The sight of a road can strike fear into the heart of one of Canada’s toughest predators, according to new research on wolverines in Alberta.
Wolverine biologist Matt Scrafford spent three winters capturing a number of these wily predators in northern Alberta. The wolverines were then fitted with GPS collars and tracked across an area of the province crisscrossed with logging and oil and gas service roads.
Scrafford, who joined Wildlife Conservation Society (WCS) Canada in 2017, had a strong hunch that the wolverines would do their best to stay away from the roads, but he sought to create a more detailed picture of how wolverines react to roads. He and his team tracked not only where the wolverines went in their Alberta forest habitat, but also how they behaved in different parts of their extensive territories. To do that, they used the GPS tracking to also calculate how quickly wolverines were moving and how much time they spent in specific areas, especially near roads.
Wolverines require very large areas of habitat to scavenge, hunt, and raise young. When an area has a high density of resource access roads (i.e. for oil and gas exploration, forestry and mining), it becomes risky for wolverines to travel and makes it difficult for the animals to find large, intact areas where the risk is lower. Further, roads can also increase the time it takes a wolverine to navigate through its territory if the animal is inclined to avoid roads.
Scrafford’s research, published this month in Behavioral Ecology, indicates that wolverines both avoid roads and, when in the vicinity of roads, move quickly to reduce the time spent near them. Their actions suggest that they perceive roads and surrounding areas to be high-risk areas. Wolverines are not unique in their apprehensions about roads, but different species react differently when encountering roads. For example, some pause and assess, some speed across or away, and others simply avoid roads altogether. Wolverines, Scrafford found, tended to avoid roads, but also picked up the pace when in the vicinity of roads, making them “speeders and avoiders.”
But Scrafford also wanted to know if behavior changed depending on the type of road. To do this, he had to quantify traffic levels on everything from lightly used resource roads to busy highways. Fixed cameras left in place over a period of time were used to calculate traffic levels on backcountry roads in the study area, while provincial data was used to estimate traffic flow on a busier highway running through the area.
Not surprisingly, Scrafford’s team found that wolverines spent as little time as possible near busy roads. But, interestingly, they found that wolverines also had a strong tendency to avoid even lightly used roads. This behaviour may be linked to a fear of being exposed to predators while crossing resource roads — particularly wolves, which may use the roads to hunt. This fear might not be unjustified: during his fieldwork, Scrafford found three male wolverines killed by wolves near winter roads.