A Preliminary Report on the Impact of Chimpanzee Hunting on Mammal Populations at Mahale, Tanzania

Abstract

The impact of chimpanzee hunting on populations of several mammalian species was examined by analyzing the data of population census on these mammals and the previous reports of chimpanzee hunting at the Mahale Mountains National Park, Tanzania. The annual kill rates (1.3-9.0%) of red colobus monkeys by the chimpanzees were estimated to be almost the same as the population growth rate of this species. These kill rates were equal or slightly higher than those reported from the Tai National Park, Ivory Coast, but extremely lower than those reported from the Gombe National Park, Tanzania. The impact of chimpanzee hunting on other prey mammals (redtailed monkey, blue monkey, blue duiker, bushbuck and warthog) seems to be small, because the annual kill rates of these species by the chimpanzees were estimated to be smaller than their population growth rates or the hunting frequencies on them by the chimpanzees were very low.