Last week, coinciding with the Society of Conservation Biology's biennial international conference, Sawaya, Clevenger and Kalinowski published a paper in the journal Conservation Biology detailing what genetic testing on 10,000 hair samples showed about the demographic effect the Banff crossings have on area bear populations.
Their results offered an encouraging assessment that a highway punctuated with 25 different crossings did not fragment the habitat in a way that prevented bears from seeking food, shelter and dispersal areas on either side of the Trans-Canada Highway.
"This is a landmark study because it's the first time anyone has done extensive genetic sampling to address unanswered questions about the use of highway crossings by bears," Clevenger said. "We knew that bears used the crossings, we just didn't know how many, what percentage of each species' population uses them, whether there is a preference by males or females to use crossings, and if there was a gender or species preference for overpasses or underpasses."
Another paper from the study due this fall will break down what ecologists call "gene flow" between bear populations in the Banff ecosystem. That data should help gauge how well the crossing structures perform in allowing different bears to find mates in an ecosystem bisected by a major highway.
"By collecting the genetic data on each bear using the crossings, we have a much more powerful tool for gauging the effectiveness of the crossing structures to provide connectivity within the ecosystem," Clevenger added.
In 2006, Sawaya, Clevenger and Kalinowski began setting out noninvasive hair snags strands
|Contact: Evelyn Boswell|
Montana State University