Koko is probably the world's most famous gorilla. Born in 1971 at a San Francisco zoo, she is a female lowland gorilla. Koko's claim to fame is that she has been the subject of the longest continuous inter-species communication project ever.

What began as a four-year postgraduate project for Dr Francine 'Penny' Patterson has turned into her life's work. If her research is to be taken at face value, it is the most amazing story of inter-species communication since Dr Dolittle.

Koko was known as Hanabi-Ko¹ when she was first introduced to Penny, and at just a year old she was sickly and undernourished. She was perfect for the project Penny had planned - to attempt communication by sign language with one of humankind's closest relatives.

Penny decided at the outset that she wouldn't attempt to teach Koko to verbalise and instead would teach her American Sign Language. This method of communication had been used with a certain amount of success since the 1930s with chimpanzees and gorillas. With permission from the zoo, Project Koko was soon underway and, within a few weeks Koko had learned to sign for food and drink using the correct American Sign Language gestures. However, her large hands meant that her signs were clumsy and the gestures were soon amended to what has been named Gorilla Sign Language.

What do You Say to a Gorilla?

Initially, all Penny's efforts were in teaching Koko the basic signs and of course in recording her responses to standard tests, but it soon became apparent that Koko wanted her own input into the experiment. Completely spontaneously, Koko began to string the signs together and add her own signs to the 'conversations'. For example, Koko was not taught the sign for ring; however she made her own sign by combining the signs for finger and bracelet therefore quite logically a ring is a finger bracelet. For females she signs 'lips' and for men she signs 'foot'.

After some time, Koko expressed to her caregivers that she was lonesome, and a friend was found for her: Michael, another lowland gorilla. Michael was born in Cameroon, Africa and orphaned by poachers². He arrived at the project in 1976, via Vienna and it was hoped that if the pair were compatible, they would eventually mate when they reached maturity.

After a bit of a bumpy start the gorillas became firm friends, and while no plans were made in the first instance to teach Michael to sign, it soon became apparent that he was a willing student. Michael knew over 20 signs by the end of his first year with the project. The most amazing aspect of it was that he was taught some of the signs by Koko, and the pair - without encouragement - even began signing to each other.

What Would a Gorilla Say to You?

Female gorillas reach sexual maturity at around the age of ten and when Koko was 12 years old she expressed a wish to have a baby. It was signed to her that she should perhaps consider Michael as a father for any offspring and her reaction was surprising. She expressed a human-like 'embarrassment' by the suggestion. Following some further questioning, she revealed that since they had been raised together they were like siblings and she considered Michael her brother. Their mating was therefore unacceptable in gorilla society.

Astounding as this seems, gorillas appear to have their own rules regarding suitable matches, and for this reason Koko and Michael were destined to remain just good friends.

Since the project had badly misinterpreted the relationship between Michael and Koko, she was offered an early birthday present in an attempt to cheer her up. Dr Patterson was shocked when she requested a kitten. From a basket of abandoned kittens, Koko selected a tailless Manx cat and called it All Ball. Koko cared for All Ball like a real gorilla baby, even letting him suckle for comfort. In December that same year, All Ball left the gorilla enclosure and was hit by a car. The result of this untimely accident was another display of human-like emotion. Koko expressed grief at the loss of All Ball: it was reported that she signed 'sad' and 'cry' when told of All Ball's death and wailed and cried for two days.

Koko has since had two other Manx cats as pets which makes her unique yet again in being one of the few non-humans to keep a pet.

Additional Speech

As well as signing her unique version of American Sign Language, Koko has learned to use a computer to give herself an actual voice. She has a specially-adapted Mac II gorilla-proof computer and screen³ on which she can make her own sentences. These are spoken by a voice she chose for herself from a selection. It also enables her to have limited control over her environment: she can, for instance, have the lights on when she wants.

The DVD A Conversation With Koko is available, and shows the path of the research and depth of the relationship between Dr Patterson and Koko. It is also worth noting that Koko was the acknowledged inspiration for Amy the talking gorilla in Michael Crichton's Congo.

