Changes in land use are currently accelerating development pressures in the Central Canadian Rocky Mountains. Given the existing and proposed human influences in the region, cumulative effects are a major issue, especially for carnivores. I quantitatively and qualitatively assess the effects of human actions on grizzly bears (Ursus arctos horribilis) and their habitat. Since 1985, a cumulative effects model (CEM) for grizzly bears has evolved into the consolidated form used by the U.S. Department of Agriculture (USDA) Forest Service. The habitat effectiveness model presented in this paper follows the USDA Forest Service CEM with minor changes to allow our data to conform to the process. I analyzed a study area of approximately 9,300 km2, and results indicate that much of the 3 National Parks are only moderately productive habitat, excluding human influences. Adding the effects of humans, the modelled ability of the landscape to support bears is significantly reduced. The model suggests widespread habitat alienation in what is supposed to be core refugia for grizzly bears, questioning the ability of the landscape to support a viable population. This situation we find ourselves in is a particularly difficult one, given that incremental recreational development has never been considered a threat to the protected status of Canadian national parks. In the Canadian Rockies, mountain national parks function as de facto core refugia for grizzly bears. With continued erosion of grizzly bear habitat in what is supposed to be core refugia, time is clearly not on the park manager's side. Swift, and in some cases, drastic management action is needed if we are to stem grizzly bear extinction within the ecosystem.
- Volume 10
- Issue
- Pages 235-241
- Publication Date 1 January 1998
- DOI
- File Size 580.91 KB
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