Denver Zoo Map

Gorilla gorilla gorilla



Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Gorilla
Species: gorilla
Subspecies: gorilla


Fun Facts

  • Gorillas are the largest living primates.
  • DNA analysis indicates that gorillas and chimpanzees are more closely related to humans than to orangutans.
  • Gorillas are capable of learning and using sign language to communicate with humans.



The western lowland gorilla ranges through western central Africa, specifically Nigeria, Cameroon, Central African Republic, Equatorial Guinea, Gabon, and Congo.


Lowland, swamp, tropical and montane secondary forests from sea level to 5,249 feet (1,600 m).

Physical Description

  • Western lowland gorillas are four and a half to five and a half feet (1.4-1.75 m) tall.
  • Males weigh 300-600 pounds (136-272 kg), females are smaller weighing 154-300 pounds (70-136 kg).
  • Their fur is predominantly black with a brownish tinge and a reddish-brown cap on top of the head.
  • Adult males develop silver colored fur on their backs.
  • They have an opposable thumb on their hands and an opposable big toe on their feet.


What Does It Eat?

In the wild: Leaves, shoots, pith, stems and fruit.
At the zoo: Vegetables, fruits and primate biscuits.

What Eats It?

Leopards prey on the gorilla. The young are often preyed on by raptors, and un-weaned infants may be killed by male gorillas when they displace a former male leader.

Social Organization

Gorillas are social animals that live in family groups consisting of an adult silverback male, several adult females, and their offspring. Family groups may number from 2 up to 35 individuals but usually consist of five to 10 animals. The adult male and females usually stay together for life while the young leave when they reach maturity. Fighting plays an important role in group hierarchy, though no territorial defenses are exhibited.

Life Cycle

Female gorillas are sexually mature at about seven to eight years of age but usually do not breed until they are ten. Males mature somewhat later and do not breed until they attain silverback status after age 15. Gorillas do not have a distinct breeding season. After a gestation of 250-290 days females give birth to a single infant weighing four to five pounds (1.8-2.3 kg). Twins are rare. Infants are carried against the mother’s chest and later on her back. They begin to crawl at about nine weeks and can walk at 30-40 weeks. Gorillas are weaned between three and four years of age. All members of the gorilla group share in raising and protecting the young. Both males and females normally leave their natal group at about ten years of age. Females may join with an existing group or join with a solitary male to form a new group. Males usually find an area to live in and then attract young females. Western lowland gorillas live between 30-40 years in the wild and up to 50 years in captivity.


Knuckle Down

Gorillas are quadrupedal, meaning they walk on all fours. They walk on the soles of their back feet, but curl the fingers of their hands under and walk on their knuckles. Walking on their knuckles provides strong support for their long arms, and their massive arm, shoulder, and neck muscles.

Can You Hear Me Now?

Although normally very quiet, gorillas make over 20 different vocalizations including roars and growls of aggression, grunts and barks to coordinate group activity and movement and loud hoots that may serve to warn other gorillas away.

Sleeping in the Trees

Each night, gorillas build sleeping nests by bending branches and leaves down to form a platform. These nests keep the gorillas off the cold ground and support them in the trees during the night. They build a new nest each night as they travel around in search of food.

Gorilla Buffet

The gorilla’s large size and the relatively low nutritional value of their diet means they must spend many hours each day feeding in order to maintain their body weight. An adult male gorilla may eat as much as 40 pounds of vegetation in a day. Gorillas have powerful jaws and large teeth needed to grind up the tough plant material in their diet. Gorillas rise early and spend the morning foraging and eating. During the hottest part of the day they rest before beginning to eat again until the sun goes down. In the dense forests, gorillas normally don’t have to travel very far to find enough food.

Conservation Connection

IUCN Status: Critically Endangered.

The western lowland gorilla, while more numerous than other gorilla species, is still an endangered animals. Population estimates are difficult to assess due to the dense forests and constant movement of family groups but there are believed to be only 112,000 western lowland gorillas and the number is declining. Gorillas are endangered due to habitat loss because of logging and agriculture. Recently the hunting of primates, including gorillas, for the growing bush meat trade has further threatened their survival.