Probable Grizzly Bear Predation on an American Black Bear in Yellowstone National Park
Gunther KA, Biel MJ, Anderson N, Waits L. 2002. Probable Grizzly Bear Predation on an American Black Bear in Yellowstone National Park. Ursus. 13:372-374
Both grizzly bears (Ursus arctos) and American black bears (U. americanus) live in Yellowstone National Park (YNP), which is located primarily in Wyoming, USA. In areas where grizzly bears and black bears are sympatric, temporal isolation and behavioral differences likely reduce direct competition between the species (Aune 1994). In the Greater Yellowstone Ecosystem (GYE), grizzly bears are generally most active during nocturnal and crepuscular times (Schleyer 1983, Holm et al. 1999), whereas black bears are mostly diurnal (Barnes and Bray 1967, Holm et al. 1999). Grizzly bears evolved to exploit nonforested habitats, whereas black bears are primarily forest adapted (Herrero 1978). Grizzlies are also generally larger than black bears and much more aggressive in defending themselves and their offspring from conspecifics and other predators (Herrero 1978), whereas black bears typically escape predators by running into forest cover or climbing trees (Herrero 1985). Due to their larger body size, grizzly bears have a competitive advantage over black bears in large non-forested areas (Herrero 1977). Although displacement of black bears by grizzly bears from high quality habitat has been documented (Shaffer 1971, Kendall 1984, Aune 1994), interspecific killing of black bears by grizzly bears has only occasionally been reported (Arnold 1930, Jonkel and Cowan 1971, Murie 1981, Ross et al. 1988, Mattson et al. 1992).
- Type
- Journal Article
- Authors
- Gunther, Kerry; Biel, Mark; Anderson, Neil; Waits, Lisette
- Units
- YELL
- Keywords
- American black bear, Grizzly Bear, interspecific killing, Predation, Yellowstone National Park