Black bears (Ursus americanus)are among the largest and least frequently seen mammals in Rocky Mountain National Park. The opportunity to see one in the wild is a never-to-be-forgotten experience for many park visitors. Given their size and charisma, it may be surprising to some how little we know about the park's only remaining bear species. (Grizzly bears had been eradicated from the park by the time it was created in 1915.)
Between 1984 and 1991, due to a rise in bear sightings in the park, staff conducted a study of the bears. From that study, the average weight for adult female bears was 121 lbs. and for males was 175 lbs.,about 1/2 to 2/3 the weight of black bears in west-central Colorado. Females produced their first cubs at age seven or eight. Bears in other parts of Colorado produce their young at age five or six, and in Idaho at about age five. In addition to producing young later in life, park bears also tended to have fewer cubs than bears in other parts of Colorado. Estimates suggested that between 20 and 35 bears lived in the park. Those bear densities were 1/6 of those in west-central Colorado to 1/12 of those in other Rocky Mountain states. The study suggested that the park had naturally poor habitat for bears, but attracted them because hunting was, and remains, prohibited.
But what is the situation now? We honestly don't know. Because of our lack of knowledge and the park's commitment to managing our resources based on good science, bear research started again in 2003. Because the current effort is more focused, we hope to be able to have a much more accurate estimate of bear numbers, sizes, ages, and genders. We hope to understand more about what our bears eat and where they live. Most importantly, for both the bears and our visitors, we hope to understand how to reduce conflicts between them.