Food and habitat used by grizzly bears (Ursus arctos) in the Front Ranges of Banff National Park were studied during 1976-80 using fecal analysis, feeding site examination, direct observation, and radio-tracking. Important foods included pink hedysarum (Hedysarum alpinum) roots, yellow hedysarum (H. sulphurescens) roots, bearberries (Arctostaphylos uva-ursi), graminoids, horsetails (Equisetum arvense), buffaloberries (Shepherdia canadensis), and Vaccinium spp. fruits. Most foods were eaten in dry meadows, shrubfields, or open forest. Horsetails were the only notable exception; many feeding sites occurred in mature forest. The alpine zone was unimportant as feeding habitat. Seasonal changes in diet and habitat use appeared to be related to plant phenology with bears eating plant parts which seemed to be at nutritious development stages. Hedysarum roots, the bears' major food, had significantly less crude protein and more fiber when plants were flowering than when they were in pre-leaf. Related to this, digging by bears was minimal during the mid-summer flowering period. Seasonal habitat use also appeared to be influenced by hedysarum phenology. As the spring digging season progressed, hedysarum diggings occurred more on north-facing slopes and at higher elevations, where phenology was retarded. Later-season root digging was inversely related to buffaloberry abundance: the volume of roots in feces during August-October was greater in 1976 and 1978, 2 years when buffaloberry abundance was significantly lower than in 1977 or 1979. We concluded that buffaloberries, known to be high in soluble carbohydrate, were preferred over hedysarum roots. During summer, grizzly bears ate horsetails in sites where the plants were in immature, nutritious development stages. The elevation of horsetail feeding sites was significantly higher in late July-August than in early July. Grizzly bears thus ate food high in soluble nutrients and low in fiber by making seasonal changes in both the food and habitat they selected.
- Volume 7
- Issue
- Pages 199-213
- Publication Date 1 January 1987
- DOI 10.2307/3872626
- File Size 996.50 KB
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