Koko has appeared twice on the cover of National Geographic⁴ and once on the cover of the New York Times magazine. She has also made guest appearances on television shows and has generally been an ambassador for her species and for those involved in efforts to secure their future.

Another world first came in 1998 when Koko took part in the first ever inter-species live webchat with Dr Patterson on AOL.

Koko has many celebrity friends who have become involved with the project, including Sting and Robin Williams. In 2004, Koko and Robin Williams shared the spotlight in an advertising campaign to raise awareness of the plight of the great apes.

Relationships

In 1991 Ndume, a ten-year-old father of three, was selected by Koko from video footage in an attempt to find a suitable male to fulfil her desire for motherhood. This was part of a video dating programme designed to facilitate breeding of captive endangered species. Ndume has not participated in the language programme and is solely intended as a mate for Koko. To date, they have not displayed any mating behaviour but it is hoped they will manage the act before Koko reaches 40: after this time, her fertility will naturally decline.

In August, 2000, Michael died of heart failure, and naturally after 24 years of his company Koko was deeply upset. When told of his death she searched his rooms and cried. She searched their enclosure for him and signed his name repeatedly. Following his death, Koko was reluctant to be left alone, and by sign language she requested that a light be left on at night in her enclosure. At the time of his death, Michael could sign over 600 phrases and understand over 1,000 words spoken in English.

Michael's demise has changed the dynamic of the group; after many months of mourning, Ndume has assumed the role of alpha male and has become much closer to Koko, who in turn has become much more eager for Ndume's attention. It is thought that their failure to breed is due to the lack of other females. In the wild, gorillas would live in groups with many females and one dominant male. The Gorilla Foundation is currently planning to open the Maui Preserve, which intends to provide a suitable location in Hawaii to set up a breeding colony of lowland gorillas - including Koko and Ndume.

When Communication Matters

In 2005 Koko told her caregivers she was in pain and when the experts arrived in their droves she was able to indicate to them that she had toothache. When presented with a pain chart, she was able to indicate the level of her pain was between nine and ten. Needless to say if you're a vet it is very useful to have a 300lb gorilla tell you where it hurts and how badly. Under anaesthetic, the offending tooth was removed and the opportunity was taken to give Koko a full health check⁵. Thankfully, she was given a clean bill of health.

Other Opinions

Other species, including chimpanzees, have been involved in signing since the 1930s and while no study is as complete as that of Dr Patterson and Koko, the results appear to show that language is not the sole domain of the human species. Koko, while showing intelligence and reasoning in her communication, does, however, have the attention span of the average three-year-old and gets bored very quickly.

Some scientists claim that Dr Patterson is placing anthropomorphic behaviour on an animal which is just playing at signing for treats or rewards, and that no other species has the ability to communicate on a human level; however, the detractors are quick to accuse without reviewing all the evidence of this behaviour.

Dr Patterson and her associates have also been accused of being too emotionally involved with the research to form valid scientific conclusions, and of over-analysing the signs made by Koko. Taking this together with the fact that only her caregivers and Dr Patterson readily understand her 'lazy' signing, some scientists remain sceptical. This has, to some degree, been overcome by the fact that other signers can learn to understand Koko and her abbreviations relatively quickly. Given the very nature of sign language - facial expressions, demeanour and hand signs are all used to interpret meaning - it is understandable that science remains unconvinced.

Still, some 34 years later, Koko has a vocabulary of over 1000 signs, and can understand more than 2000 English words. She has an IQ of 70-75 (below the average human IQ of 100), but the tests are obviously designed for humans and therefore biased to measure human responses. For example, when asked where would she go to shelter from rain, Koko lost points by choosing the option 'under a tree' rather than the 'correct' option of 'into a house'.

The Future

Koko has persisted with her wish to have a baby and has even confirmed that should her wish be realised she would teach the baby to sign. It is hoped that the Maui Preserve will be completed in the near future and she can live her life out with Ndume, and any offspring, in its relative freedom. Given the right circumstances Koko could be expected to survive well into her 50s and if she were able to teach her offspring to sign, the hope is there for second-generation inter-species communication.