Kerri Krawchuk

Is niche separation between wolves and cougars realized in the Rocky Mountains?

Multiple carnivore species can have greater population limiting effects than single carnivores. Two coexisting carnivores can only be similar up to a certain extent. I investigate how two carnivores, wolves (Canis lupus) and cougars (Puma concolor), coexist through niche partitioning in the central east slopes of the Alberta Rocky Mountains. Wolf packs spatio-temporally avoided other wolf packs more than they did cougars, while cougars avoided conspecifics as much as wolves. Reinforcing spatial separation, temporally wolves had two crepuscular movement peaks while cougars had just one. Male cougar movements peaked in the late evening and was high over night, while female cougar movement increased throughout the day and peaked in the evening. Female cougars selected different habitat features from male cougars and from wolves during both the day and night, while male cougars had more habitat selection differences from wolves at night. I found some evidence that cougars were more influenced by landscape features than wolves. Differences in the predators’ habitat selection were primarily for prey density contingent upon habitat features, likely related to maximizing hunting efficiency. Both species killed primarily deer (Odocoileus virginianus, O. hemionus), though wolves and male cougars killed and selected more large-bodied ungulate prey, such as elk (Cervus elaphus), moose (Alces alces) and/or feral horses (Equus calabus) than female cougars, who strongly selected for deer. It is advantageous to consider both these species together when building management plans for both predator species as well as for their ungulate prey.