FORESTS AS A WILDLIFE HABITAT

LLOYD W. SWIFT.

The amount and quality of food, the difficulty in getting it, and the assurance that there will be some next winter determine many of the activities and habits of man and beast how hard one works, where one lives, how well one is nourished. So, too, with shelter, weather, and moisture (which we sum up in the word habitat), which determine, for instance, whether a deer can live in a desert, whether a variety of corn can grow in Alabama, whether one can transplant a wild flower from its native woods to a garden. Almost any change in habitat can change the number and kind of living things in it. Wild things, wild mammals and birds, reflect more exactly than tamer creatures the conditions of their habitat, which nature and man are constantly changing.

The minute they put foot on these shores the first settlers from Europe started changing the habitat of wildlife. They (and their descendants) pursued and killed the birds and animals for food, clothing, or recreation, or because the wildlife conflicted with crops or livestock; they also caused far-reaching changes in habitat by clearing land, logging, and fires.

Originally in the eastern half of the United States, much of the cover was of hardwoods, to which many kinds of wildlife were adapted and in which the nuts or mast from oaks, hickories, chestnuts, walnuts, and beech and the fruits and berries of gum, grape, dogwood, persimmon, and other trees. vines, and shrubs gave ample food. The hardwood forests also provided small tree dens for squirrels, larger ones for raccoons, and trunk dens for big animals, like the black bear. Less favorable a habitat were the original coniferous forests in the East; the pine, hemlock, and spruce stands furnished a smaller variety and quantity of food, and dens were less frequent and satisfactory. Therefore, the animals of the conifer forests were likely to be more specialized, or at least closely associated with the more restricted food and the cover conditions found in the conifer forests.

Where the two types overlapped and made a mixture of hardwoods and conifers. or where the local climate was modified by protected and exposed sites, such as in the mountains, the variety of food and cover undoubtedly favored a greater variety of wildlife, but not necessarily a greater quantity than in the food-rich hardwood forests.

In the West, the forests were largely conifers junipers commonly occupied the low places in the Rocky Mountains and adjacent areas, spruces the higher elevations, and pines in between. There the stands were often bisected by fingers of open grassland, meadows, or brush fields; the native forest had extensive borders or edges, a condition that is generally favorable to wildlife; the volume of nuts and fruit was not ordinarily high in the forest areas, but the forage conditions frequently favored browsing and grazing animals.

The forests on the Pacific coast, west of the crest of the Cascade Mountains, were of a closed conifer stand, which, under the influence of favorable moisture and growing conditions, were characteristically dense and tall. The ground was commonly in permanent shade. Wildlife was more restricted than in an open forest or a hardwood stand, but those forests were outstanding in the character of the fish life in the streams and the rivers, which were spawning grounds of the sea-run salmon and trout.

Thus, although the hardwood forest undoubtedly was the home of a greater variety and quantity of wildlife, all forest areas were likely to support some deer, bear, squirrels, beaver, and wolves. Some variety of grouse was native to all areas, except the forests of the Coastal Plain in the South and Southeast. Elk ranged in nearly all regions, except the South. Beaver were present in nearly all forests. Turkey were distributed from New England to Colorado and Arizona. The bighorn sheep lived in the mountains of the Western States, mountain goat in the country north of the Columbia and Snake Rivers, and moose in the north Woods and northern Rocky Mountains.

Beaver were most abundant where suitable water was associated with favored food species, such as aspen, cottonwood, and the willow. The turkey range appeared to be adjusted to the availability of mast acorns, chestnuts, and pine nuts, particularly in winter. Different species of grouse had developed rather specialized feeding habits, and could winter on the buds of conifers or hardwoods where it lived.

Similar relationships could be cited for other species, and the food preferences of some predators, such as the cougar or puma for deer, could be mentioned. Those examples are sufficient, however, to illustrate the point that the animals were distributed according to a habitat pattern, in which their basic needs for food and cover were met. In that respect, the character of the forest was paramount in determining the kind of wildlife that would fit in and how abundant it might become.

SETTLEMENT AND HUNTING soon changed the situation. In colonial and pioneer communities, game laws were commonly thought unnecessary; the few that were passed were liberal and seldom enforced. The feeling was general that the people who settled an area or owned land were entitled to unrestricted use of the wildlife resources, a philosophy that prevailed in some sections of the country until a few years ago and that was particularly characteristic of forest communities. Further, until the present generation, many State fish and game departments were so inadequately financed that they could not maintain an adequate warden force, let alone investigate the status of the wildlife resource.

