Apes

Gorillas (Gorilla gorilla) inhabit forests of Central Africa and are the largest and most powerful of all primates. Adult males stand 6 ft (1.8 m) upright (although this is an unnatural position for a gorilla) and weigh up to 450 lb (200 kg), while females are much smaller. Gorillas live to about 44 years old. Mature males (older than about 13 years), called silverbacks, are marked by a band of silver-gray hair on their back.

Gorillas live in small family groups of several females and their young, led by a dominant silverback male. The females comprise a harem for the silverback, who holds the sole mating rights among males in the troop. Female gorillas produce one infant after a gestation period of nine months. The large size and great strength of the silverback are advantages in competing with other males for leadership of the group and in defending against outside threats. Despite its ferocious image to some people, the gorilla is not an aggressive animal. Even in a clash between two adult males, most of the conflict consists of aggressive posturing, roaring, and chest-beating, rather than physical contact.

During the day these ground-living, vegetarian apes move slowly through the forest, selecting leaves, fruit, and stems from the vegetation as food. Their home range is about 9–14 sq mi (25–40 sq km). At night the family group sleeps in trees, resting on platform nests that they make each evening from branches; silverbacks usually sleep near the foot of the tree.

Gorilla numbers are declining rapidly and only about 50,000 remain in the wild. Other than humans, gorillas have no real predators, although leopards will occasionally take young individuals. Hunting, poaching (a live mountain gorilla can be worth $150,000), and habitat loss are causing gorilla populations to decline. The trade of gorillas has been banned by the countries where they occur and by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), but they are nevertheless threatened by the illegal black market. The shrinking forest refuge of these great apes is being felled in order to accommodate the needs of the ever-expanding human population in Central Africa.