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Yosemite Nature Notes 46(2) (1977)

black bear
[click to enlarge]

Managing the Resources

by Rich Tobin

What do the Bighorn sheep, gray wolf, grizzly bear and golden beaver have in common? Each of these animals has made the Yosemite region its home.

This, and volumes more of information is currently finding its way into the office of Resources Management for inclusion in the new General Management Plan for Yosemite National Park.

The objectives for the future resources management of Yosemite include: (1) Restore and maintain natural terrestrial, aquatic, and atmospheric ecosystems so they may operate essentially unimpaired, (2) Conduct continuing research to gather and analyze information necessary for managing natural resources, (3) Restore altered ecosystems as nearly as possible to conditions they would be in today had natural ecological processes not been disturbed, (4) Protect threatened and endangered plant and animal species and reintroduce, where practical, those eliminated from the natural ecosystems, (5) Identify and perpetuate all natural processes in Park ecosystems, and (6) Permit only those types and levels of use or development that do not significantly impair Park natural resources.

The Bighorn sheep, gray wolf, grizzly bear and golden beaver have been studied as a result of this plan, and guidelines for their future management have been proposed. Although these four animals have made Yosemite their home, this is where their similarities end.

Although the California Bighorn Sheep (Ovis canadensis californiana) was once thought to be extinct in Yosemite after 1914, small, remnant populations of Bighorn have since been sighted in and near Yosemite. The Park Service is now considering a program aimed at restoring the Bighorn to a more natural population size.

Wildlife scientists have determined that the Park has an abundance of high quality summer and fall habitat, and suitable winter range exists on the eastern slopes of the Sierra. Any restoration efforts will focus first upon management practices which may increase the size of a remnant population already in the Park. If this effort is unsuccessful, an attempt will be made to reintroduce the Bighorn from another population source. If this occurs, Bighorn will be selected which are as genetically and eco-typically similar as possible to the Bighorn which currently inhabit the Yosemite region.

The grizzly bear (Ursus arctos horribilis) and the gray wolf (Canis lupus) once roamed freely across the Yosemite region. However, the reduction in suitable habitat by urbanization, agriculture, and hunting pressure soon led to their extinction from the Sierra Nevada in the early 1920’s.

Although the Resource Management Plan calls for the restoration of natural animal populations to Yosemite, the Park Service has no plans at this time to initiate such a program for the grizzly bear or grey wolf. This is based upon the fact that each of these animals requires a larger year around habitat than the Yosemite region can provide. In the pursuit of suitable habitat, the grizzly bear and the grey wolf probably would venture into surrounding lands, where conflict between grazing livestock, recreational activities and hunting would prevent the survival of a viable population. In addition, due to intensive visitor use within the Park, visitor safety would be jeopardized beyond acceptable levels.

The golden beaver (Castor canadensis subauratus) is another animal which lives in the Yosemite area. But, unlike the previous animals, the golden beaver was not native to the Sierra Nevada above the lowest foothills. The California Department of Fish and Game introduced golden beaver populations adjacent to the Park in the early’) 1940’s. Since then, the beaver has moved upstream into the Park in a few limited areas.

In keeping with the objectives of the resource management plan in the restoration and maintenance of natural ecosystems, beaver populations found within the Park will be removed and future checks made to prevent reoccupation by downstream populations.

Yosemite National Park is one of the last remaining areas in the United States where nature and natural processes continue unimpaired. The new General Management Plan, of which the Resources Management Plan is an essential component, hopes to further the purpose and promise of the National Parks.

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Online Library: Title Author California Geology History Indians Muir Mountaineering Nature Management