Date of this Version
Rocky Mountain National Park (RMNP) has supported a small black bear (Ursus americanus) population of low productivity. Increased visitor use of the park and development around its periphery could lead to a reduction in population viability of RMNP’s bear population or could increase the potential for human–bear conflict. Therefore, we investigated contemporary survival and productivity parameters for RMNP’s black bear population from 2003 to 2006 and compared these values to historic levels (1984–1991) and population means throughout the western United States to clarify the current status of RMNP’s bear population. The contemporary black bear population showed signs of earlier reproduction and higher cub survival when compared to historic bears; litter size and adult and subadult survival were similar between contemporary and historic periods. Increased productivity of the contemporary population was likely due to better nutritional condition of reproductive females, which showed significantly higher body condition index scores, body fat, and weights, which are likely due to observed greater use of anthropogenic food sources. The population of black bears in RMNP may have greater growth potential than was observed historically, decreasing the reliance on immigration from adjacent populations. However, increased human–bear conflicts associated with greater use of human-associated habitats in RMNP may negate some of the advantages of increased population productivity because of removal of problem bears.