We studied a heavily-hunted population of black bears (Ursus americanus) on the periphery of the bear range in east-central Minnesota in 1991 and 1992. This was one of the few areas in Minnesota where hunting pressure was not controlled by a quota on the number of hunting licenses. We hypothesized that the area supported high harvest levels because it was a population sink supplied by seasonal migrants, dispersing subadult male immigrants, or both from northern Minnesota. However, we captured 7 female and 5 adult male bears during late summer and from radiotracking found that all were residents of the study area. Also, the following evidence indicated that immigration of young males was not sustaining the population: (1) males made up a similar fraction of the harvest in the study area (53.6%) as statewide (53.1%); (2) the rate of decline in the ratio of males to females in each harvested age class, due to high harvest mortality that depleted male numbers faster than females, showed no sign of being retarded by an influx of males; and (3) yearling males, an age group not heavily represented among dispersers, composed a high proportion of the harvest. A simple deterministic model suggested that the population could remain stationary or grow with current harvest pressure. Thus, the area was not a population sink.
- Volume 10
- Issue
- Pages 139-146
- Publication Date 1 January 1998
- DOI
- File Size 441.27 KB
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