Great Apes

by Marcia Malory

Great apes are primates that belong to the family Hominidae. They include gorillas, orangutans, bonobos, chimpanzees and human beings.

All great apes share 97% of their DNA.

The closest relatives to the Great Apes are the gibbons, or Lesser Apes.

Great apes, gibbons and old world monkeys all belong to the superfamily Hominoidea. They are more closely related to one another than to new world monkeys.

Gorillas, chimpanzees and bonobos are found in the wild in central Africa. Orangutans are native to Sumatra and Borneo. Human beings can be found almost everywhere on Earth.

GorillaGreat apes are the largest of all the primates. Males are larger than females of the same species.

All great apes have opposable thumbs.  All except humans have opposable big toes.

Great apes do not have tails.

One of the most important physical features of great apes is their large braincase. Great ape brains are large and highly developed; great apes display high level mental activities including tool use, engagement in complex social behaviors and self awareness - all great apes can recognize themselves in a mirror.

Human beings can use language, and all of the other great apes have shown some rudimentary language ability.

A great ape will usually give birth to one offspring at a time.  Great ape young depend on their parents for a very long time.

All of the great apes, except for human beings, are endangered.

Great Ape Language

The ability to communicate via language is one of the defining characteristics of human beings.

Researchers have shown that other great apes have the ability to develop language skills.  They have been taught to communicate using sign language and lexigrams (symbols that stand for words).

Non-human great apes can understand relatively complex sentences.  They can use language to talk about things that are not present and to ask for things. They can combine words that they already know to express different concepts.

In the 1960s, Allen and Beatrix Gardner raised a chimpanzee named Washoe and taught her American Sign Language. She was able to learn over 300 words and to combine them to create new meanings.

Between 1971 and 1976, Sue Savage-Rumbugh and Duane Rumbaugh taught a chimpanzee named Lana (after Language Analog Project - LANA) at the Yerkes National Primate Research Center. Lana was taught to communicate by using a keyboard with lexigrams. She was able to ask questions and developed the ability to put words in an order that made sense gramatically.

Later, Sue Savage-Rumbaugh taught two chimpanzees named Sherman and Austin to use the LANA keyboard. Sherman and Austin have used language to communicate directly with one another and to make plans together.

A one-year old gorilla named Koko began learning how to use sign language in 1972.  By the time she was 5 years old, she knew over 200 signs.  Koko was taught by Penny Patterson, who would speak to her while signing at the same time.  This enabled Koko to understand spoken English as well as she understood sign language.

As of 2012, Koko knows more than 1,000 signs and understands about 2,000 spoken English words.

A gorilla named Michael, who lived with Koko for a while, also developed significant signing ability.

An orangutan named Chantek, who was born in 1997, has learned about 150 signs in American Sign Language.

Kanzi, a bonobo, was the first non-human great ape to acquire language skills spontaneously.

He was the adopted son of a bonobo named Matata. In 1981, when Kanzi was 9 months old, Sue Savage-Rumbaugh tried to teach language to Matata, using lexigrams.

Kanzi was left to play around in the lab because he was thought to be too young for language training.

Amazingly, when Kanzi was separated from his mother for a short time, because she had been sent away for breeding, Kanzi began using lexigrams on his own. He went to the keyboard to try to communicate with Savage-Rumbaugh, asking her for food and to help him find his mother. On the first day of his separation from his mother, Kanzi went to the keyboard over 300 times.

Kanzi also showed an understanding of spoken English - which Matata had never developed. Kanzi seemed to find it easier to learn signs than his adoptive mother did.

When he was older, Kanzi was exposed to videos of Koko using sign language and picked up some sign language on his own.

Kanzi's younger half-sister, Panbanisha, also spontaneously began to use lexigrams. She began using the keyboard at an even younger age than Kanzi did. The two bonobos use language to communicate with each other.

Kanzi and Panbanisha also developed the ability to manufacture stone tools.