Reptile under the Ontario Fish and Wildlife Conservation Act.

What You Can Do to Help the Butler’s Gartersnake

  • The Ministry of Natural Resources tracks species at risk such as the Butler’s Gartersnake. 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.
  • 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.
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Although species at risk are protected, poachers have been known to capture individuals for the pet or food trade. Butler’s Gartersnake may be inadvertently advertised and sold as a Common Gartersnake in pet stores, due to its close resemblance to this and other gartersnakes. Never buy snakes that have been caught in the wild and never buy a native species of any kind that’s being sold as a pet.
  • 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. If it is safe to do so, help snakes across the road in the direction they were headed.
  • Private land owners have an important role to play in species at risk recovery.If you find Butler’s Gartersnake on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • The Canada-Ontario Farm Stewardship Program is available to farmers registered under the Canada-Ontario Environmental Farm Plan to encourage greater protection and conservation of habitat for species at risk. Find more information at www.omafra.gov.on.ca/english/environment/efp/efp.htm.
  • 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?

The Butler’s Gartersnake is non-venomous, as are all of Ontario’s snakes except for the rare Massassauga rattlesnake. The gentle Butler’s Gartersnake will never bite unless handled roughly.

Did you know?

The Butler’s Gartersnake exhibits a peculiar behaviour called side-winding. When excited, it will vigorously wriggle from side to side, making little forward progress.

Did you know?

This species feeds primarily on earthworms, which are not native to Ontario and were introduced by Europeans.

Did you know?

The Butler’s Gartersnake is “ovoviviparous”, which means it gives birth to live young! Instead of laying eggs in nesting material, the eggs are incubated inside the female. Females give birth in mid-to late summer to four to 20 young that are smaller than a pencil.

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.