Found only in the central portion of Democratic Republic of the Congo (Congo Basin), south of the Congo river. The common chimpanzee has much larger range.
Small populations within the Congo Basin are separated by rivers.
Potential range is estimated at approximately 500,000 km sq. (193,051 mi sq)
Range is discontinuous. Species absent or rare in many areas. Southern part of Congo Basin not well surveyed.
Few field studies prior to 1970s. Studies in 1980s confirmed populations near towns of Befale, Djolu, Bokungu and Ikela and a 3,000 sq. km. area between the Yekokora and Lomako Rivers.
Based on evidence of nest building individuals, population densities of around 0.4/sq km (0.15/ sq mi) are estimated for Salonga National Park which may be similar to overall densities for all their range; some study area have higher estimates.
As late as 17th century this species may have ranged into northwestern Angola and as far south as the Quanza River.
Habitat
Found in lowland rain forest - both primary and secondary "regrowth" forests, but also in mosaic forest with savannas where they may even feed on grasses; recent studies show them entering swamp forests where they wade in waist-deep streams.
Share many ecological traits with common chimpanzees. Both are terrestrial and arboreal. Can utilize many plant resources.