Species at Risk

Gray Ratsnake

Gray Ratsnake – Carolinian Population

(Pantherophis spiloides)


Status in Canada: Endangered

Status in Ontario: Endangered

Status at SWCR: Extremely rare

The young have dark splotches over a lighter grey background, but they become mostly black as adults.

Quick Facts:

  • It is Ontario’s largest snake, and can grow over 2m long!
  • They are long-lived snakes, and can grow as old as 30!
  • They hibernate in large groups called hibernacula: disruption of these hibernacula can put entire populations at risk!

Threats at the St. Williams Conservation Reserve:

Habitat Degradation: fragmentation by roads and the expansion of agriculture are making habitat unsuitable for this species.

Direct Mortality: due to agricultural activities, persecution, and collisions with vehicles along roads or trails.

Activities that can harm Gray ratsnakes and damage their critical habitat include:

  1. Activities that can introduce or encourage the growth of invasive plants, such as dumping of garden waste and off-trail ATV use.
  2. Activities that fragment habitat such as inappropriate trail or road development.
  3. Activities that interfere with understory shrubs, unauthorized plant collecting and off-trail ATV use.
  4. Off-trail recreational activities that damage or displace individuals or nests, such as persecution, crushing under vehicles, and collecting.

St. Williams Conservation Reserve management practices:

  • Population monitoring
  • Enforcement of unauthorized trail use

What you can do to help:

  • Follow the  code of conduct for recreational activities in the Conservation Reserve and know and respect the current trail-use regulations.
  • Report sightings to the SWCR CC, or the Natural Heritage Information Centre.
  • Report unauthorized trail use or any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).

More information:

Species At Risk Public Registry Profile

Ontario Species at Risk Profile


Funding for this project was provided through the Species At Risk Stewardship Fund