Volume 2 - No. 2
WATERHOLES FOR WILDLIFE
By Carlock E. Johnson,
"Say Ranger, what do you raise in this country besides dust and cactus?" This question was asked of me one day by a visitor in one of our Southwestern national parks. I explained to him that this country had many cattle and sheep ranches, as well as a huge annual crop of cotton. The conversation finally drifted to wildlife in the region. When I mentioned that we had Mountain sheep, deer, and even a few elk in the park, he was considerably surprised, and even a little dubious.
"If those animals live in this country, they sure must walk a long ways in trying to rustle a square meal," he said.
TThat evening I counted twenty-eight mule deer on a six-mile drive through the park. As I rode along, I thought of the gentleman from Michigan and wished that he could be with me. If those deer couldn't speak for themselves, then he was beyond conviction.
There is much wildlife in our Southwestern national parks and monuments. The wildlife report book in the office is full of reports on deer, coyote, fox, ring-tailed cat, quail, squirrels, song birds, and badger. Many other parks include antelope, elk, bear, and small game among their wildlife census. All of this leads to the subject of game management and its subsequent problems.
In this region one of the most important factors governing wildlife distribution is water. In an area which has an annual rainfall of from ten to twenty inches each year, there is certain to be a scarcity of permanent streams and springs. Man may pipe his water from the mountains. He may sink wells to supply water for his stock. But the wildlife must be dependent upon frequent favors of nature, which are often unreliable. Such rains as do fall here usually are heavy and of short duration, resulting in a heavy surface run-off from the surrounding hills. These rains are often followed by several weeks of hot and dry weather. If some means were available for conserving this surface runoff, it would be a valuable asset to assist in relieving the drain upon the permanent springs in the area. In the case of browsing or grazing animals, the distance which they may forage is directly controlled by the available water supply. The amount of water needed by an animal is in turn governed by factors such as exercise, temperature, and type of food consumed.
Experiments made with deer in the Southwest have shown that where air-dry foods are consumed in the Spring and Fall, the average animal requires one and one-half quarts of water for each 100 pounds of live weight each day. In cases where succulent vegetation is being consumed, this amount of required water is considerably reduced. They also require at least 2.2 pounds of air-dry feed each day for every 100 pounds of live weight. This is the minimum required to maintain weight and vigor.
Lack of accessible water results in a heavy concentration of animals within the vicinity of the available water holes. When this happens, the area soon becomes over grazed with a consequent depletion of the more palatable grasses and shrubs. Yet a few miles away, there may be many acres of excellent forage, which is not being used because there is no water within a traveling radius. Development of a water hole in this area would tend to decrease the population of the over-grazed portion and at the same time would increase the carrying capacity of the total area. It would be possible in many cases to double the wildlife in areas with less damage to the range itself, by a judicious location of these water supplies.
National parks serve as wildlife sanctuaries for several reasons: (1) To give the public a chance to observe this wildlife in its natural habitat. (Many a small boy's eyes have grown as large as saucers while he watched a huge Grizzly bear shambling through the woods!) (2) To preserve species and prevent extinction of those birds and animals, such as the Trumpeter Swan, Bison, Mountain Sheep and Grizzly Bear. (3) To form a nucleus for breeding stock where the wildlife may propagate without interference by man. These offspring in many cases will in turn gradually migrate from the parks and monuments to the surrounding areas, thus furnishing a continuous supply of game for the sportsman of that area. It is, therefore, to his advantage to observe the boundaries of these wildlife refuges. Such cooperation is usually gladly given by sportsmen's organizations.
There are several methods of improving and constructing waterholes. In the case of permanent springs, the water is there. The main problem is to conserve it and obtain the maximum benefit from it. Enlarging the basin of the spring is practical, but in many cases should be discouraged, especially on occasions where blasting would be necessary to enlarge the pool. Disturbance of the water channels by blasting often results in diverting the water back into subterranean passages and causes a subsequent drying up of the spring. Placing a covering over the springs and piping the overflow to a prepared pool is one means of solving the problem. This prevents trampling of the banks and allows the water source to remain pure and free from trash and other defilement, The basins may be of several types. Earthen receptacles made by scooping out shallow pools are the most economical. The chief disadvantage is that considerable water will be lost by soil absorption. This may be partially overcome by laying a concrete flooring in the bottom, or by covering the basin area with a layer of powdered clay or silt mixed with gravel and puddling it. Concrete basins are much more expensive and often will not blend into natural surroundings. Small dams may be erected in the small gullies or canyons, which would serve as storage reservoirs for the overflow, in case excavated basins were not desired. In this way, it is possible to receive the maximum benefits from this meager supply of permanent water. This alone will not solve the problem. There must be some other source of water. Springs and streams are far apart in most of this region. If a plan could be devised to retain some of this lost rainfall, the problem would be partially solved. One of the most practical solutions appears in the form of earthen or stone and earth dams. Dams of the suggested type would conserve a great deal of this water if they were judiciously placed in the canyons and small ravines. Earthen dams are the most simple, economical and practicable type to construct. They may be constructed with materials found near at hand. The only appreciable cost will be that of the labor. CCC projects may be the answer to this. Clay, or clay loam, is an excellent material, if it contains enough gravel to prevent shrinking and cracking when it becomes dry. This may be eliminated by mixing gravel in the clay at the time the dam is made. These dams should be placed in carefully selected sites. There will be some water lost by seepage, evaporation and overflow. Every effort should be made to keep this at a minimum. Any advantages of natural topography should be utilized whenever possible. The water which is retained by the barriers will not form a permanent supply. It will, however, in many cases last several weeks. This will enable the animals to forage these areas for a portion of the year, where in previous times they were unable to do so. As a result, the population in the vicinity of the permanent springs will be decreased and spread more evenly over the entire range, and the carrying capacity is increased proportionately.
When planting is advisable, the following sources of browse for deer may help in deciding the species to use: The three live oaks, (Quercus oblongifolia, Q. Emoryi, and Q. arizonica) Mulberry, (Morus microphylla) and both of the hackberries (Celtis pallida, C. reticulata) are very good forage. Aspen (Populus tremuloides) serves very well. Among the shrubs, Mountain mahogany and both Eriogonum (wrightii) and Hydrangea (Fendlera rupicola) are commonly used. The Eriogonum is especially important as a source of food for large game animals in Arizona. During the succulent stage, portulacas, morning glory (Ipomea, spp.), plantains, pigweeds (Amaranthus spp.) and filaree are very excellent sources of feed. Filaree is especially suited as a winter feed. Mistletoe (Phoradendron macrophyllum) is a good year long feed. These may all be used to advantage to increase the palatability of the range. The whole basis of this plan is to increase the amount of wildlife which the park or monument is capable of supporting, without subsequent damage to the sources of food supply. There is no assumption that nature balance will be destroyed.
|<<< Previous||> Contents <||Next >>>|