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

Abstract

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 non‐sanctuary bears. Monte Carlo analyses of Leslie matrices showed that the bear population in the sanctuary would be stable if cub survivorship, p0, was about O.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 O.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.

Edge‐Core Effects and the Effectiveness of Traditional Reserves in Conservation: Eurasian Badgers in Doñana National Park

“…Carnivore mortality can be accidental, as in road kills and nonselective trapping, or intentional, as in hunting and poaching. Accidental killing in traps set for other species is a main concern in the conservation of small-and medium-sized carnivores, especially if the target species is common and a rare carnivore is taken (Schreiber et al 1989), whereas for larger species direct hunting and poaching are the main problem ( McLellan 1989;Powell et al 1996;Beringer et al 1998;Seidensticker et al 1999). This human-mediated mortality is frequently reported at administrative borders of reserves for local populations.…”

Full Issue

“…For an area of 276 km 2 in Amazonian Peru, Begazo and Bodmer (1998) estimated that harvest rates of M. tuberosa and P. cumanensis were unsustainable, but harvest of P. jacquacu was within sustainable levels. The persistence of hunted populations also depends on the presence of nonhunted, adjacent areas that may function as refuges or populations sources, although the hunted area may be a population sink (Powell et al 1996).…”

Modeling black bear population dynamics in a human-dominated stochastic environment

“…Natural food failures and their impacts on population vital rates are mentioned in several bear studies (Beck, 1991;Bridges et al, 2011;Powell et al, 1996;Rogers et al, 1976), but our study explicitly incorporated them into the population model. We found that increasing the frequency of poor natural food years increased the differences between population growth rates of the Baseline scenario and both Removal scenarios.…”