Species At Risk

Gray Ratsnake

(Pantherophis spiloides)

Endangered (Carolinian population)
Threatened (Frontenac Axis population)

Gray Ratsnake


The Gray Ratsnake, is also commonly known as the Black Ratsnake or the Eastern Ratsnake. It is non-venomous and is Ontario’s largest snake, reaching up to 2 metres in length. This elegant snake has a shiny black body with a white chin and throat. The belly is white or yellowish with dark spots that often produce a checkerboard pattern. Young snakes are grey with dark blotching on the body and tail.

Action we are taking:


Gray Ratsnakes are widely distributed throughout the eastern and central United States, extending as far north as southern Ontario. There are two widely separated populations in Ontario: the Carolinian in southwestern Ontario and the Frontenac Axis in southeastern Ontario.


The two populations of Gray Ratsnake in Ontario can be found in different types of habitat.

The Frontenac Axis population requires a variety of habitat types including deciduous forests, wetlands, lakes, rocky outcrops and agricultural fields.

The Carolinian population is found in a mix of agricultural land and deciduous forest, preferring habitat where forest meets more open environments.

Adults are strongly attached to their home ranges and often return to the same nesting and hibernation sites. They often lay eggs in logs or compost piles that serve as incubators. Sometimes several females will use the same site to deposit eggs.


The most significant threats to the Gray Ratsnake are the loss and fragmenting of habitat and persecution by people. Other serious threats include motor vehicles and the destruction of suitable hibernation sites. Since ratsnakes hibernate in groups at the same site year after year, destroying these sites can have a large impact on the local population. The Gray Ratsnake is slow to mature and reproduce which may also inhibit recovery of this species.


The Gray Ratsnake and its habitat are protected under Ontario’s Endangered Species Act.

What You Can Do to Help the Gray Ratsnake

  • The Ministry of Natural Resources tracks species at risk such as the Gray Ratsnake. 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. Keep the danger of snakes in perspective: All of Ontario’s snakes are non-venomous, except for the very and shy Massasauga Rattlesnake.
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • 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.
  • Every year, snakes all over the province must cross busy roads. Watch for snakes on the roads, especially between May and October.
  • Private land owners have an important role to play in the recovery of the Gray Ratsnake . If you find a Gray Ratsnake or nest on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • There is a new program geared to eligible farms registered under the Canada-Ontario Environmental Farm Plan to encourage greater protection and conservation of habitat for species at risk. www.omafra.gov.on.ca/english/environment/efp/efp.htm .
  • Visit the Toronto Zoo Adopt-a-Pond website to learn more about Ontario’s rare snakes, their habitat and related conservation initiatives. www.torontozoo.com/Adoptapond
  • o Register with the Herpetofaunal Atlas program to receive e-mail newsletters, event notifications, and other important updates about the Herpetofaunal Atlas project as it develops. Visit their website to see how you can participate and learn more about Ontario’s reptiles and amphibians. (www.ontarionature.org/herpetofaunal_atlas.html) .

Did you know?

If two male ratsnakes are interested in the same female, the males will compete in physical combat for the right to mate.

Did you know?

During the breeding season, females will mate with multiple males and produce a clutch of eggs sired by different fathers.

Did you know?

This snake is an excellent climber. Watch for the Gray Ratsnake overhead, where it may be up a tree or bush sunning, preparing to shed its skin or hunting for prey.

Did you know?

The Gray Ratsnake is a constrictor and feeds mostly on small mammals and birds. Since it spends some of its time in trees, it is an efficient predator of bird nests.

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.