New research sheds light on roads and turtle mortality

Roads are flat-out dangerous for turtles, but a study of Ottawa’s suburban routes suggests a silver lining for life near the fast lane. For painted turtles laying eggs along roadsides, more traffic means fewer predators, fewer attacks on nests, and better egg survival.

“Roadkill is a major issue for turtles…but predators are also negatively affected by roads,” says Rowan Murphy, who tracked the interplay of turtles, traffic, and predators for her Master’s degree in biology at Carleton University. She found the whoosh of cars is scaring egg-napping skunks, foxes, and raccoons away from turtle nests, and improved hatchling survival could compensate for adult roadkills.

It’s a hard knock life: Ontario’s turtles in trouble

Testing the concept in 2019, Murphy packed 2,400 quail eggs into 600 ersatz “nests” and distributed them in natural areas and roadsides on the outskirts of Ottawa. Then she waited while predators brunched. Roadside nests suffered 26 per cent less predation than nests grouped in natural areas.

Murphy cautions that this benefit may not outweigh other harms from traffic, including contaminants from exhaust, tire particles and spills. Excessive heat from pavement and gravel can also skew the sex ratio of hatchlings, producing more females. And as Kari Gunson, a road ecologist for consulting firm Eco-Kare International points out, once hatchlings emerge, they’re still exposed to traffic. “Turtles are especially prone to road mortality because of roadside nesting, and their ‘hide in shell’” response to threats, she says.

How to ID Ontario’s turtle species

Gunson and Murphy agree the best option is keeping turtles off the turnpike. New roads could be steered away from turtle habitat. Fencing and culverts could guide turtles to safe nesting sites. For both turtles and cars, it’s best to stay in our own lanes.

PSA alert! Slow down for turtle areas when driving. If you see an injured turtle, contact the Ontario Turtle Conservation Centre.