Fauna of the National Parks
of the United States
ANALYSIS OF THE MAJOR TYPES OF WILD-LIFE PROBLEMS THEIR CAUSES AND TREATMENT
When a roster of typical wild-life problems from the whole national park system was assembled, a very wide range of maladjustments was revealed. A systematic analysis was made to trace each problem back to the basic disturbance which brought it about. For if any common denominators could be found, that knowledge would be a key to devising a betterment plan. Early in the work it became apparent that the fundamental causes were relatively few. If a number of problems could be traced to a common origin, more rapid and orderly progress in wild-life administration would be possible than if each problem were dealt with as an isolated instance.
From this analytical study the conclusion was reached that present complications in the status and environmental relations of park animals have come from these three general sources:
1. Adverse early influences The present unsatisfactory status of an animal may be the result of a destructive force which itself is no longer active. These are problems caused by early influences. It is convenient to think of them as the problems of historical origin. Problems of this class fall into two groups, according to whether the influence was one which destroyed these fauna directly or one which operated indirectly by altering some part of the environment upon which the fauna depends.
2. Failure of parks as independent biological units. A park is an artificial unit, not an independent biological unit with natural boundaries (unless it happens to be an island). The boundaries, as drawn, frequently fail to include terrain which is vital to the park animals during some part of their annual cycles. The smaller the total area of a park the more its animal life may be endangered by external influences. Problems caused by the failure of parks as biological entities have to do with their geographical aspects, such as size and boundary location. It is easy to think of them as problems of geographical origin. They logically fall into two groups, according to whether they have come from failure to include all habitats required by park animals or from external influences which do not find the boundaries a natural barrier.
3. Conflict between man and animal in the park. Troublesome situations inevitably arise when men and certain animals with conflicting interests try to occupy the same places at the same time. These complications come in spite of the human ideal that the wild life of the parks shall remain in a primitive state unmodified by civilization. Disturbances of this origin constitute the third class, the problems caused by conflict between man and animal through joint occupancy of the park areas. For brevity's sake they may be designated as problems of competitive origin. And once more it is profitable to make two divisions, this time according to whether problems are due to injury of man by the animals or due to man's occupation of the area affecting the fauna adversely.
These three basic causes are responsible for the multitude of problems which must be solved with at least fair success if the faunal resource of the national parks is to be conserved.
The administrative measures invoked in every instance must he analysis gaged by accurate analysis of the causative factors which bred the problem. This is important. It is the key to proper practice in the program of wild-life administration upon which the parks have unavoidably embarked. In the end the Service either will be praised for intelligently conserving the last fragments of primitive America or condemned for failure to hold to the real purpose by shooting clear over the mark and practicing game farming instead.
The rigors of civilization have injured the fauna of the country as a whole. In a national park the damage can not be undone by policing a boundary line. This is protection and it is necessary, but it does not correct conditions already operative within the park. These must be sought out where they are doing damage and dealt with there. This is management, and the danger that it may be overdone is not sufficient reason for doing nothing.
Recognition that there are wild-life problems is admission that unnatural, man-made conditions exist. Therefore, there can be no logical objection to further interference by man to correct those conditions and restore the natural state. But due care must be taken that management does not create an even more artificial condition in place of the one it would correct.
If each problem is carefully analyzed as to its cause, and the type of management appropriate to problems caused in that way is then applied, management will not destroy its own purpose. Admittedly, the tool is a dangerously sharp one to use in a national park. That is why it must be handled within skill in biological engineering, a science which itself is in its infancy.
It is important in every case that the hand of interference should not be exercised beyond the point that is necessary to do the work. In some instances if the situation responsible for the maladjustment of a species can be corrected, that bird ear mammal will come back to its former status. Failing this, additional measures may be temporarily necessary to help it recuperate its strength. But where the basic disturbance can not be eliminated, management to counteract the evil effects may have to be instituted to continue so long as the harmful influence continues.
All of the problems which the survey has encountered to date are believed to be of historical, geographical, or competitive origin. The following outline lists major types of problems in each of these causative groups.
TYPE PROBLEMS LISTED BY CAUSE
The scope of this report prevents discussing at length every problem encountered. Consequently the plan has been adopted of discussing the essential elements of each type of problem listed above and illustrating each with one or more examples treated in detail. These examples will serve as type problems to which others resulting from similar causes can be referred for comparison and study. Then in later sections dealing with the vertebrate life of each park as a unit, only those problems on which the survey has accumulated special data have been accorded more than outline treatment.
Where it seemed that more than one of the major causes entered into a certain problem, close inspection revealed that one of them was dominant in producing the present situation. These have been handled by allocation under their dominant cause.
The type problems given in the next three sections are arranged in accordance with the foregoing outline. They have been numbered to conform with the Arabic numerals in the outline merely to facilitate reference and to further emphasize the relation of problem to cause.