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Fauna Series No. 1
Methods
Fauna of the National Parks
of the United States
PROBLEMS OF HISTORICAL ORIGIN
ABNORMAL ANIMAL POPULATIONS DUE
TO EARLIER REMOVAL OF NATURAL CONTROLS (4)
Problems of this type that trace back to pre-park conditions are usually found to have been by-products of the stock-raising industry. Predatory animals, which normally controlled the undue increase of the wild ungulates, were eliminated to protect stock on the ranges and incidentally to provide more game for hunting. So long as they were open areas, the gun more than took the place of the predators, but the situation was reversed when they became parks. The large game increased without check until it further destroyed ranges which had already been impoverished by sheep and cattle. Worse than that, this unusual protection not only permitted the healthy animals to survive but also failed to take off the diseased and unfit, leaving them to reproduce and deteriorate the breeding stock. The local situation produced by an abnormal density of impoverished ungulates in conjunction with forage of greatly subnormal density and quality is like a bad fire hazard. All it requires is a bad season to precipitate a calamity. Only in one case the critical factor is a dry summer, in the other it is a snowy winter. In general, the solution of problems of this type is to be sought in the restoration of the natural control factor in environment. Yet in many instances this may take place so slowly that artificial control may have to be substituted as a temporary measure. Shooting for sport is unsatisfactory because it is selective of the finest specimens instead of the poor ones which, by rights, should be removed first.
Mule deer on north rim of the Grand Canyon. – This is a park question but, in its larger aspect, it is the Kaibab deer problem, which is so well known that it only needs to be mentioned here to serve as an excellent illustration.
Mule deer in Yosemite Valley. – Because the mountain lion was gone and other conditions altered, deer increased until the once famous wild-flower show on the floor of Yosemite Valley became a thing of memory, and even the brush was threatened with destruction. Deer were so common and so goat-like – having no need to be alert, and hence losing their charming wild behavior – that their interest to the visitor was greatly lessened. Crippled and diseased individuals which do not last long under natural conditions dragged around and added to the ugliness of the picture.
FIGURE 15. – Deer are particularly fond of the
flower beds of Evening Primrose (Oenothera hookeri).
They did not
overlook one in these three clumps, though the plants grew inside a
supposedly deer-proof fence.
Photograph taken July 20, 1929, in Yosemite
Valley. Wild Life Survey No. 186
The first protective move made was to fence a few acres around the Ahwahnee grounds to preserve the plant life. This was not really compatible with national-park ideals.
Physically incapacitated deer were dispatched, and this helped one aspect of the problem.
A third measure was tried with success. Deer had been practically exterminated from the Tuolumne watershed in a successful campaign to stamp out hoof-and-mouth disease in 1924. Two purposes could be accomplished by transferring deer from Yosemite Valley in the Merced watershed to the Tuolumne drainage, and this has been done for several seasons, the method being to entice the animals into a corral, then load them on trucks for immediate release at the destination. The transplanted animals have not tended to drift hack, so that the deer population of the valley is now more nearly within bounds.
Because a return of the mountain lion to the area is unlikely, due to the fact that all lions ranging in the park can be, and are, taken outside the boundaries, transplanting of deer may have to be more than a temporary measure of relief. However, throughout the park system the Service's policy of strict protection for predatory species is doing much to avert similar problems.
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Last Modified: Tues,
Feb 1 2000 07:08:48 pm PDT
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