From Wildlife Extra:
Wildlife crossings help bears find mates
February 2014: The wildlife crossings of the Trans-Canada Highway have helped bears safely cross the road and find mates on the other side of the road, research shows.
Roads connect human populations across vast distances but they can have an adverse effect on the populations of wildlife for as well as being possible victims of traffic accidents. Noisy traffic can also deter animals from approaching busy highways and groups can become isolated and fragmented with little chance for genetic mixing.
To counteract this fragmenting effect wildlife underpasses and overpasses have been built along major roads including the Trans-Canada Highway, Canada’s primary east-west transportation route. The highway runs through Banff, Canada’s oldest national park which is home to an array of wildlife, including two species of bear.
The researchers studied 20 of the 25 bear crossings along the Trans-Canada Highway using hair-snagging traps.
Through collecting thousands of hair samples over their three year study the team were able to identify hundred of bears including 15 grizzlies and 17 black bears who crossed, sometimes frequently, the Trans-Canada Highway. They found that bear populations were not isolated on either side of the road and that male and female bears from both species were using crossings to successful migrate, breed and carry genes over the road.
The team behind this study say young bears may be learning to use the crossings from their mothers.