One hundred years ago, there were approximately five million chimpanzees living on the African continent. Since then, free-living chimpanzee populations have been decimated as humans have destroyed African tropical forests, hunted the chimpanzees for food, and captured thousands of chimpanzees for sale to American and European laboratories, circuses, and zoos. Today, the chimpanzee is an endangered species, and scientists estimate that there are only between 80,000 and 130,000 chimpanzees left in the entire world.
Chimpanzees are not monkeys. The chimpanzee is humankind's closest living relative and a member of the great ape family, along with bonobos, gorillas and orangutans. Chimpanzees and humans are "sibling species"-- two species that are virtually identical in their genetic makeup. Chimpanzees share 98.76% of human DNA.
Free-living chimpanzees are indigenous only to Africa, can have a life-span of more than 50 years, and can weigh up to 200 pounds in captivity. Chimpanzees have demonstrated cooperative problem-solving, the representational use of numbers, and the ability to comprehend and use American Sign Language and artificial languages.
As with humans, the mother-infant bond among chimpanzees is extremely close. The chimpanzee mother nurses her infant for four to five years. The growing chimpanzee child then spends a prolonged childhood, until age ten or eleven, living with his or her family.
Free-living chimpanzees make and use a variety of tools for gathering and preparing food. For example, the chimpanzees of West Africa practice a stone tool culture. Their hammers and anvils, used to crack hard nuts, are similar to the tools of our own hominid ancestors.
Chimpanzees seek out and use certain plants medicinally to treat symptoms of various illnesses. Scientists following chimpanzees in the rainforest have been led to a variety of formerly unknown plant species that have pharmaceutical uses ranging from antibiotics to antiviral agents.
Washoe, the subject of Next of Kin, was one of NASA's "space chimpanzees." In the late 1950s, the U.S. Air Force captured more than 100 chimpanzees in the African jungle and began using them to test the effects of space flight. These space chimpanzees--or chimponauts--were made famous by Ham, the first chimpanzee in space (January 1961) and Enos, the chimpanzee who orbited the earth (November 1961) in advance of John Glenn. Later the Air Force abandoned Ham, Enos, and others to biomedical research.
There are approximately 1,400 chimpanzees available as biomedical research subjects living in the United States. Scientists have used them to test everything from lethal pesticides to cancer-causing industrial solvents, from yellow fever to HIV.
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Q. How do the chimpanzees use ASL?
A. Under double-blind conditions, we have found that the chimpanzees communicate information in American Sign Language (ASL) to human observers. They use signs to refer to natural language categories: e.g. DOG for any dog, FLOWER for any flower, SHOE for any shoe, etc. The chimpanzees acquire and spontaneously use their signs to communicate with humans and each other about the normal course of surrounding events. They have demonstrated an ability to invent new signs or combine signs to metaphorically label a novel item, for example: calling a radish CRY HURT FOOD or referring to a watermelon as a DRINK FRUIT. In a double-blind condition, the chimpanzees can comprehend and produce novel prepositional phrases, understand vocal English words, translate words into their ASL glosses and even transmit their signing skills to the next generation without human intervention. Their play behavior has demonstrated that they use the same types of imaginary play as humans. It has also been demonstrated that they carry on chimpanzee-to-chimpanzee conversation and sign to themselves when alone. Conversational research shows the chimpanzees initiate and maintain conversations in ways that are like humans. The chimpanzees can repair a conversation if there is misunderstanding. They will also sign to themselves when alone and we have even observed them to sign in their sleep.
Q. What are some specific directions for future research?
A. One of our long-term research focuses is developing and evaluating enrichment methods. Enrichment serves to make life interesting for this family of chimpanzees and potentially help other captive chimpanzees as well. With regard to communication we have another long-term project that is studying gestural dialects used by this family of chimpanzees and free-living chimpanzees in Africa. In addition we still examine these chimpanzees' use of ASL with humans and each other.
Check out the current research projects page for a more complete list of projects.
