During the six-year period 1967-1972, use of the backcountry in Yellowstone National Park (YNP) more than doubled. From 1973-1977, backcountry recreational use increased by another 53%. As use of YNP's backcountry increased, park managers became concerned over the potential impact high levels of recreational use might have on grizzly bear activity in backcountry areas. Craighead (1980) recommended delineation of critical bear habitat in the Yellowstone ecosystem and restriction of certain types of human activity within these areas. In 1983, the park implemented a Bear Management Area program, which restricts recreational use in areas with seasonal concentrations of grizzly bears. The goals behind these restrictions were to: 1) minimize bear/human interactions that may lead to habituation of bears to people; habituation often results in the bear being removed from the population due to concern for human safety, 2) prevent human-caused displacement of bears from prime food sources, and 3) decrease the risk of bear-caused human injury in areas with high levels of bear activity (National Park Service, 1982).
1. Minimize bear/human interactions that may lead to habituation of bears to people.
Repeated exposure to and interactions with humans may lead to habituation of bears to people. Habituated bears are often perceived as threats to human safety and removed from the population. When a bear is habituated to humans, people are more likely to inadvertently approach within its "individual distance" and be charged (Jope 1983). Habituation also increases the chances of bears becoming conditioned to human foods or garbage. Habituation combined with food conditioning has been associated with a large number of bear-caused human injuries (Herrero 1985). Bear Management Areas promote the type of bear behavior tolerated by people; wary bears that avoid human activities. By reducing bear/human interactions in areas with seasonal concentrations of grizzly bears, Bear Management Area restrictions may reduce the number of habituated bears and the need to remove these bears from the population.
2. Prevent human-caused displacement of bears from prime food sources.
Schleyer (1983) reported that grizzly bears generally avoided areas of human activity and reacted to disturbance by moving elsewhere. Schleyer (1983) also reported that following a disturbance by humans, bears moved a minimum of 3.2 km before stopping and remaining in an area. Human-caused displacement of bears from habitat near recreational developments (Mattson and Henry 1987, Reinhart and Mattson 1990), roads (Green and Mattson 1988), backcountry campsites (Gunther 1990), and recreational trails in nonforested areas (Gunther 1990) has been documented. Human-caused displacement of bears from important foraging areas may result in an overall reduction of habitat effectiveness and carrying capacity. Bear Management Area restrictions help prevent high levels of recreational activity from displacing bears from areas of important bear habitat.
3. Reduce the risk of human injury in areas with a high level of bear activity.
During the last 23 years (1980-2002), bears have injured 32 people within YNP. Grizzly bears and black bears were involved in 25 (78%) and 4 (13%) of the injuries, respectively. The species of bear could not be determined for 3 (9%) of the injuries. Three injuries occurred within a developed area, 2 occurred during a bear management handling accident, and 27 occurred in backcountry areas. Of the people injured while hiking, 57% were hiking off-trail. All (100%) backcountry hiking injuries involved people hiking in groups of less than 3 people. Bear Management Area restrictions reduce the chance of bear/human encounters and the risk of bear-caused human injury in areas with known seasonal concentrations of grizzly bears.
Sixteen Bear Management Areas encompassing 464,638 acres (21% of YNP) have been designated within YNP. This includes 206,100 acres where off-trail travel is prohibited, 161,211 acres closed to human entry on a seasonal basis, 63,867 acres restricted to day-use-only, and 33,460 acres that are closed to human entry for part of the summer, then restricted to day-use-only for the remainder of the summer.
The park service plans to evaluate the success of the Bear Management Area program periodically. As new data becomes available, some areas may be added or deleted from the system. Restrictions for each area will be adjusted to provide maximum potential benefit for the bear, while still providing park visitors a reasonable opportunity to safely enjoy the park's backcountry.
Craighead, J. J. 1980. A proposed delineation of critical grizzly bear habitat in the Yellowstone region. Bear Biol. Assoc. Monogr. Ser. No. 1. 20pp.
Green, G. I., and D. J. Mattson. 1988. Dynamics of ungulate carcass availability and use by bears on the northern winter range: 1987 progress report. Pages 32-50 in R. R. Knight, B. M. Blanchard, and D. J. Mattson. Yellowstone grizzly bear investigations: annual report of the Interagency Grizzly Bear Study Team, 1987. U.S. Dep. Inter., Natl. Park Serv.
Gunther, K. A. 1990. Visitor impact on grizzly bear activity in Pelican Valley, Yellowstone National Park. Int. Conf. Bear Res. and Manage. 8:73-78.
Herrero, S. 1985. Bear attacks - their causes and avoidance. Nick Lyons Books, New York, N.Y. 287pp.
Jope, K. M. 1983. Habituation of grizzly bears to people: a hypothesis. Int. Conf. Bear Res. and Manage. 5:322-327.
Mattson, D. J. and J. Henry. 1987. Spring grizzly bear use of ungulate carcasses in the Firehole River drainage. Pages 63-72 in R. R. Knight, B. M. Blanchard, and D. J. Mattson. Yellowstone grizzly bear investigations: annual report of the Interagency Grizzly Bear Study Team, 1986. U.S. Dep. Inter., Natl. Park Serv.
National Park Service. 1982. Final environmental impact statement, grizzly bear management program. U.S. Dep. Inter. Natl. Park Serv., Yellowstone Natl. Park, Wyo. 202pp.
Reinhart, D. P., and D. J. Mattson 1990. Bear use of cutthroat trout spawning streams in Yellowstone National Park. Int. Conf. Bear Res. and Manage. 8:343-350.
Schleyer, B. O. 1983. Activity patterns of grizzly bears in the Yellowstone ecosystem and their reproductive behavior, predation and the use of carrion. M.S. Thesis. Mont. State Univ., Bozeman. 130pp.
Information Paper No. BMO-5 Kerry A. Gunther
Bear Management Office Wildlife Biologist
Yellowstone National Park March 2003