|SCIENTIFIC NAME: Gorilla gorilla gorilla|
|RANGE: Cameroon, Gabon, Republic of Congo, Central African Republic and Equatorial Guinea|
|HABITAT: forests, lowland swamps|
|DIET: wild celery, bamboo, vines, herbs, bark, leaves, berries, fruit and insects|
Largest of all primates, the western lowland gorilla has black-gray hair covering its entire body except for the face, upper chest (male only), ears, palms and soles. The adult male, called “silverback,” has silver-gray hair on his back, extending to the rump and upper thighs. The hands and feet are broad, with thick digits, and the arms are longer than the legs. Mainly terrestrial, the gorilla walks on its knuckles (quadrupedal knuckle walk). The average adult male height is five-to-six-feet, weight 370-to-400 pounds; average adult female height is five feet, weight 160-to-200 pounds
The animals live in small groups of three-to-20 animals, led by an adult male. Leafy platforms are built in trees, or on the ground, for sleeping or resting. Most of the day is spent playing, resting and foraging. Nomadic as a rule, the groups do have a home range they regularly visit. Chest beating occurs as a response to a threat, tension release or a sign of curiosity.
There is no specific breeding season. Gestation lasts 250-to-285 days, followed by a single birth, rarely twins. An infant averages four-to-five pounds at birth and is dependent on its mother for about three years. Females are sexually mature by age six or seven; males by age 10 or 11, when the hair begins turning silver.
Western lowland gorillas make up most of the captive population in the world; only a handful of eastern lowland gorillas live in captivity. Average life span is 50 years.
In the spring of 2000, primatologists reclassified gorillas into two species and five subspecies, listed in descending order from most endangered to least endangered: Cross River gorilla (Gorilla gorilla diehli); mountain gorilla (Gorilla berengei berengei); Bwindi gorilla (no scientific name yet); eastern lowland gorilla (Gorilla berengei graueri); western lowland gorilla (Gorilla gorilla gorilla).