Amazing GORILLA Facts 

1. Basics: Gorillas are the largest living primates - the family of animals that includes monkeys, apes, and humans. A mature male gorilla can be over 6 feet tall and weigh 300 to 500 pounds. He can spread his arms 8 feet across and is as strong as 4 to 8 strong men. Adult female gorillas are about half the size of the males. Gorillas also belong to the group of primates called "great apes" which also includes chimpanzees, orangutans, bonobos, and humans.

2. Bodies:  Like humans, gorillas have two legs and two arms, 10 fingers and 10 toes, small ears on the side of the head, forward-looking eyes and 32 teeth. Unlike us, their arms are longer and more muscular than their legs, and their big toes look like thumbs. Their bodies are covered by thick dark hair, except on the face, chest, underarms, palms, and soles of the feet. An adult male gorilla becomes a "silverback" at about age 15 when he is full-grown and the hair on his back turns silvery-gray.

3. Walking: Gorillas normally walk by putting their feet flat and walking on the knuckles of their hands. They can stand upright, but they don't do it very often. When they do, it is often to "chestslap." Gorillas do not beat their chests with their fists but with open cupped hands, making the familiar loud sound, which can indicate aggression or excitement.

4. Life Span: Gorillas can live more than 50 years. Newborn gorillas are very small, weighing only about 4 1/2 pounds. They are helpless at birth and depend on their mothers for at least 3 years, and they usually stay in their family group as they grow up. Females mature at 10 to 12 years and males at 11 to 13 years. Young gorillas must learn from their group how to find food, make nests, take care of babies, and get along with other gorillas.

5. Communication: Gorillas communicate with each other by using gestures, body postures, facial expressions, vocal sounds, chestslaps, drumming, and odors. Although they cannot make the sounds of human speech, gorillas are capable of understanding spoken languages and they can learn to communicate in sign language.

6. Intelligence: Gorillas are very intelligent, and they share with us a full range of emotions: love, hate, fear, grief, joy, greed, generosity, pride, shame, empathy, and jealousy. They laugh when they are tickled and cry when they are sad or hurt. Gorillas cry with sounds, not tears.

7. Family: A typical gorilla family includes one silverback, the strongest male and the undisputed leader; one immature male between 8 and 13 years old; three or four adult females, who ordinarily stay with the silverback for life; and three to six youngsters under 8 years old. Some groups are larger or smaller than this, and males sometimes travel alone or form bachelor groups.

8. Sleeping and Eating: Gorillas sleep about 13 hours each night and rest for several hours at midday. They build new sleeping nests every night by bending nearby plants into a springy platform, usually on the ground or in low trees. When not resting they spend most of their time looking for food and eating it. They eat mostly plant foods: leaves, shoots, fruits, bulbs, bark, vines, and nettles. They also eat ants, termites, grubs, worms, and insect larvae.

9. Gorilla Types (Subspecies): There are four types of gorillas: Western Lowland, Eastern Lowland, Cross River, and Mountain gorillas. The names refer to the different areas of Africa where they live. Mountain gorillas are the most critically endangered, with conservative estimates of only 400 to 600 living at this time. Koko and Michael, and most zoo gorillas, are Western Lowland gorillas.

10. Endangered Status: Gorillas are shy and peaceful. The only natural enemy of gorillas has always been human beings. Gorillas are still hunted for meat (bushmeat) and trophies in some parts of Africa, and they are caught in traps set for other animals. In the past, whenever an infant gorilla was captured for a zoo, the mother and often the other members of the family were killed as they defended the baby. Now the most serious threat to free-living gorillas is the human population explosion. As more and more people take over the land for agriculture, logging, and other development, the gorillas have nowhere left to go.


Learn more about Gorillas. Check out these Gorilla Books:

Gorilla Rescue
by Jill Baily. Steck-Vaughn, 1990.

Apes in Fact and Fiction
by Gilda Berger. Watts, 1980.

Mountain Gorilla
by Michael Bright Gloucester Press, 1989.

Monkeys and Apes of the World
by Rita Golden Gelman. Franklin Watts, 1990.

Signs of the Apes, Songs of the Whales
by George Harrar. Simon & Schuster, 1989.

Raising Gordy Gorillas at the San Diego Zoo
by Georgeanne Irvine. Simon & Schuster, 1990.

Thinking Gorillas
by Bettyann Kelves. E.P. Dutton, 1980.

Monkeys and Apes
by Kathryn Lumley. Children's Press, 1982.

by Rober McClung. William Morrow, 1984.

With Love from Koko
by Faith McNulty. Scholastic Inc., 1990.

The Truth about Gorillas
by Susan Meyers. E.P. Dutton, 1980.

Koko's Kitten
by Francine Patterson. Scholastic Inc., 1985.

Koko's Story
by Francine Patterson. Scholastic Inc., 1987.

The Education of Koko
by Francine Patterson and Eugene Linden. Holt, Rinehard & Winston, 1981.

Why Chimps Can Read
by Ann J. Premack. Harper & Row, 1976.


Contact Us



The Gorilla Foundation / Koko.org
1733 Woodside Rd., Suite 330
Redwood City, CA, 94061
1-800-ME-GO-APE (634-6273)

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Our mission is to learn about gorillas by communicating with them, and apply our knowledge to advance great ape conservation, education, care and empathy.

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