Vigilance Required to Control Wildlife Harvest

When human society interacts with wildlife, don't bet on the wildlife. Human activities throughout history have subjected wildlife to great stress, caused both by the harvesting of commercially valuable wildlife species and by the destruction of habitat in the course of economic development. Today the stress is more intense than ever, not only in the industrialized countries but also, and especially, in Third World nations.

The potential for human misuse of wildlife resources is very great for two major reasons. The first is the wide range of interests making decisions that affect the fate of wildlife (for example, those who clear the land to plant crops or to build dams for flood control or irrigation): they rarely are the direct beneficiaries of actions that protect wildlife species, and by the same token they rarely suffer as a result of actions that harm these resources, so there is no major incentive or disincentive for taking wildlife into account.

Second, potential misuse arises from what is called "the commons" problem. Because animals do not respect property, private ownership of wildlife resources is generally impossible. Wildlife is a common property resource, and institutional arrangements that substitute for private property ownership are needed to prevent harvesters, including sportsmen and commercial hunters, fishermen, and trappers, from regarding the resource as a free good. Without such protection of the resource, overuse may lead to its degradation or ruin.

In the view of many experts, the current outlook for the future of large numbers of wildlife species throughout the world is fairly bleak. The wholesale extinction of entire plant and animal communities is said to be likely by the end of this century. Some scientists believe that more than a thousand species are disappearing worldwide each year, mostly in the humid tropics. (The number that is estimated to be disappearing is based on calculated rates of destruction of tropical forests known to be rich in such species.) Most of these species have not even been discovered, primarily because of the inaccessibility of their habitats.

U.S. outlook

By contrast, the outlook for wildlife resources in the United States is mixed. On the negative side, many species without recognized commercial value are in decline. More than 200 domestic species of plants and animals are included on the list of endangered species compiled by the U.S. Fish and Wildlife Service. In addition, certain types of habitat are apparently disappearing—wetlands, for instance, at the rate of 300,000 to 600,000 acres per year. Total wetland acreage is estimated to have declined from 125 million to 75 million acres since 1850, according to a 1982 report of the National Academy of Sciences, Impacts of Emerging Trends on Fish and Wildlife Habitat.

These negative trends can be more clearly understood from a historical perspective. Until the turn of the century, exploitation of wildlife resources in North America was limited neither by private property rights nor by government intervention. Because private property rights did not exist, individual hunters had no incentive to husband the resource: any animal not taken would very likely be taken by someone else. In addition, the few hunting regulations in existence were virtually unenforced. As a result, wild stocks of many species were decimated.

At the same time, wildlife habitat was being destroyed as settlement imposed great changes on the continent's land and waters. The land was valued for its potential to produce commercial products rather than for the natural habitat that nurtured noncommercial "products"—namely, wildlife. Even if an individual landowner preserved the habitat, there was no guarantee that the "products" would not wander away onto someone else's land. Since wildlife could not compete in the marketplace, the destruction of habitat could not be checked by market forces, and by 1900 few authorities on the subject held out much hope for the survival of any of the larger forms of wildlife such as deer, elk, and bear in the United States past 1930.

Surprise recovery

Despite this gloomy prediction, however, a number of important game and other species in the United States have made remarkable comebacks since the turn of the century. The beaver, once eliminated from all of the eastern states except Maine and common only in parts of the Rockies and the Pacific Northwest, is now common in all states but Hawaii. The population of white-tailed deer has increased from about 350,000 in a few states in 1895 to 12 million in forty-eight states today.

There have also been dramatic increases over the past hundred years or so in the populations of pronghorn antelope (from 13,000 to 500,000), bison (from 800 to 6,000), and elk (from 41,000 to 1 million). The wild turkey, which inhabited only a few southern states in 1930, is now found in forty-three states. Several egret and heron species nearly extinct in 1910 are now common throughout the United States, according to the Wildlife Management Institute. Northern fur seals have increased from 215,000 in 1911 to 1.5 million today, and the sea otter is again establishing itself in its native habitat off the Pacific coast from Washington to northern California. Migratory bird populations have also recovered from the low levels to which they had dropped early in this century. The species that have been restored include the trumpeter swan, the wood duck, and, most spectacularly, the whooping crane, up from a low of 14 cranes in 1953 to well over 100 cranes today.

