Gorillas are the largest primates in the world today. There are two gorilla species separated into four different types of gorilla. All of these types, or subspecies, are native to the African continent. Gorillas are an endangered species, with only one of the subspecies, the western lowland, having a significant population. Exact counts of gorilla populations are difficult as the shy apes live in secluded tropical and subtropical forests.
The two species are the eastern gorilla, Gorilla beringei, and the western gorilla, Gorilla gorilla. The western species has two subspecies: the western lowland gorilla, G. gorilla gorilla, and the Cross River gorilla, G. gorilla diehli. Eastern gorillas consist of two types of gorilla: the eastern lowland gorilla, G. beringei grauen, and the mountain gorilla, G. beringei beringei.
Western lowland gorillas are native to several areas of Africa including Angola, Congo, and Cameroon. This is the type of gorilla that is frequently seen in zoos. The western lowland is the smallest of the great apes. Adults are about 5 feet 7 inches (1.7 meters) tall and weigh 400 pounds (180 kg). As of 2008, there were an estimated 125,000 western lowland gorillas living in Africa.
Eastern lowland gorillas are the next most populous, with less than 5,000 living in the wild. These great apes live only in the forests of the Democratic Republic of the Congo. They are the largest of the gorillas, with an average height of 6 feet 6 inches (2 meters) tall and weight of 550 pounds (250 kg).
Most mountain gorillas live in the Virunga Mountains of central Africa. Small populations of these apes live in the Bwindi Impenetrable National Park in Uganda. Between the two populations, there are only about 700 left in the wild. Mountain gorillas have longer fur than other gorillas, suiting their cooler mountain environment.
The Cross River gorillas are the rarest of all types of gorilla, with only 300 left in the wild. They are found in the border areas between Cameroon and Nigeria. These gorillas are very similar to western lowland apes. The main differences between the two subspecies are the teeth and skull measurements.
All types of gorilla are considered critically endangered. They are vulnerable to habitat destruction, poaching, and disease. The clear-cutting and development of the gorilla’s natural habitats have been pushing remaining populations into smaller areas. Many of them live in protected sanctuaries but still fall victim to illegal poaching. The Ebola virus has been especially destructive, wiping out large sections of gorilla populations.