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Q. Does anyone ever go into the enclosure with the chimpanzees?
A. NO! No one is allowed inside the enclosure with the chimpanzees. Humans and chimpanzees do not make good physical companions. Chimpanzees are not only five-to-seven times stronger than humans (eight-to-ten times stronger in their upper bodies alone), they also have denser bones and thicker skin. In all types of interactions, chimpanzees must restrain themselves to avoid hurting humans. In play, chimpanzees regularly throw, slap and playbite each other. These actions elicit laughter among chimpanzees but humans would be hurt. If there was only one chimpanzee and no companions our role would be different; we would provide social interactions without touching or going into the enclosure. However, these chimpanzees always have each other for play, grooming or snuggling. Their bond with one another is very strong and separation is very stressful. The chimpanzees' human companions do interact through the wire mesh when the chimpanzees solicit tickling, chase games, grooming or other contact -- without ever putting their fingers or hands into the chimpanzees' enclosures.
Q. Is chimpanzee behavior in captivity the same as the behavior of free-living chimpanzees in Africa?
A. Many of the communicative behaviors used by these chimpanzees are the same as those used by chimpanzees in Africa. There are cultural differences between communities in Africa which include different customs, gestures and use of resources. These chimpanzees were raised in a unique cross-cultural environment among humans. Signing, wearing clothes and drawing are a few of the behaviors which these chimpanzees practice that free-living chimpanzees may not.
Q. How do the chimpanzees react to visitors?
A. Each chimpanzee reacts differently to visitors and the reaction of each chimpanzee changes from day to day. At times, they appear interested in the visitors and may come to the window to sign and interact. At other times, they may be resting or interacting with each other. Much like humans, they are not always ready for guests. We have found that limiting the length of observation time helps reduce the chimpanzees' stress level.
Q. Why do these chimpanzees require this much space?
A. Free-living chimpanzees typically live and move in home ranges that vary in size from 10- to 24-square kilometers, and may travel as much as one- to five-square kilometers a day. They build their nests and climb up to 80 feet above the ground and also spend time traveling and climbing in the overhead canopy. Because of this, it is important that the chimpanzee areas in the building are complex, have vertical space, and allow for some freedom of movement. Just like humans, chimpanzees need to exercise and require a complex environment to promote good physical and mental health. Compared to the ranges free-living chimpanzees have, the area available to these chimpanzees is severely limited.
Q. How old are these chimpanzees?
The chimpanzees living at CHCI are all adults:
- Washoe was probably born in September of 1965, celebrates her birthday on June 21st - the "Project Washoe" anniversary. Washoe died at CHCI on October 30, 2007.
- Tatu was born on December 30, 1975.
- Dar was born on August 2, 1976.
- Loulis was born on May 10, 1978.
- Moja was born on November 18, 1972. Moja died at CHCI on June 6, 2002.
Q. What are their family relationships?
A. Dar and Loulis (males) relate to Tatu (female) as brothers to a sister.
Q. Will these chimpanzees have offspring?
A. No. In free-living chimpanzees Jane Goodall has observed incest taboos. Mothers do not allow their sons to copulate with them, sisters do not copulate with their brothers and females do not copulate with older males in their familial group. Though none of these chimpanzees are biologically related, they have grown up in this family group and show no sexual behavior toward one another. If they did show sexual interest, we would have Dar and Loulis vasectomized.
Q. How did the chimpanzees acquire their signs?
A. Washoe was raised as if she were a deaf child by Beatrix and Allen Gardner at the University of Nevada in Reno from 1966 to 1970. Roger Fouts joined the project as a graduate student in 1967. Washoe, acquired at the age of 10 months, was immediately immersed in American Sign Language with a socially enriched environment where she soon learned to use ASL in daily interactions with her human companions. Moja, Dar and Tatu were immersed in ASL in a similar fashion. In 1979, Loulis, the adopted son of Washoe, was the focus of "Project Loulis," designed by Roger and Deborah Fouts to examine if an infant chimpanzee would acquire signs from his mother. Humans were prohibited from signing around Loulis until 1984, when it had been verified that he had acquired his signs from his mother and the other chimpanzees.
