The western gorilla (Gorilla gorilla) is a great ape, closely related to both chimpanzees, orangutans and humans. They are the type species as well as the most populous species of the genus Gorilla. Nearly all of the individuals of this taxon belong to the western lowland gorilla subspecies. The other subspecies are the Cross River gorilla.
Western gorillas are generally lighter colored than eastern gorillas. Western lowland gorillas have black, dark grey or dark brown-grey hair with a brownish forehead. Measurements of wild individuals show that mature males average 155 cm (61 in) in height.