Butler’s Gartersnake

Thamnophis butleri
Species Status: Endangered in Canada
Action Required:  Reintroduction, population augmentation and translocation

Butler’s Gartersnake (Thamnophis butleri)

Despite its smaller size and secretive behavior, the Butler’s gartersnake has a smaller range than most of Ontario’s snake species. Although it looks very similar to other Ontario snakes, the Butler’s gartersnake is unique in its diet, habitat, and range.

Easily confused with other striped snakes like the eastern gartersnake or northern ribbon snake, Butler’s gartersnake can be identified by comparing the location of the lateral stripe. The Buter’s gartersnake is also smaller than other Thamnophis species in Ontario, with a shorter length and narrow head and neck compared to the eastern gartersnake. This shy snake which is often hiding under objects, and uses this lateral stripe and a side-winding movement when startled to confuse predators and make itself difficult to capture.


Butler’s gartersnake habitat in Canada includes tallgrass prairie, old fields, and grassy areas often close to wet or damp environments. Although Butler’s gartersnakes are typically only found in open grassy areas, they can still be found in both natural and human disturbed habitats. Historically, the Butler’s gartersnake’s diet consisted largely of leeches, but this species has since shifted its diet almost completely to non-native earthworms.


The Butler’s gartersnake has a very small range, one of the most restricted of all snakes, limited to Southern Ontario around the lower great lakes south to Indiana and Ohio. Ontario accounts for approximately 16% of its global range, which is largely limited to the Windsor and Sarnia regions.


Butler’s gartersnakes face many threats in their small Ontario range, mostly associated with human activities that reduce habitat availability and quality. Urbanization results in habitat loss and fragmentation of remaining small populations. Road separate populations from one another and contribute to mortality from vehicle strikes. Additional threats to Butler’s gartersnakes include intentional killing by people, and illegal collection for the pet trade. The combination of these threat, coupled with the isolated nature of remaining colonies in Ontario, has resulted in an ongoing decline in the Canadian range of the Butler’s gartersnake as local populations go extinct.


Recommended Recovery Actions

The federal Recovery Strategy for the Butler’s gartersnake focuses heavily on habitat protection, restoration, and threat mitigation, along with monitoring of populations and increasing public awareness. Recommended actions include implementing best management practices, establishing long term monitoring, public outreach and education. The Ontario Provincial Government Response Statement’s actions include the need to conduct research to determine the effectiveness of threat mitigation techniques, recovery approaches and best management practices, including techniques for salvage and translocation.

What we are doing

Butler’s gartersnake is on Wildlife Preservation Canada’s priority list for potential future action. Find out how we are currently saving other Canadian reptiles and amphibians, and how you can make a difference.

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by Wildlife Preservation Canada
Butler’s Gartersnake