The Nigeria-Cameroon chimpanzee, Pan troglodytes ellioti, is the most endangered of four currently recognized subspecies of chimpanzee. Habitat destruction and hunting have driven this chimpanzee to extinction across much of its range in the forests of southern Nigeria and western Cameroon.
In Nigeria the chimpanzee is found in the large forests blocks of Cross River State including Cross River National Park, the Mbe Mountains and Afi Mountain Wildlife Sanctuary. Small groups of chimpanzees still occur in the remaining forest fragments of south-western Nigeria and the Niger Delta although these small and isolated populations are at increased risk of extinction from disease and other unpredictable events. The main stronghold for chimpanzees in Nigeria is in the gallery forests and habitat mosaic of Gashaka Gumti National Park in Taraba State where it is estimated that perhaps 1,000 chimpanzees survive. Estimates of the total chimpanzee population in Nigeria range from 1,400 to 2,300 with similar numbers in south-west Cameroon.