Common chimpanzees (historically also referred to as the “robust” chimpanzees, to distinguish them from the “gracile” chimpanzees, or bonobos) are found in tropical moist forests, grassland-forest mosaics and savanna woodland habitats from sea level to about 3,000m elevation.
Chimpanzees are widely distributed in 21 countries across Equatorial Africa, between 13°N and 7°S (Angola, Burundi, Cameroon, Central African Republic, Rep. of Congo, Dem. Rep. of Congo, Côte d'Ivoire, Equatorial Guinea, Gabon, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Nigeria, Rwanda, Senegal, Sierra Leone, Sudan, United Rep. of Tanzania and Uganda).
In 2003, the total chimpanzee population was estimated between 172,700 and 299,700 individuals (Butynski, 2003). These estimates were largely obtained by extrapolating results from small surveyed areas to large areas of potential great ape habitat, thus likely resulting in over estimates.
Chimpanzees are omnivorous, largely selecting ripe fruit whenever it is available. Their diet, which has high seasonal and regional variations, also includes leaves, seeds, stems, pith, bark and a small but important animal component including insects, birds, birds' eggs, and small to medium-sized mammals (reviewed by Inskipp, 2005).
Chimpanzee hunting behavior on red colobus monkeys, their most frequent prey, is particularly complex (Boesch et al. 2002). The social system in which chimpanzees live is referred to as fission-fusion (Milton, 2000): a few to over 100 individuals live in social communities in which sub groups emerge and dissolve often within a day.
The male members of the community (sometimes joined also by females) actively defend the borders of their territory from males of neighboring communities, occasionally engaging in war-like aggressive interactions (Boesch and Boesch-Achermann, 2000; Boesch et al. 2007; Goodall 1986; Wrangham and Peterson 1997; Watts et al. 2002).
Status (IUCN 2010): ENDANGERED.
Listing justification (Oates et al. 2008a - see also individual subspecies listings): «Although Chimpanzees are the most abundant and widespread of the apes, with many populations in protected areas, the declines that have occurred are expected to continue to occur, satisfy the criteria for ranking as Endangered.
Due to high levels of exploitation, loss of habitat and habitat quality due to expanding human activities, this species is estimated to have experienced a significant population reduction in the past 20 to 30 years (one generation is estimated to be 20 years) and it is suspected that this reduction will continue for the next 30 to 40 years.