BIO 203

Habitat and Geography

    Grizzly bears live in a wide variety of habitats. They can be found in forests, woodlands, prairies, mountains, meadows, desert, grassland, and arctic tundra. They occupy the continents of Asia, Europe, and North America (Hedstrom, 1993).
    In North America, grizzly bears are currently found in Canada, Alaska, and westward from Montana to Washington. They were previously found all across the continent, from Mexico to Alaska (Grizzly, 2013). However, due to human industrialization, their habitats in the southern portion of North America have been destroyed (Horejsi, 2008). Currently, less than 2% of the original grizzly bear habitat remains (Hedstrom, 1993).

U.S. Geological Survey

     The number one threat to grizzly bears is habitat loss. The huge loss of habitat is one of the causes that led to grizzly bears being listed as an endangered species (Payton, 2001). Because grizzly bears require a large amount of food to survive, they need a large amount of land to supply their food source (Hedstrom, 1993). Grizzly Bears are very solitary animals and they need large, open lands in order to live apart from other bears and human influence (National, 2011). With the development of roads for timber and mining and the expansion of industry as well as residential expansion, humans are intruding on grizzly bear habitats (Bass, 2002). Grizzly bears also need space from humans for their own protection. Hunting has led to the vast majority of grizzly bear mortalities (Horejsi, 2008).
     Another effect of human industrialization of grizzly habitat is the close contact bears now have with humans. Due to the high demand for nutrients and caloric intake in order to store fat for hibernation, grizzly bears are in a non-stop search for food (Grizzly, 2013). Sometimes this may mean entering human settlements when the bears cannot find a source of food in what is left of their habitat. Their search for food often finds them digging in garbage cans or feasting on livestock. It is believed that because of the close living quarters, grizzly bears are becoming too comfortable around humans (Atkinson, 2007). Instead of avoiding human areas, bears are seeking them out in hopes of a free meal. This can be dangerous to both the bears and humans.
     During their hibernation period in the winter months, grizzly bears live in dens. They commonly dig these dens under tree roots or find a resting place inside a cave. They usually choose dens in high altitudes that will be covered in snow during the winter as this creates an extra layer of insulation (Brown Bear, n.d.).


Form and Function