Estimates of Population Density and Growth of Black Bears in the Smoky Mountains

To estimate population abundance, data were collected from 1,239 black bears (Ursus americanus) trapped in 3 areas of the Smoky Mountains (SM), 1972-89. Bears were tagged, tattooed, and released, and using the Jolly-Seber open population model, density estimates ranged from 0.09 to 0.35 bears/km2. Year-to-year density estimates and the observed rate of growth (0-2%) indicated a stable to slightly increasing population. The predictions of the population model, BEAR, indicated the importance of hard mast to this population; in years of good mast, the numbers of bears increased, whereas in years of poor or varying mast availability the population declined. Int. Conf. Bear Res. and Manage. 9(1):253-261 Habitat loss and fragmentation constitute considerable threats to wildlife populations (Dasmann 1981, Harris 1984). Black bears have lost more than 90% of their original range in the southeastern United States (Pelton 1986), and much of what remains lies in scattered tracts of public lands (Maehr 1984). Due to their sensitivity to habitat alterations, black bears are considered environmental indicators (Pelton and Beeman 1975). As such, and to assist proper management, an understanding of population density and growth is desired. In portions of the Smoky Mountains (Smokies), such as Cherokee (CNF) and Pisgah (PNF) National Forests, black bears are legally harvested, though poaching is a significant source of mortality as well. In Great Smoky Mountains National Park (GSMNP) legal harvest of bears has been prohibited for more than 50 years, but poaching persists. To better understand the survival, movements, density, and reproduction of bears of these mountains, researchers have collected information for nearly 20 years. The purpose of this analysis was to assimilate the collected information and characterize the black bear population in terms of density and growth. The authors gratefully acknowledge a number of contributions. Many students collected the field data; without heir collective contribution of 20 years of data, this work would not have been possible. Frank Teunissen van Manen kindly provided several of the illustrations; his friendship and support have been appreciated. Our pilot, Bill Kindy, helped locate dens of females. Dr. Ken Pollock, of the Institute of Statistics at North Carolina State University, advised our population estimation efforts. Dr. John Higgins helped in calculating the estimates of population growth. Dr. Dan Johnson and Mark Mathis and his fellow students of East Tennessee State University assisted with the modelling. Jim Wentworth of the University of Georgia, Greg Wathen, Doug Scott, David Whitehead of the Tennessee Wildlife Resources Agency, Bill Cook of the National Park Service, and John Collins of the North Carolina Wildlife Resources Commission provided the data on hard mast; Steve Pozzanghera contributed, in large part, to its analysis. A number of people assisted us in the field and for this and their friendship, we are thankful. Last, but most important, we are indebted to our families for their support in this and other endeavors. The project was funded through McIntire-Stennis grant No. 39, the Department of Forestry, Wildlife, and Fisheries and the Graduate Program in Ecology of the University of Tennessee, and the Great Smoky Mountains Conservation Association. STUDY AREA Great Smoky Mountains National Park, visited by nearly 10 million people annually, is located in eastern Tennessee and western North Carolina (Fig. 1). Approximately /4 (506 km2) of the park, the northwest portion, served as 1 study area from 1968 to 1989. The park is characterized by steep ridges, narrow valleys, coves, and fast-flowing streams (King and Stupka 1950). Elevation ranges from 230 to 2,035 m (Pelton et al. 1980). Average temperatures vary from 14? C at low elevations to 8? C at high ones (Shanks 1954). Considered a temperate rain forest (Thorthwaite 1948), the park receives 140 cm of annual precipitation at low elevations and 230 cm at high elevations (Stephens 1969). Six major forest types are recognized (Shanks 1954): cove hardwood, hemlock (Tsuga canadensis), northern hardwood, open oak-pine (Quercus spp.-Pinus spp.), closed oak, and spruce-fir (Picea rubens-Abies fraseri). Understory vegetation is dominated by mountain laurel (Kalmia latifolia), rhododendron (Rhododendron spp.), blueberries (Vaccinium spp.), and huckleberries (Gaylussacia spp.). The Pisgah National Forest study area comprises 114 km2 (Brody 1984) in western North Carolina (Fig. 1). 254 Int. Conf. Bear Res. and Manage. 9(1) 1994