A gorilla is a very large ape. It has long arms, black fur, and a black face. Largest of the great apes. A stocky, powerful forest dweller native to equatorial Africa, the gorilla (Gorilla gorilla) has black skin and hair, large nostrils, and prominent brow ridges. Adults have long, powerful arms; short, stocky legs; an extremely thick, strong chest; and a protruding abdomen. Adult males have a prominent crest on top of the skull and a "saddle" of gray or silver hairs on the lower part of the back. Males, about twice as heavy as females, may reach a height of about 5.5 ft (1.7 m) and a weight of 300-600 lbs (135-275 kg). Gorillas are mainly terrestrial, walking about on all four limbs. They live in stable family groups of six to 20 animals that are led by one or two silverbacked males. They eat leaves, stalks, and shoots. They are unaggressive and even shy unless provoked. They are calmer and more persistent than chimpanzees; though not as adaptable, gorillas are highly intelligent and capable of problem solving. The gorilla is hunted for its body parts and meat, and its habitat is disappearing. It is an endangered species throughout its range; the mountain subspecies is critically endangered