Chimpanzees are under threat in most parts of their range through a combination of habitat loss, fragmentation, poaching for bushmeat and/or the pet trade, and increased exposure to diseases carried by humans. Both chimpanzee species are classified as Endangered on the IUCN Red List. Over the course of the past century, the continental population of the common chimpanzee has plummeted from more than one million individuals to fewer than 200,000, and while communities protected in national parks in the likes of Uganda and Tanzania are reasonably secure, the same cannot be said for chimps living in unprotected areas. Bonobos have a limited range in a war-torn part of the Congo and the total population is open to conjecture, but it could be as low as 15,000, some of which are protected in Salonga National Park, a UNESCO World Heritage Site.

Chimpanzees are equally comfortable moving on the ground or clambering through the trees where they feed by day and sleep in temporary nests at night. They are very mobile animals and often cover large daily distances as they search for fruit and/or patrol their territorial boundaries. As a result, tracking chimpanzees can be a lot more tiring than tracking gorillas. When chimps do settle down, however, it can be highly entertaining to watch them grooming, playing and squabbling in a decidedly human-like fashion. A thrilling aspect of chimp behavior is the resounding ‘pant-hoot’ call, a riotous group-bonding ritual that allows all chimpanzees within earshot of each other to announce their presence with a unique vocal stylization.

Although chimpanzees are primarily vegetarian, they are also active hunters and quite frequently kill monkeys. They regularly feed on termites and carpenter ants, ‘fishing’ for them using modified sticks, a rare example of tool usage among animals.

Chimpanzees form well-defined and stable communities of up to 100 individuals, but tend to move around in small, socially mobile subgroups. Males retain a life bond with the community into which they were born, but females usually migrate between communities at adolescence. Each community has an alpha male, though fraternal coalitions are not uncommon. The role of the alpha male is relatively benevolent; he might occasionally monopolize an oestral female, but the more normal intra-community state of sexual affairs is non-hierarchical promiscuity. Inter-community hostility occasionally erupts into protracted warfare that might result in all the males in one or other community being killed by their rivals.