Monitoring & Mitigating Road Mortality
Each year, from spring to fall, Adopt-A-Pond staff go out in pairs to look for animals along the roads near the Toronto Zoo. The team walks up and down the road looking for any animals (with a focus on reptiles and amphibians) that are on the road or the shoulders. Unfortunately, most of the animals that they find have been hit by cars and have not survived. We collect this “road mortality” data and use it to identify areas where there are high numbers of animals crossing the road, called “mortality hotspots”. While grim, this data tells us where the best places are to focus mitigation efforts.
Two Adopt-A-Pond staff record the road temperature during a road survey. We use this information to see if road temperature is related to how many animals are on the road that day.
Roads separate or fragment habitat, which leads to animals attempting to cross roads to reach various areas of their habitat, often to meet their different needs as they go through their life stages and annual cycles, increasing the risk of wildlife-vehicle collisions. Since reptiles and amphibians can’t cross roads as easily as birds and mammals, road mortality is a major threat to many species. Freshwater turtles need a variety of habitats throughout the year, and cross roads to reach mates, nesting habitat, or overwintering habitat. Snakes also cross roads to reach different habitats, especially in the spring and fall when leaving or returning to their hibernation sites (hibernacula). Snakes are also known to use roads to bask (heat up their bodies) and are generally not good at avoiding cars. Amphibians, like frogs and salamanders, disperse from their birth ponds to new habitats. These risks are heightened in urban areas like the GTA, where road networks are extremely dense. Did you know that you can’t go more than 1.5 km in a straight line in southern Ontario without crossing a road?!
Adopt-A-Pond has been surveying road segments near the Toronto Zoo since 2017, and the Ontario Road Ecology Group (OREG) did surveys in 2010 and 2011. This data has identified a number of road mortality hotspots close to the Toronto Zoo. Adopt-A-Pond continues to work with local partners, including Parks Canada, Toronto and Region Conservation Authority, City of Pickering, Ministry of Natural Resources and Forestry (MNRF), and Ministry of Environment, Conservation, and Parks (MECP), to address these mortality hotspots.
L: The Adopt-A-Pond team installing the fencing in May 2019. R: Image shows the fencing and how it directs animals into the concrete culvert to cross under the road.
One of our first projects took place in 2019, with funding from the Species at Risk Stewardship Fund (MNRF, MECP). We worked with partners to install fencing that was tall enough to prevent small and medium sized animals from crossing the road. The fencing was installed on both sides of the road and connected to a concrete culvert that allows animals to safely cross under the road. This project restored habitat connectivity while decreasing road mortality, as there was no road mortality along this stretch in 2019. In 2020, we were not able to continue with road surveys due to COVID-19, but we were able to successfully gather evidence of animals, including turtles and snakes, using the culvert to cross! We partnered with Eco-Kare International to install wildlife cameras in the culvert to capture these images.
Animals using the culvert. L: Eastern gartersnake; M: Midland painted turtle; R: Mallard ducklings in the evening.
As Adopt-A-Pond continues to monitor road mortality, we’re committed to working with partners to implement more mitigation projects in the future to help prevent road mortality and make the roads safer for all animals and drivers! This includes adding more fencing around local wetlands and installing wildlife crossing signs.
You can also help reduce road mortality! The best way to do that is to help turtles,snakes, frogs, and salamanderscross the road. Be on the lookout all summer long, but especially in the spring and fall when reptiles and amphibians are moving between habitats! Remember to always make sure that you’re safe before helping an animal cross the road.
You can also share your observations of turtles and frogs on roads with us through Turtle Tally and Frog
L: Example of Adopt-A-Pond’s wildlife crossing signs; R: Screenshot from the Adopt-A-Pond app