There are three recognized subspecies of gorilla, the western lowland gorilla (Gorilla gorilla gorilla), eastern lowland gorilla (Gorilla gorilla graueri) and the mountain gorilla (Gorilla gorilla beringei). The western lowland gorilla lives in six countries across west equatorial Africa; southeast Nigeria, Gabon, Cameroon, Central African Republic, Congo and Equatorial Guinea.

All gorillas live in primary and secondary tropical rain forests. Different subspecies range throughout various altitudes, from sea level to 12,500 feet (3,790 m). Estimated up to 50 years in the wild. Average 30-35 years in zoos. Record is 54 years.

Gorilla, is the largest of the apes, the males reaching a height of 5 to 6 ft (150?190 cm) with a 9-ft (144?cm) arm spread. Males weigh about 450 lb (200 kg) in the wild; in zoos they become obese and may reach 600 lb (270 kg) or more.

Male gorillas have prominent sagittal crests and brow ridges and large canine teeth; these features are less developed in females. Females are smaller than males, weigh about half as much, and do not develop the gray hair on the back characteristic of the sexually mature male.

Their main enemies are human poachers; in the lowlands, leopards may sometimes eat the young. Females bear one infant about every four years; the child is carried in the mother’s arms and then on her back. Females mature in 8 or 9 years, males in 11 or 12. Gorillas are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Primates, family Pongidae.

A family group includes one dominant silverback male, several adult females, adolescents, juveniles and infants. The group may also include one or two subordinate silverbacks. All adult males are silverbacks. A dominant male silverback and group females usually stay together for life. Although gorillas are normally not aggressive, they can exhibit certain aggressive actions when disturbed.

Adult males perform elaborate displays, including chest beating, running sideways and tearing up vegetation to frighten off an intruding male or other threat. Males also use these displays as a show of dominance within the group. Adult females can become aggressive when defending their infants, or while helping each other drive off rowdy, young adult males. The silverback is the peace keeper and stops occasional squabbles between females.

Gorillas are incredibly powerful, the largest great ape in the world. Regardless of their imposing appearance, they are in fact quite shy, gentle animals. Gorillas are virtually vegetarian and forage throughout the day in search of a variety of plants to consume. The hair of the western lowland gorilla is grayish-black and usually reddish on their head (particularly prominent in adult males). At about age 10, males begin to grow the distinctive silver-white saddle of hair on their back, which in western lowland gorillas continues to extend down the rump and thighs as the male gets older. Mountain gorillas have darker, longer hair.