Construction Work To Result In Yellowstone Road Closures After Labor Day
Two sections of Yellowstone’s Grand Loop Road will be closed due to construction after the Labor Day holiday weekend. Travel between some points will involve long detours and significantly longer than normal travel times. More »
Food Habits of Grizzly Bears and Black Bears in the Yellowstone Ecoystem
Bears are omnivores that have relatively unspecialized digestive systems similar to those of carnivores. The primary difference is that bears have an elongated digestive tract, an adaptation that allows bears more efficient digestion of vegetation than other carnivores (Herrero 1985). Unlike ruminants, bears do not have a cecum and can only poorly digest the structural components of plants (Mealey 1975). To compensate for inefficient digestion of cellulose, bears maximize the quality of vegetal food items ingested, typically foraging for plants in phenological stages of highest nutrient availability and digestibility (Herrero 1985).
The food habits of grizzly bears in Greater Yellowstone Ecosystem (GYE) have been described in detail by Knight et al. (1984) and Mattson et al. (1991). Overall, army cutworm moths, whitebark pine nuts, ungulates, and cutthroat trout are the highest quality food items available to grizzly bears in the GYE. These foods impart the greatest nutritive value in exchange for the least foraging effort (Craighead et al. 1995). Grizzly bear food habits are influenced by annual and seasonal variation in available foods.
Gunther, K.A., and R.A. Renkin. 1990. Grizzly bear predation on elk calves and other fauna of Yellowstone National Park. Int. Conf. Bear Res. And Manage. 8:329-334.
Herrero, S. 1978. A comparison of some features of the evolution, ecology and behavior of black and grizzly/brown bears. Carnivore 1(1):7-17. _____. 1985. Bear Attacks-Their Causes and Avoidance. Winchester Press, New Century Publishers, Inc., Piscataway, N.J. 287pp.
Knight, R.R., D.J. Mattson, and B.M. Blanchard. 1984. Movements and habitat use of the Yellowstone grizzly bear. U.S. Dep. Inter., Natl. Park Serv., Interagency Grizzly Bear Study Team. Unpubl. Rep. 177pp.
_____, B.M. Blanchard, and D.J. Mattson. 1988. Yellowstone Grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 1987. U.S. Dep. Inter., Natl. Park Serv. 80pp.
Mattson, D.J., and C. Jonkel. 1990. Stone pines and bears. Pages 223-236 in Proceedings-Symposium on Whitebark Pine Ecosystems: Ecology and Management of a High-Mountain Resource, U.S. Dep. Agric., U.S. For. Serv. 386pp.
Mattson, D.J., B.M. Blanchard, and R.R. Knight. 1991. Food habits of Yellowstone grizzly bears, 1977-87. Can. J. Zool. 69:1619-1629.
Mattson, D.J., B.M. Blanchard, and R.R. Knight. 1992. Yellowstone grizzly bear mortality, human habituation, and whitebark pine seed crops. J. Wildl. Manage. 56:432-442.
Mattson, D.J. 1997. Use of Ungulates by Yellowstone grizzly bears Ursus arctos. Biol. Conserv. 81:161-177.
Mealay, S.P. 1975. The natural food habits of free-ranging grizzly bears in Yellowstone National Park, 1973-1974. M.S. Thesis, Montana State Univ., Bozeman. 158pp.
Reinhart, D.P. 1990. Grizzly bear habitat use on cutthroat trout spawning streams in tributaries of Yellowstone Lake. M.S. Thesis, Montana State Univ., Bozeman. 128pp.
Did You Know?
Some groups of Shoshone Indians, who adapted to a mountain existence, chose not to acquire the horse. These included the Sheep Eaters, or Tukudika, who used dogs to transport food, hides, and other provisions. The Sheep Eaters lived in many locations in Yellowstone.