Under those circumstances, game and fur animals suffered. A few species Were exterminated. Others disappeared from large sections of their native range, and only recently were reestablished through programs of restocking. In the East, the white-tailed deer had mostly disappeared by 1910; the elk were all gone by 1870. In many parts of the West, elk were killed out. One species, the Merriam elk of the Southwest, had been exterminated by 1898. Beaver were so persistently trapped that they were exterminated from large areas of the Eastern States, and became scarce in the Lake States and the Rocky Mountains. The once abundant passenger pigeon disappeared entirely.

Forest animals that came into conflict with man often became the object of eradication campaigns, which included bounties and professional hunters. They exterminated the gray timber wolf from virtually all its range except a small part of the Lake States, yet originally the timber wolf and subspecies, such as the buffalo wolf, occupied nearly all of the territory now in the United States, except California. The cougar, or mountain lion, once was associated with all forest regions; now it is found in the rougher sections of the West, but in the East is limited to a few individuals in Florida. The grizzly bear, once a respected animal of the western range and forest country, now is confined to the wilderness sections only of Montana, Idaho, and Wyoming. The last known California grizzly, the Golden Bear of the California State flag, was killed in 1922.

THE CLEARING OF FORESTS for agriculture and the widespread cutting and burning of the remaining wooded areas profoundly affected the wildlife habitat. One important change was the increase in the borders and edges in the remaining forest and woodland areas; another was the tremendous increase in the herbaceous and shrubby cover, which favored browsing and edge animals, such as deer, bobwhites, rabbits, and grouse.

The relation of forest changes to deer management in the East and the Lake States is of particular interest. The virgin forests were not particularly well suited to deer, because openings and browse areas were limited. But after the forests were opened up by lumbermen, and further changed by fires, the browse supply became extensive. At about the same time, some States started to protect and restore the white-tailed deer. Through restocking where needed and the adoption of laws favorable to building up the herds, the deer were especially encouraged just when the food supply became most abundant.

The deer thrived beyond expectations. Instead of a few hundred or a few thousand deer, States like Pennsylvania and Michigan soon had several hundred thousand. All seemed for the best, until it was realized that the deer had exceeded the food supply. The browse shortage was intensified by the fact that under improved fire protection the forests were recapturing the land. The stems and twigs, which had been good browse for deer, had developed into pole-sized stands of second-growth forests. As the trees grew beyond the reach of the deer, they formed a closed canopy and shaded out the shrubs, vines, and herbs.

The deer and elk have made marked increases also in the western forests, but the situation has been somewhat different. There was the same public support for herd protection, but logging and fires had affected but a small proportion of the forest area. The western forests, with certain exceptions, however, were grazed by cattle and sheep. Therefore, when big-game species increased, they often did so on land that was already being grazed too heavily by domestic livestock. The situation created many problems on public and private land, and much good livestock and game range has been seriously overused. As in the East, the reduced food supply has brought about starvation of big game in localities where the hunters have not harvested the surplus.

Although the cut-over and burned forest favored deer, elk, and grouse, it was not good for species that required stands of old growth; the tree squirrels found less food and fewer dens; the marten and fisher could not exist in the new environment; the turkey also found the young, open forests unsatisfactory because they were deficient in mast.

The change in the forest cover also changed the stream conditions and fish life. Under the virgin-forest conditions, the streams were normally in a stabilized condition. And the forest cover checked the runoff; streams ran clear; flows were normal; channels tended to be stable, and water, temperatures fluctuated only a little. But when watersheds were seriously disturbed by logging, fire, or grazing, the streams were subjected to flood conditions and disturbance of channels; the aquatic habitat suffered; insect life was smothered by silt or injured by abrasion; gravel spawning beds silted up; food-producing ability was lowered; and summer temperature was raised. In cases of extreme change, good trout waters became nearly barren of such fish.

When the general public realized, a generation or more ago, that the wildlife resource was so seriously impaired, there was support for wildlife protection and restoration. The first reaction was to restrict the take, often to the point of yearlong closed seasons. In extreme cases, such as the bighorn sheep, the ptarmigan, and certain other species, some States have had closed seasons for 20 years or more. Other methods of restricting the take as a measure to protect the breeding stock included refuges, short seasons, small bag limits, and restrictions on sex and age. Such forest big game as deer and elk were subjected to the "buck laws," which designated male animals with certain antler developments as legal game, providing full protection to females. Refuges became popular in the 1920's; vast areas of forest lands were included in the State game refuges, and smaller areas in Federal refuges.