The global decline of primates.

• Author: Tuxill, John
• Position: Includes related article on the maias of Sarawak

And it's not just the number of hunters that is increasing; the growing use of guns is increasing the efficiency of the hunting as well. Even in remote regions, hunters who once relied upon nets, snares, and blowguns now have access to powerful shotguns, which are often introduced by traders, miners, or loggers. Scientists have combined field data like that collected by Carlos Peres, with computer models to show that the introduction of shotguns into a community can lead to local extinctions of the larger, more slowly reproducing primates in only 20 to 30 years.

But subsistence hunting is overshadowed in many areas by unregulated commercial hunting. In much of central Africa, a deadly synergism between market hunters and the trade in tropical hardwoods is pushing primate and other wildlife populations into rapid decline. Selective logging practices are not themselves a major problem for most primates. They may even benefit certain species like gorillas, which prefer foods found in secondary forest patches. Logging roads, however, are a different story. By providing access to formerly isolated forests, the roads offer a short-term bonanza for hunters who pursue wild game to supply the growing trade in "bush meat." The numbers of primates, antelope, forest hogs, civets (a cat-like animal), and other creatures killed for bush meat in central Africa are staggering. In Gabon, a country of about 1.2 million people, some 8 million pounds of bushmeat are consumed annually, half of it in urban areas. Primates are a large component of this total - in neighboring Equatorial Guinea they constitute up to 25 percent of the bushmeat marketed. In many areas, the trade in bushmeat is now the main source of income for rural residents.

The complicity of logging operations in the bushmeat trade is blatant and widespread. In one study in the Republic of Congo (not the former Zaire, but the country to the west of it), researchers found that logging company employees supplemented their income by supplying local hunters with weapons, ammunition, and transport in exchange for a share of the meat. According to some experts, bushmeat hunting in central Africa may even outrank habitat loss as a threat to primates and many other forest animals.

Overhunting damages more than just the primate populations themselves. Hunters tend to target the big primates - and big primates usually have big ecological roles. The collapse of their populations may trigger a cascade of ecological effects throughout an entire natural community. In the American tropics, for instance, spider and wooly monkeys consume large quantities of wild fruit while foraging over wide areas of forest. Many tree species rely heavily on these monkeys to disperse their seeds. When the monkeys are hunted out of a forest, some types of trees may not be able to "sow" their seeds properly. If no more seeds land in suitable sites, then the next generation of those tree species is in trouble - and so is the next generation of the birds, mammals, insects, fungi, and various other creatures that the trees support.

Some trees may depend entirely on this dispersal mechanism for survival. In central Africa, for instance, lowland gorillas feed on the fruits of the moabi tree. (So do the people, and other parts of the tree are valuable too: the seed oil is used for cooking, the bark for medicine, and the lustrous wood for furniture.) Moabi seeds are huge - as are the seeds of certain other central African trees. But Melissa Remis, an anthropologist who has studied the gorilla, says the gorilla's guts can accommodate seeds up to 12 centimeters long. "If it weren't for them and for elephants," she says, "trees like moabi might not exist."

Some hunters are pursuing primates not for bush meat, but for the pet trade. Most nations have enacted laws to restrict or ban the trade in wild primates, and most countries that have wild primate populations are party to the Convention on International Trade in Endangered Species of Flora and Fauna (CITES), which essentially bans international trade in endangered species. But the regulations are unevenly enforced, and illegal trade continues within and between many countries, especially in Asia. As recently as 1995, vendors in the Pramuka market in Jakarta, Indonesia were offering dozens of live primates for sale, and a researcher visiting the market was told that live orangutans could be purchased nearby. Orangutans and the other apes - gibbons, chimps, and gorillas are especially charismatic; they are so much like us that there is a virtually insatiable demand for them. Wild-caught infant apes are continually being sought by unscrupulous carnivals, by restaurants and bars to entertain their customers, and by people who just think they would make great pets.

One of the most egregious episodes of ape-smuggling occurred in Taiwan...