With fewer than 300 individuals estimated to exist inthe wild, the CrossRivergorilla is theworld’s rarest greatape. CrossRivergorillas differ from other western gorillas by their slightly smaller skull and teeth. They live in family groups led by a dominant male, the silverback, surrounded by females and young. They feed mainly on fruit, leaves, stems, and tree bark. Strategy meeting during the CrossRivergorilla conservation workshop, in Douala, Cameroon. For many of the organisations involved, the workshop represented an important milestone in building stronger partnerships and sharing knowledge across the region. GreatApes: All 4 Gorillas Subspecies | Crossrivergorilla, Wildlife conservation society, Gorilla.They have differently shaped skull from western lowland gorillas, but are also redder and greyer and than the eastern subspecies. They are themostelusive and hardest to study gorilla. CrossRiverGorillas (Gorillagorilla diehli).It’s estimated that the population has declined by more than 75% over the last two decades, making them one of themost threatened greatape populations intheworld. Gorilla Tourism and Conservation Efforts in Kahuzi-Biega. Only around 300 CrossRivergorillas were known to be alive inthe area, noted WCS. Although illegal hunting is common inthe area, the CrossRivergorilla is rarely a target of such activity, says WCS. Central equatorial Africa is home to two gorilla species: eastern gorillas (Gorilla beringei) and western gorillas (Gorillagorilla). The distance between both species is not great following their divergence, which began between 0.9 and 1.6 million years ago.