Cross River gorilla

SCIENTIFIC CLASSIFICATION

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Gorilla
Species: G. gorilla
Subspecies: G. g. diehli

The Cross River gorilla was unknown to science until the early 20th century. Only found in a few forest patches in Nigeria and Cameroon, this western gorilla subspecies is the world’s rarest great ape.

Key facts

• Common name

  Cross River gorilla

• Scientific name

  Gorilla gorilla diehli

• Location

  South-eastern Nigeria and western Cameroon

• Population

  Around 250-300 individuals

• Status

  Critically Endangered

Physical description 

The Cross River gorilla is a subspecies of the western gorilla. It differs from from the other subspecies, the western lowland gorilla, in skull and tooth dimensions.

A high-altitude life

The Cross River gorilla is usually found in montane rainforest between 1,500 and 3,500 meters and in bamboo forest from about 2,500 to 3,000 meters. 

Population & distribution

The Cross River gorilla is restricted to a small area of highland forest on the border of Cameroon and Nigeria. 

This restricted distribution to highland areas is likely a consequence of human hunting pressure and competition over habitat, which is more intense in lowland areas.

With a population of only around 250-300 divided into several sub-populations, some of which number no more than 20 individuals, it is currently the world’s rarest great ape.

What are the main threats?

Habitat loss
Many Cross River gorilla groups live in unprotected forest and face the threat of habitat loss through logging and as local people clear land for agriculture and cattle grazing. 

Hunting
As forests are opened up by timber companies, hunters move in. 

Loss of genetic diversity
The subspecies also faces the risk of inbreeding and loss of genetic diversity due to the small population size and the low flow of genetic exchange between the different subpopulations.

Although areas of unoccupied potential gorilla habitat still remain and can provide connectivity between the subpopulations, these areas are not yet safe for gorillas to use.