Species at Risk

Eastern Ratsnake

Elaphe obsoleta

What is the status of the Eastern Ratsnake?

Close-up of an Eastern Ratsnake.  It is coiled, with its head resting on its body.
The Eastern Ratsnake is not venomous and its teeth are only 1–2 mm long (shorter than a rose or raspberry thorn.
© Parks Canada / Gregory, J. / 1974

In 1998, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) designated the Eastern Ratsnake as a threatened species in Canada. This means that it is protected under the Species at Risk Act.

In addition, under Ontario law, killing, trapping or harassing the Eastern Ratsnake is illegal.

The species is also listed as threatened in several U.S. states.

Why is the Eastern Ratsnake in danger?

Eastern Ratsnake populations in Canada are threatened because:

  • In the past 200 years, human activities such as urbanization and intensive agriculture have destroyed and fragmented ratsnake habitat.
  • Ratsnakes reproduce at a slow rate and, in small populations, the death of a few individuals may have major consequences.
  • Ratsnakes gather in large numbers (30–60 individuals) to spend the winter in winter shelters, or hibernacula. Destroying a hibernaculum can wipe out an entire population.
  • In fall and spring, ratsnakes seek warm, sunny spots to bask such as roads, where they can be run over by cars.
  • They are persecuted because people are afraid of snakes or hunt or trap them.