Squashed by cars, slaughtered in their nests, Canada’s big snakes are under siege

Foldable antenna in hand, radio receiver and backpack slung over his shoulders, Mathieu Lecompte is prowling through Thousand Islands National Park in search of the elusive gray ratsnake. Reaching lengths of 2.5 metres, the gray ratsnake, with its whitish belly and head, is one of Canada’s largest.

The park in Mallorytown, Ont., is the only national park where the snake is found, said Lecompte, a Parks Canada resource management officer working on its resource conservation team. “It’s really an important part of the conservation program here.”

Lecompte’s work is part of Parks Canada’s “On the Road Again” project aimed at protecting snakes and turtles across western and central Ontario. By learning more about the gray ratsnake, the project hopes to develop better ways to protect it.

With the help of Parks Canada staff and a local veterinarian, Lecompte and his team implanted five adult gray ratsnakes with a radio-based tracking system, which emits a sound that grows louder as researchers carrying the receivers draw near.

“They spend their winter in what is called a hibernaculum, below the frost line, where large groups of gray ratsnakes hibernate together in groups, which are very important to preserve,” explained Lecompte. “The most important thing we’re looking at is locating their hibernation site.”

An Uncertain Future

Parks Canada classifies the gray ratsnake as a threatened species in the Great Lakes/St. Lawrence region. Its habitat is increasingly at risk from development and road network expansion, according to Parks Canada and the Committee on the Status of Endangered Wildlife in Canada’s (COSEWIC) Assessment and Status Report on the Gray Ratsnake.

“There is a reason why you don’t have ratsnakes in town [and] it’s because the ones that were there died. They died on the road or because people killed them because they still don’t like snakes,” explained Lenore Fahrig, a Chancellor’s Professor in the biology department at Carleton University. As development expands, more snakes will die, and their survival rates and population numbers will drop even lower, Fahrig said.

Vehicle traffic is the snakes’ greatest threat in this region and there is some evidence people sometimes deliberately run over or intentionally destroy their hibernacula, the COSEWIC report states.

The greatest risk for the snakes — which are harmless to people and eat small mammals, frogs and bird eggs — to be run over is in the spring when they emerge from hibernation and lie on warm roads to regulate their body temperatures.

The Ford government is planning to expand Highway 401 east and west and environmental impact studies are still in progress.

Given its proximity to Highway 401, the wildlife in Thousand Islands National Park have an increased probability of mortality, said Stephen Lougheed, professor and Baillie Family Chair in conservation biology at Queen's University. “The more you bisect an area, the more challenging it is for the wildlife,” he added.

With the future of gray ratsnakes in the region so uncertain, Parks Canada is attempting to educate park visitors and local landowners about the importance of preserving snake habitat. Lecompte and Parks Canada partnered with the Leeds-Grenville Stewardship Council to create guides for landowners on how to coexist with the gray ratsnake.

“There is an increasing disconnect between people and urban environment and even somewhat rural environment and nature,” said Lougheed. “If we want people to value our natural heritage, we have to really engage thoughtfully in education, and that’s an incredibly important thing that we should be talking about here.”

Turning off his receiver and collapsing his portable antenna, Lecompte makes his way back to the main road, ending a day of tracking. In a few short weeks, the snakes will have dug themselves into hibernacula, where they will spend the winter.

“For this project especially, it's focused on species recovery, but [the public education side is] also really important to help teach people about this amazing species at risk that’s unique to the Thousand Islands and that really needs help,” he said.