Demographic Analyses of a Hunted Black Bear Population with Access to a Refuge

• Published in: Conservation biology 1996-02, Vol.10 (1), p.224-234
• Main Authors: Powell, Roger A., Zimmerman, John W., Seaman, D. Erran, Gilliam, James F.
• Format: Article
• Language: English
• Subjects: Age; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Bears; Biological and medical sciences; Black bears; Conservation biology; Conservation, protection and management of environment and wildlife; Demecology; Demography; Depopulation; Fecundity; Fundamental and applied biological sciences. Psychology; Mammalia; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Poaching; Population studies; Ursus americanus; Vertebrata; Wildlife management
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1046/j.1523-1739.1996.10010224.x

Studying one of two bear species not experiencing widespread population decline, provides insight into the population responses of the six bear species that are in decline and into responses of other long-lived species for which data are difficult to collect. Black bear (Ursus americanus) sanctuaries were established in North Carolina (U.S.) in 1971 to protect core populations of bears and to provide dispersing bears for hunting. Population index values, derived from counts of bears visiting bait stations, were significantly greater inside the Pisgah Bear Sanctuary than outside and were greater along trails than along roads. Survivorship of bears outfitted with transmitter collars was greater for sanctuary bears alone than for sanctuary plus nonsanctuary bears. Monte Carlo analyses of Leslie matrices showed that the bear population in the sanctuary would be stable if cub survivorship, p0, was about 0.7, and the population in the sanctuary plus the surrounding area would be stable if p0 was about 0.83. Estimates of litter survivorship in North Carolina indicate, however, that p0 can not exceed 0.71. Overall, the matrix analyses indicated an ultimate population decline in the total bear population (sanctuary plus surrounding area). The population index of the bait station did not show a discernible decline. The Pisgah Bear Sanctuary provides dispersing bears for hunters and provides some protection for the resident bears. The sanctuary may not, however, provide resident bears with enough protection to maintain a viable breeding population within its boundaries. Reducing human access to bears and their habitat appears crucial, either by making large sanctuaries or by eliminating roads.