TOPOGRAPHICAL CONSTRAINTS AND HOME-RANGE QUALITY

The topography of an area affects the animals that live in it. Using d igitized topographic maps of our mountainous study area in North Carol ina, USA, and using radio telemetry data for locations of black bears Ursus americanus, we tested the hypotheses that topography influences home ranges of black bears and that topography affects access to resou rces by black bears. Use of space by bears correlated positively with steepness of slope but negatively with relative elevation. The perimet ers of bears' home ranges aligned with ridges and valleys more than ex pected by chance and home ranges were oriented on major topographic fe atures, such as watersheds and basins. Bears' home ranges had lower re source values than was optimal for their home range locations and acce ss to resources was limited by topography. Ignoring topography may lea d researchers to misunderstand the ecology and behavior of animals tha t live in mountainous areas.