An adult male will communicate aggression or curiosity by standing upright and beating on its chest with its hands. Other forms of communication include huffs, coughs, burps, and hiccups. The undisputed boss of each gorilla group is a mature male with silver hair on his back. Standing over five feet tall and weighing up a 600 pounds, a silverback may have an armspan of eight feet and possess the strength of four to eight strong men. However, the leader is a benevolent dictator, and his authority is rarely challenged.
Females have babies every three to four years.
Gorillas sleep in trees, usually a different one each night. The females and youngsters will build comfortable nests of leaves and branches, while the heavy silverback sleeps at the bottom of the tree to protect his family. The lowland gorilla lives in rain forests from sea level to about 6,000 feet. Limited to small areas in Zaire, Gabon, Equatorial Guinea, Cameroon, and the Central African Republic, the lowland gorilla is an endangered species. Threatened by habitat destruction and human persecution, there may be only about 10,000 lowland gorillas left in the wild.