OVERVIEW

HISTORY

ACTORS

MAPS

DIMENSIONS:

ecosystem

wildlife

economic

policy

recreation/aesthetic

social

STUDY TEAM

REFERENCES

Grizzly Bears and thw Endangered Species Act

Due to extensive habitat loss and reductions in density, grizzly bears in the contiguous United States have been listed as a threatened species under the ESA since 1975.  This means that the bears run the risk of becoming endangered.  Currently, much debate exists concerning the continued listing of the bears.  Some feel that the population is stable, yet others feel that the bears are not yet free of extinction risks.  Despite this conflict, the majority of scientists who are familure with grizzly bears agree that the population is currently not at secure densities (Craighead 1999). In the contiguous United States, the Yellowstone population of bears is one of the largest.  This alone, however, does not ensure continued persistence.  Due to the fact that the Yellowstone ecosystem is a habitat island, there are many reasons to warrant concern.  One such reason is genetically based, while another is due to mortality associated with use of the park.  Under the ESA, threatened and endangered species are to be managed in a manner that will promote the species biological stability.  In doing this, the ESA explicitly states as its purpose “to provide a means whereby the ecosystems upon which endangered species and threatened species depend may be conserved” (Sect. 2(b)).  In order to try and combat the existing extinction threats, the US Fish and Wildlife Service has issued a recovery plan for the species that encompasses the entire lower 48.

In the Yellowstone ecosystem, there is ample reason to believe that this is not occurring.  Development and land use around the park are continuing to increase, reducing the habitat available to grizzly as a result.  Since large carnivores have large area requirements, large expanses of undisturbed habitat need to be available to support a viable population.  In the Rocky Mountains, the annual home range for a single grizzly bear is nearly 900 km² (Blanchard & Knight, 1991).  Being so, the amount of undisturbed and connected habitat needs to be much more that what is currently offered, and continued encroachment will only result in further reduction of the population.  Mealy (1986) points out that the definition and designation of prioritized management areas within the grizzly bear recovery zone are strikingly compatible with preexisting human activities and land uses.  He even goes so far as to say that the designations have failed to reflect the intent of Congress (US Congress 1977) when it called for the designation of critical habitat.  Mattson and Reid (1991) state that land management for the bears has not been based upon any substantive biological evaluation of the habitat.  Both resource extraction and continued development outside of the park put the bears at risk, due largely to the development of associated roads and the possibility of habituation.

Interesting links:

History, Administration, and Recovery as they pertain to the ESA: http://endangered.fws.gov/esasum.html

The ESA as it pertains to Wolves in Yellowstone

A literature compilation on grizzly conflicts with resource-extraction:

http://www.canuck.com/off-road/RelatedLit2.html

Links on the delisting debate:

http://www.wyomingoutdoorcouncil.org/frontline/spring2000/grizzdelisting.html

http://forests.org/archive/america/badblist.htm

http://www.jimmorris.com/alerts2000/alertsnext/Ygrizzlyalert.html

http://www.bitterroot.com/grizzly/bears77n.htm