The Cross River gorillas are the most northern and western of all gorilla populations. The gorillas living in the mountainous landscape between Nigeria and Cameroon at the headwaters of the Cross River were described long ago as a distinct taxon Gorilla g. diehli and this status was recently recognized as correct.

The cross river gorillas are only found in a few forest patches in Nigeria and Cameroon. This western gorilla subspecies is the world’s rarest great ape and differs from the western lowland gorilla in skull and tooth dimensions. With the smallest population of approximately 280 cross river gorillas in the whole world, they are usually found in montane rainforest between 1,500 and 3,500 meters and in bamboo forest from about 2,500 to 3,000 meters.

The global population lives in ranges in elevation from less than 200m in the valleys to 2.000m. Fewer than 300 individuals may remain distributed across 11 highland sites scattered across an area of some 12.000 km². Those gorillas have managed to persist in a region with a dense human population, mostly because of the relative inaccessibility of their forested refuges. It is the most threatened taxon of ape in Africa.

The Cameroon-Nigeria border region, where the Cross River gorilla occurs, is a biodiversity hotspot of global significance that supports a high diversity of animal and plant species, large numbers with restricted ranges, and many of which are threatened. Threatened primates that share parts of the Cross River gorilla’s habitat include the drill (Mandrillus leucophaeus), Preuss’s guenon (Cercopithecus preussi) and theNigeria-Cameroon chimpanzee (Pan troglodytes
elioti).

Successful efforts to secure the future of the Cross River gorilla and its habitat would, therefore, provide a wide range of important conservation benefits. We hope that this plan will assist in guiding the actions needed to improve the conservation prospects for this critically endangered ape (and for this biodiversity hotspot as a whole), and in raising the funds needed to undertake them.