Overhunting is any hunting activity that has an adverse impact on the total continuing population of a species . With the tremendous increase in the human population since the industrial revolution, there has been an ever increasing use and, often, exploitation of many of the world's natural resources . The demand for fish and shellfish has exemplified this misuse of natural resources. The amount of hunting pressure that a species can tolerate depends on its productivity, and it may change seasonally and annually because of drought , habitat alteration, pollution , or other mortality factors. Hunting which is well-regulated can be sustained, and sportsmen in countries with regulated hunting are quick to point out that they are not responsible for the endangerment or extinction of any species.
In unregulated situations, however, overhunting does occur, and it has endangered wildlife , even driving some species to extinction. The great auk (Alca impennis ), a large, flightless, penguin-like bird of the North Atlantic coasts, was so easy to catch that sailors could kill hundreds in a few minutes, and by 1844 they had become extinct. Even the world's most abundant bird, the passenger pigeon (Ectopistes migratorius ), was driven to extinction by overhunting. In the 1800s there were 3 to 5 billion passenger pigeons, about one-fourth of all North American land birds, and enormous flocks of them would darken the sky for days as they flew overhead. One colony in Wisconsin covered 850 square miles (220,149 ha) and included 135 million adult birds. Commercial hunting sent train loads of these birds to markets, including 15 million birds from a single colony in Michigan, and eliminated the species in the early 1900s.
There are several cases where overhunting has nearly exterminated a species. In 1850 there were 60 million American bison (Bison bison ) on the Great Plains of the United States, and within 40 years, overhunting had reduced the wild population to 150 individuals. At the turn of the century, snowy egrets (Leucophoyx thula ) were almost wiped out by hunters who the sold the feathers to be made into fashionable women's hats. Many species of whales were also driven to the brink of extinction by whalers.
Many species continue to be overhunted today. Although protected by law, African rhinoceroses are endangered by poachers who sell the horns to Yemen and China. In Yemen the horns are used to make dagger handles for wealthy businessmen, and in China they are made into an aphrodisiac and fever-reducing drug which is reportedly useless. Likewise, elephants are being slaughtered for their ivory tusks. There were 4.5 million elephants in 1970, and by 1990, only 610,000.
Many large cat species are also threatened by overhunting, because the economic incentive to poach these animals far outweighs the risks of being caught and fined. For example, a Bengal tiger (Panthera tigris tigris ) fur coat sells for $100,000; an ocelot (Felis pardalis ) skin sells for $40,000; a snow leopard (Panthera uncia ) skin sells for $14,000; and tiger meat sells for $629 per pound ($286/kg).
Even when appropriate hunting regulations do exist, there are often not enough rangers or conservation officers to enforce them. As species become more scarce, the demand increases on the black market, inflating the price, and the economic incentive for poaching only becomes greater. Unless appropriate laws are enacted and enforced other species will become extinct from overhunting.
See also Conservation; Convention on International Trade in Endangered Species of Fauna and Flora; Defenders of Wildlife; Endangered species; Endangered Species Act; Fish and Wildlife Service; IUCN—The World Conservation Union; Wildlife management; Wildlife rehabilitation
[Ted T. Cable ]
Owens, D., and M. Owens. Eye of the Elephant: Life and Death in an African Wilderness. New York: Houghton Mifflin, 1992.
Jackson, P. "They've Shot Miro." International Wildlife 22 (November-December 1992): 38–43.