The Nigeria-Cameroon chimpanzee is endemic to West Cameroon and South-East Nigeria. It is the rarest and least studied subspecies of chimpanzees with less than 6,500 individuals in the wild.

To date, this shy and mostly terrestrial guenon has only been studied in Kilum-Ijim forest (North-West region of Cameroon).

Forever inseparable, forever enemies. This is how the relationship between these two massive river lovers would be best described.