Prevalence of human‐caused mortality in an unhunted cougar population and potential impacts to management

Abstract

ABSTRACTCougar (Puma concolor) populations have expanded in many western areas of the United States. The Black Hills cougar population naturally recolonized the area and cohabitates within an ecosystem heavily dissected by roads and human activity. Assessing mortality characteristics and determining survival of cougar populations is critical for managing and conserving this species. Our objectives were to assess cause‐specific mortality and estimate survival of the Black Hills cougar population, in addition to assessing annual mortality through ancillary opportunistic methods. We captured and radiocollared cougars during 1999–2005 to assess survival and cause‐specific mortality. In addition to cause‐specific mortality, we also documented all known cougar mortality opportunistically throughout the study area in conjunction with the South Dakota Department of Game, Fish and Parks. We captured 31 independent‐aged cougars (n = 12 M, 19 F) for analyses. We opportunistically documented 85 mortality events of cougars in South Dakota during 1998–2005. Despite protection from hunting during our study, 61.5% of mortality was human‐induced, in contrast to other studies of unhunted cougar populations that generally attribute natural mortality as the primary mortality source. Male and female cougars exhibited relatively high survival through the course of the study; however, low sample sizes precluded rigorous comparisons of annual survival rates between sex and age cohorts. Proportionally, the largest contributors to cougar mortality were lethal removal by the state agency (e.g., depredation, human‐safety concerns) and vehicular trauma. Continued assessment of cause‐specific mortality and survival will be useful for evaluating effects of future manipulations of this population. The potential effects of human‐caused cougar mortalities should be considered when evaluating management strategies for cougars in landscapes with high propensity for human–cougar interactions. © 2014 The Wildlife Society.