The Critically Endangered western chimpanzee declines by 80.

African large mammals are under extreme pressure from unsustainable hunting and habitat loss. Certain traits make large mammals particularly vulnerable. These include late age at first reproduction, long inter-birth intervals, and low population density.

Distribution of chimpanzees and interactions with humans in Guinea-Bissau and western Guinea, West Africa.

To clarify the distribution and the status of chimpanzees in Guinea-Bissau and on the border with Guinea, we conducted an interview survey with hunters in 110 and 60 villages in Guinea-Bissau and Guinea, respectively. Based on the results of the survey, the northern distribution limit of chimpanzees in Guinea-Bissau appears to be located between the Corubal river (which once was suspected to represent the distribution limit) and the Gabù-Bafata road. Chimpanzees were reported to be common in most of the surveyed area and are not a game species.

Estimating primate densities using home range and line transect methods: A comparative test with the black colobus monkeyColobus satanas.

The line transect method is one of the main methods used to estimate primate densities. Several protocols have been proposed to analyze the data recorded under this method but none of them have been widely accepted since there is a considerable controversy about their respective accuracy. In this study, densities of the black colobus monkeyColobus satanas calculated using eight different protocols were compared with the actual density given by the home range method.