Dutch researchers have mapped globally the impact of this practice on the size of animal populations.
In the shade of the canopy, the hunt rages and destroys, gradually reducing the forest to silence. The consequences of this practice on mammal populations are already visible in nearly half of the world's tropical forest areas, according to a study published Tuesday, May 14 in Plos Biology.
"Even in forests that were thought to be intact from satellite imagery, wildlife is affected by hunting"says Ana Benitez-Lopez, an ecologist at Radboud University (Netherlands) and first author of the study. By mapping, unprecedented on a global scale, the level of "Defaunation" caused by hunting, the researchers wanted to draw attention to a phenomenon that is still insufficiently taken into account in the various estimates of the overall state of biodiversity.
For this purpose, they analyzed the field data of 163 studies published between 1980 and 2017 on 296 species and incorporated them into a mathematical model allowing them to estimate the pressure exerted by hunting on all mammal species. living in tropical forests, nearly 4,000.
Result: in the tropics, the decline of mammals, all species combined, amounts to 13% just because of hunting. If the very small animals are relatively spared, the loss is 27% for medium-sized mammals (between 1 and 20 kg) and 42% for those over 20 kg. West Africa, Central Africa, Latin America, northwestern South America and parts of Southeast Asia are among the most affected regions. In Cameroon, for example, more than half of the mammalian species have lost at least 70% of their numbers.
In most cases, these animals are killed to meet the food needs of local people, or because they are an attractive source of income, with wild meat being considered a luxury product in urban areas. Ana Benitez-Lopez. But there are also other reasons, such as the trafficking of live animals or organs (skins, horns …).
"The giant pangolin, for example, is highly prized for its scales, which are used in traditional Chinese and Vietnamese medicine, notes the researcher. Our model shows a 45% loss of its numbers in the tropics because of hunting. "