In part, this turnabout in wildlife populations resulted from the incidental reforestation that took place in the early twentieth century following the abandonment of farms on the eastern seaboard that could not compete with western agriculture. But probably more important has been the success of state and federal actions taken to protect valued fish and wildlife species, actions whose origins can be traced back more than a century. By 1880 every state had taken the first steps to restrict access to wildlife resources by such measures as bag limits (on the number of individuals or the volume that a sportsman could take within a certain time), limited hunting and trapping seasons, and restrictions on the type of individuals that could be taken (females or the young often being proscribed).

These regulations were difficult to enforce, however, until passage of the Lacey Act of 1900, which made it a federal crime to cross state lines with wildlife killed in violation of state law. The Lacey Act also made any wildlife imported into a state subject to that state's laws, as if it had been killed there, whether or not it had been taken lawfully. The federal government was also active in setting aside wildlife habitat. The National Wildlife Refuge System, established in 1903, now takes in more than 80 million acres—about half in the continental United States and half in Alaska.

In Canada, the decrease in wildlife populations began somewhat later than in the United States, but the story follows the same pattern of overharvesting and decline, with recovery resulting in large part from governmental measures instituted to halt the declines. The history of wildlife protection in North America thus demonstrates not only that wildlife management can be effective, but that even badly damaged resources can recover when overexploitation by harvesters is curtailed. However, the development of institutions and methods for managing common property resources such as wildlife is a complex task, and in fact each of the methods used to control access to these resources has certain disadvantages.

Setting limits

In modern societies there are three major means of controlling the harvesting of wildlife: (1) the number of harvesters can be limited, (2) the length of harvesting seasons and the techniques permitted in hunting and trapping can be controlled, and (3) restrictions on the harvest itself can be imposed.

Under the first type—the "entry-limiting" method of control—limitations are placed on the number of harvesters allowed to take wildlife—for example, by requiring each harvester to have a license and by limiting the number of licenses. This method indirectly restricts the total wildlife harvest by restricting the number of harvesters. In addition, entry limitations are often established for a particular purpose, such as that of providing a particular group with advantages generally considered its due. In the United States and Canada, for instance, exploitation of some wildlife resources has been reserved for certain native tribes. Another form of entry limiting has been adopted by the many nations that have established 200-mile zones along their coastlines to keep other nations from fishing in these waters.

The problem with attempting to control harvesting by limiting the number of harvesters is that, without other restrictions, nothing prevents harvesters from increasing their efficiency and thereby increasing the harvest. Under such circumstances, the greater combined harvest could well be greater than is desirable for the good of the resource. Thus, limitation of entry as the sole means of control is not likely to be very effective.

The second means of controlling the harvesting of wildlife—the use of "input limiting" methods—involves measures such as prohibiting certain hunting trapping techniques and closing the hunting, fishing, and trapping seasons during part of the year. The employment of these techniques may well have contributed to the resurgence of certain species of U.S. wildlife.

However, such methods are not ideal, either. Ineffective and inefficient limits on inputs such as the length of the harvesting season are especially prominent in fisheries management: cutting back the length of the season has often simply resulted in more intensified effort over a shorter period of time. Suppose, for example, that the unrestricted fishing season in a particular area is three months long and that harvesting firms together would use ten fishing boats to produce a harvest of 300 tons. But suppose further that the desirable harvest from the perspective of wildlife management is only 100 tons and that, in an attempt to achieve this result, authorities limit the fishing season to one month. The fishermen may well respond by expanding the fleet to twenty boats that can harvest 200 tons. Thus, not only or would the harvest be greater than is desirable, but there would also be overinvestment in fishing boats.

The basic problem both with limiting the number of harvesters and with limiting input is that each of these methods has only an indirect effect on the true objective, which is to prevent overharvesting. A more direct means of controlling the harvest is to use "output-limiting" methods. For instance, limitations on the harvest can be achieved by setting a bag limit on the wildlife each harvester can take. As mentioned, bag limits are a prominent feature of state wildlife regulations, especially of those that control sport hunting and fishing, and presumably they have contributed to the restoration of the populations of some U.S. game species.

