Carnivore and ungulate responses to cattle in a grazed forest ecosystem

Habitat disturbance, a leading threat to biological diversity, comes in many forms and can alter the behavior of wildlife and reduce the amount of suitable habitat. Livestock grazing, a form of habitat disturbance, is the most widespread influence on native ecosystems of western North America. Research on the impacts of introduced domestic herbivores on wild carnivores and ungulates varies, and the degree to which wildlife species are affected is often species-specific. I used remote trail cameras to compare the activity patterns of black bears (Ursus americanus), coyotes (Canis latrans), bobcats (Lynx rufus), mountain lions (Puma concolor), mule deer (Odocoileus hemionus), and Rocky Mountain elk (Cervus canadensis nelsoni) in areas with and without cattle grazing before, during, and after the cattle grazing period in northeastern California. Bobcats and mountain lions had low overlap of activity with cattle. Bobcats shifted their activity patterns to have less overlap with cattle in allotments during the grazing period, and their relative probability of activity was greater in areas where there were no cattle present. Black bears, coyotes, and mule deer had high levels of overlapping activity with cattle. Deer shifted their activity patterns resulting in higher overlap with cattle in allotments during the grazing period. Relative probability of black bear activity was greater in areas without cattle presence. Conversely, relative probability of coyote activity was greater in areas with cattle. Elk activity moderately overlapped with cattle activity. These findings suggest that carnivores and ungulates display varying levels of sensitivity and behavioral plasticity in response to the presence of domestic herbivores on the landscape. Managers should carefully consider possible impacts to local wildlife populations when determining grazing timing and stocking rates, especially when a species is in decline or the habitat is in continuous degradation