As hunting is increasingly to feed into the commercial trade, we see a typical “boom and bust” pattern at any one site – hunting rates initially increase when markets become accessible, then rapidly decline again as wildlife populations are depleted. As populations of a desired species in one area decline, markets seek their supplies from other species or other areas, causing ever-increasing circles of loss.
Hunting in Bioko, Equatorial Guinea, has reduced primate populations by 90% in some areas and to local extinction in others. In one forest in Kenya, hunting has reduced large ungulates to such low levels that it is no longer worthwhile hunting them. In Kilum Ijim, Cameroon, within the past 50 years, most large mammal species have become extinct as a result of hunting, including elephants, buffalo, bushbuck, chimpanzees, leopards, and lions. Even in Amazonia with its extremely low human populations, wildlife populations are down by an average of 81% in heavily hunted areas.
In Asia, the picture is especially worrying. Half of the major protected areas in South-east Asia have lost at least one species of large mammal due to hunting, and most have lost many more. In Doi Inthanon and Doi Suthep National Parks, northern Thailand, all elephants, tigers and wild cattle hunted out, as have all of the primates and hornbills in Kubah National Park, Sarawak, Malaysia. All available data indicate that pangolins are disappearing throughout their natural range across Asia, largely as a result of trade. With three tiger subspecies already extinct and perhaps fewer than 5,000 left in the wild across Asia, tigers have begun disappearing from their last strongholds. This is exemplified by survey results announced in 2005 that the famous Project Tiger site of Sariska National Park, India, has no tigers left. Even if tigers themselves are not hunted, human hunting in parts of India results in reductions of more than 90% of their ungulate prey. More than 50% of Asia’s freshwater turtle species are now listed as endangered due to over-harvesting for trade. And in Vietnam, 12 species of large animals have become extinct, or virtually extinct, in the past 50 years mainly due to hunting.
The “empty forest syndrome” – beautiful forests which are becoming increasingly silent as their wildlife is being hunted out -- is now a reality throughout much of Asia and West Africa, and is spreading rapidly to other parts of the tropical forest world.
Outside tropical forests, wildlife trade can also have dramatic effects on wildlife populations. In Mongolia, within just five years, saiga antelope declined catastrophically from over 5,000 to less than 800. Between 1986 and 2004, the numbers of red deer went from 130,000 to 8,000-10,000. Marmots once numbered more than 40 million; their numbers dropped to around 20 million by 1990, and by 2002 were down to only 5 million.