Methods

Carnivores are notoriously difficult to study given their large area requirements, low densities, and elusive behavior. In recent years, noninvasive survey methods (i.e., methods that do not require that animals be captured or even directly observed) have enhanced our ability to study carnivores across expansive landscapes.

Remote cameras, for example, allow us to document the presence of a species in a given area, and hair-snagging mechanisms enable us to collect DNA from carnivores that visit sampling stations. Meanwhile, specially trained scat detection dogs provide a highly effective means for locating scat samples, which confirm species presence and serve as another source of genetic material.

After hair and scat samples are collected in the field, DNA is extracted from them and analyzed by Wildlife Genetics International (Nelson, BC) using standard methods.

Bear hairs snagged on a strand of barbed-wire. Credit: Paula MacKay

Bear hairs are sorted at Wildlife Genetics International. Credit: Paula MacKay

Bear hair samples are processed at Wildlife Genetics International. Credit: Paula MacKay

Landscape genetics—a relatively new field that combines population genetics with landscape ecology—uses the genetic signature from a given DNA sample, coupled with the sample’s original field location, to assign samples (and therefore individuals) to populations.

Landscape genetic approaches are able to make efficient use of the large numbers of genetic samples that can be collected via noninvasive survey methods. These approaches allow us to assess patterns of gene flow and to visualize the effects of movement barriers (e.g., highways) on the genetic structure of populations.