However, a bag limit may not be effective in limiting the total number of wildlife taken, because the total is also affected by the number of harvesters. Even if a low bag limit is set, a large number of harvesters could take more wildlife than is desirable. In many cases, and especially those involving commercially exploited species, an aggregate quota is necessary. Such a quota involves setting a maximum total limit on the number of wildlife that can be harvested, regardless of how many hunters, fishermen, or trappers are involved. If a total quota can be enforced, it is clearly an effective way of controlling the harvest since it directly affects the harvest volume.

Unfortunately, however, enforcement can prove to be difficult, because violators often can only be detected flagrante delicto. In addition, laying the groundwork for an aggregate quota involves answering several sticky questions. First, how is the total to be allocated among the producers—that is, the harvesters? Deciding on "fair" allocation scheme can be a politically delicate matter. Moreover, an allocation plan can give inappropriate incentives to producers. For instance, a 100-ton quota allocated to fishing firms on the basis of the number of boats the firms owned would encourage overinvestment in fishing boats.

The probable effect of such an incentive is suggested by a similarly inappropriate allocation scheme that for years guided little oil production in Texas. Until the late 1960s, total production from a Texas oil field was tightly controlled and allocated to individual producers in proportion to the number of wells drilled by each. This scheme led to an orgy of drilling that was not only costly in itself but that reduced the overall recoverable potential of each field, even though monthly production was right on target.

A second question that must be addressed in setting total quotas is whether individual allocations are to be considered the property of the assignee or whether they merely constitute a privilege that cannot be passed on if it is not used. If the allocations are considered property, they can be bought or sold. A property approach has the advantage of ensuring that the target harvest is met in the most efficient way, because less efficient harvesters are inclined to sell their allocations to others who can harvest more efficiently. The initial allocation, however, remains a problem.

Setting quotas

Finally, if an aggregate quota system is adopted, at what level should the quotas be set? The standard recommendation of wildlife biologists is that the level of harvest be at "maximum sustainable yield"—in other words, at the maximum level that can be maintained without depleting the resource. Not enough is known about many species, however, to permit setting such quotas with any precision. In addition, populations of some animals wax and wane in a cyclical pattern, so that quotas which are appropriate at one time may not be suitable at another. In these cases, it may be necessary to set variable quotas, which are adapted to the level of a population at different times.

For instance, variable quotas may be a reasonable approach to the management of the Canada lynx, which has one of the most dramatic population cycles found in nature. Lynx harvests in Canada have varied tenfold or more over an eleven-year cycle.

In the nineteenth and early twentieth centuries, overtrapping of lynx, whose pelts are highly desired by furriers, was severe. As a result, by 1940, pelt production had nearly vanished. At about that time the Canadian provinces began to regulate the length of the lynx trapping season. Lynx populations recovered rapidly, and by 1960 the harvest had almost reached the levels of the early nineteenth century. Recovery was probably enhanced in large part by the lack of harvest incentive due to very low pelt prices.

Recent developments, however, give some cause for alarm. According to Statistics Canada, between the harvest peak years of 1971 and 1982, average prices for lynx pelts increased from about $20 to $300 apiece. Despite this huge price increase, the number of pelts harvested in 1982 compared to the number harvested in 1971 dropped between 37 and 73 percent in various Canadian provinces. Given the increase in price, it is difficult to attribute the decline to a lack of interest on the part of trappers. While natural causes may have played a role, it is likely that the decline also resulted from overharvesting during the preceding eleven-year cycle. If so, additional restrictions may be required to maintain stable lynx populations, especially during the lows of the population cycle.

Thus, a variable quota system has been proposed by some lynx researchers. It would consist of curtailing lynx hunting and trapping for several seasons during the troughs of the population cycle. But how is such a variable quota to be allocated? One possibility is to model it on the system that governs rights to water in the western United States. Under this system, an ordering of rights to withdraw water is based on the dates when the rights are claimed. When water is scarce, the more senior rights have priority and are therefore more valuable. Similarly, rights to harvest lynx could be ordered by means such as a one-time-only lottery during the lows of the population cycle. Subsequently, rights could be traded, with higher-priority rights having greater value.

In conclusion, the methods designed to prevent overexploitation of wildlife are less than perfect at responding to the many sets of constantly changing circumstances presented by wildlife resources. Yet, imperfect methods and institutions were largely responsible for the recovery of North American wildlife when a number of species were in a very precarious state. These methods can continue to provide valuable tools for wildlife management in the United States and to complement other approaches being used elsewhere.