Herpetofauna: Reptiles and Amphibians of Tommy Thompson Park

It is uncertain when the first herpetiles arrived at Tommy Thompson Park, but they have appeared and established populations at the park. Herpetiles have immigrated to Tommy Thompson Park via several possible routes: though natural or manmade corridors like the Don River valley or hydro rights-of-way, as well as via Lake Ontario and the lakeshore.

Reptiles: Snakes

Ontario’s snakes occupy a wide range of habitats including those found at Tommy Thompson Park. Open grasslands, rocky areas and woodlands are examples of snake habitat that can be found at Tommy Thompson Park. Their success at the park is due to overall habitat improvements as well as enhancements that have targeted their life history processes. One of the biggest limiting factors to establishing snake populations are the availability of hibernacula or underground overwintering dens. While there are many areas suitable for snake hibernacula at Tommy Thompson Park, TRCA constructed a hibernaculum on site to ensure overwintering success. Interestingly, although designed for snakes, one of the first users of this habitat was the resident coyotes who used it as a den for several seasons.

The following snakes have been observed at Tommy Thompson Park:

• Eastern Gartersnake (Thamnophis sirtalis sirtalis)
• Midland Brownsnake (Storeria dekayi wrightorum) & Northern Brownsnake (Storeria dekayi dekayi)
• Eastern Milksnake (Lampropeltis triangulum triangulum)
• Northern Red-bellied Snake (Storeria occipitomaculata occipitomacula)

Gatersnakes are likely the most common reptile at Tommy Thompson Park. Tommy Thompson Park has a significant population of melanistic gartersnakes normally found along the shores of Lake Erie.

Two subspecies of brownsnakes ranges overlap in the Great Lakes area but are difficult to identify, which is complicated by interbreeding, so it is impossible to know which subspecies exists at Tommy Thompson Park. They are probably common at the park, but are not often observed due to their secretive behaviour.

Milksnakes are a species at risk in Ontario and although secretive have occasionally been spotted at Tommy Thompson Park at forest edges and meadow habitats.

Red-bellied snakes are uncommon at Tommy Thompson Park and are also very secretive. They prefer to be covered by leaf litter, woody debris and will even burrow into soil.

Reptiles: Turtles

Turtles are the most visible reptile at Tommy Thompson Park and likely one of the most observable wildlife species at Tommy Thompson Park since they can often be seen basking on logs or rocks on warm summer days. A number of habitat enhancement techniques have targeted turtles; these include the provision of woody material just above water level for basking and the creation of south-facing well drained substrate for turtle nesting.

The following turtles have been documented at Tommy Thompson Park:

• Midland Painted Turtle (Chrysemys picta marginata)
• Red-eared Slider (Trachemys scripta)
• Common Snapping Turtle (Chelydra serpentine)
• Blanding’s Turtle (Emydoidea blandingii)
• Northern Map Turtle (Graptemys geographica)

Painted turtles are the most common species of turtle at Tommy Thompson Park. They can be found in all aquatic areas of the park; particularly where half-submerged logs or rocks can be used for basking. A similar species is the red-eared slider, an introduced species. They are commonly kept as pets and every year some are unfortunately and irresponsibily released into the wild where they not only compete with native turtles, but may also spread disease. Please never release any wildlife, native or exotic, into the wild – they may not be able to survive and may have significant adverse effects on the entire food web.

Snapping turtles are also common at the park, but are not regularly oberved due to their highly aquatic nature and their basking behaviour. Look for snappers on the surface of the water with just the very top of their carapace exposed. A radio telemetry project undertaken in the 1990s fitted a snapping turtle caught in Triangle Pond with a radio transmitter and tracked its movements through the Cells, Embayment C and ultimately to the Toronto Islands. Please note it is unlawful to harvest snapping turtles at Tommy Thompson Park.

Blanding’s turtles, a species at risk in Ontario, have been observed on multiple occasions and with increasing regularity at Tommy Thompson Park. These turtles are considered semi-aquatic and prefer marshy areas with shallow water, but will also cross land to reach the next wetland. The mosaic of aquatic habitats at Tommy Thompson Park make it ideal for Blanding’s turtles, therefore it is not surprising that sightings have become more regular as habitat improvements continue.

The Northern map turtle is also a species at risk in Ontario and has been documented several times at Tommy Thompson Park. Since they prefer large water bodies and may swim long distances, it is possible that Tommy Thompson Park is a common stopover for this species.


Ongoing habitat enhancement projects at Tommy Thompson Park are designed to increase amphibian habitat by creating and protecting permanent and seasonally flooded pools critical for amphibian breeding. The following three amphibians have been documented as successfully breeding at Tommy Thompson Park. Look for adult toads and leopard frogs in the meadow areas of the park and look for green frogs in wetlands especially at the shorelines of marshes like the Cell One Wetland.

• American Toad (Bufo americanus)
• Northern Leopard Frog (Rana pipiens)
• Green Frog (Rana clamitans)