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Chimpanzees and HIV
Q. Do Chimpanzees get HIV and AIDS?
A. Chimpanzees resist the AIDS symptoms, and some of them even reject the virus. This means that they have been exposed to the virus for a long time (Hahn's recent findings) and have developed a genetic immunity to it. They can become HIV positive, but never develop symptoms of AIDS.
Q. Do Chimpanzees make good subjects for HIV/AIDS research?
A. Given the natural protection their species has developed, they would make terrible subjects on which to test a vaccine. If you inject a chimpanzee with a vaccine you will not know whether the vaccine protected them or it was their own natural immunity. You will get "false positives" and run the risk of testing useless vaccines on humans.
Q. Given that Chimpanzees are our genetic "Next of Kin" shouldn't more research be done?
A. This new information should be used to stop all biomedical research for ethical reasons. Likewise using an endangered species to help an overpopulated species become more overpopulated doesn't make rational sense.
Q. How could people get HIV/AIDS from Chimpanzees?
A. You cannot get HIV from just anyone, chimpanzee or human. You can only get HIV from a human or Chimpanzee who has been infected with HIV. Having an immunity to a virus is not the same as being infected with it. The so-called bushmeat trade could be a potential transmission vector to spread a virus, which is benign to its host species, but lethal for humans. The bushmeat trade must be discouraged as a health risk.
Q. What are the ethical implications of HIV/AIDS testing and research on Chimpanzees?
A. New evidence indicates that the technology and the communication of the chimpanzee community meets the definition of culture. We also know that chimpanzee's cognitive capacities are very similar to our own, both intellectually and emotionally. By any reasonable definition chimpanzees should be categorized as a people. For these reasons it would be unethical to do invasive research on captive or free-living individuals if the same standards and protections are not used for human experimentation are not used with chimpanzees.
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Chimpanzees and the Law
Should Chimpanzees and other Great Apes be granted legal protection?
With our three decades of experience studying the communication of chimpanzees, we have become more aware than most that these creatures share many morally significant traits with humans and that this should entitle them to an appropriate level of legal protection.
How can legal rights be obtained for Great Apes?
We believe the New Zealand Animal Welfare Bill (AWB) offers an excellent opportunity to do this and thus show the world, including the United States, how to bring enlightened legislation into line with our new empirical knowledge of the chimpanzee mind.
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Q. In what ways are chimpanzees endangered?
A. Chimpanzee populations once spanned equatorial Africa from the western coast to Tanzania. Today there between 80,000 and 130,000 chimpanzees in the world. The human species is responsible for this decline. Logging companies and agriculture are wiping out large areas of the rain forest and destroying the chimpanzees' habitat. (In Sierra Leone, 97 percent of the rain forest habitat has been destroyed.) An additional threat is the international market where young chimpanzees are captured and sold to laboratories, zoos, circuses, and private owners around the world. A new and greater threat has recently developed for the free-living chimpanzees -- the bushmeat trade. Eating bushmeat has become popular among city dwellers, and as a result has created yet another pressure on free-living chimpanzees. To learn more about the bushmeat trade we recommend reading "Eating Apes" by Dale Peterson.
Q. What can be done to help preserve chimpanzees?
A. Jane Goodall and the Chimpanzee Collaboratory cite important changes that are needed to help chimpanzees. We must preserve their habitat in Africa and eliminate the demand for chimpanzees by both abolishing their use in biomedical research and prohibiting the use of chimpanzees in entertainment where they are often abused and degraded. We must also prohibit private ownership of chimpanzees. A baby chimpanzee often starts as a loved family member, but as an adolescent may be locked in a cage or shipped to a research facility when the owners can no longer care for him or her. By increasing our understanding of chimpanzees, we can help to save them