Evaluation of Cougar Predation and Bear Kleptoparasitism on Vermejo Park Ranch, New Mexico
September 2022 - June 2025
- Turner Institute of Ecoagriculture
Over the last 15 years, in response to drought, declining range and riparian conditions, and projected drought conditions in the future, Vermejo Park Ranch (VPR; northern New Mexico) has made an effort to determine the carrying capacity for large ungulates (e.g., elk [Cervus canadensis] and American bison [Bison bison]) of the ranch during an average dry year. Understanding large predator populations and their role in regulating elk (and other ungulate) populations is an important, but relatively unexplored question at VPR.
Vermejo Park Ranch is home to black bears (Ursus americanus) and cougars (Puma concolor). Black bear predation can be a primary source of mortality on elk calves. Similarly, cougar predation can be a significant source of elk mortality. Black bears may benefit from, and negatively affect cougars, through kleptoparasitism of cougar kills, which may indirectly impact prey (ungulate) populations by increasing cougar kill rates to make up for the loss of food resources. The primary goal of this study is to document cougar prey selection on VPR and the influence of bear kleptoparasitism on frequency and volume of cougar prey. We anticipate this information will provide insights on the magnitude of elk and mule deer (Odocoileus hemionus) killed by cougars annually and inform future considerations of predator management to support the mission of VPR.