Thursday, October 17, 2002


We're still learning from chimps

Each time we make a discovery about chimpanzees' behavior, researchers realize there are yet more questions to answer.

"We are never going to finish studying chimpanzees," says Elizabeth Vinson Lonsdorf, a doctoral candidate and researcher at Jane Goodall Institute's Center for Primate Studies at the University of Minnesota.

Since we are unable to go back in time to conduct behavioral studies on our ancestors, we study the animal we consider most closely related to us, she says.

"Chimps are not born knowing everything they need to know to survive," Lonsdorf says. "They learn from their parents. If we want to see how human behaviors developed, we can learn so much by studying them."

• Chimpanzees are found in 21 African countries. At the beginning of the 20th century, there were nearly 2 million on the continent; today, there are about 150,000.

• Biologically, chimpanzees are more closely related to humans than they are to gorillas.

• In the wild, chimpanzees live up to 50 years and in captivity somewhat longer.

• At birth, a chimpanzee weighs 2 to 4 pounds. An average adult weighs between 90 and 115 pounds and is 4 feet tall.

• Chimpanzees have longer arms than legs, enabling them to reach for fruits growing on thin branches that would not support their weight. They primarily like to eat fruits, buds, seeds, blossoms, insects and small mammals.

• Like human babies, infant chimpanzees rely on affectionate physical contact for healthy development and are dependent upon their mothers until age 7.

•Grooming is one of the most important social behaviors in chimpanzee communities and helps chimpanzees maintain or even improve their relationships.

• Chimpanzees are able to demonstrate joy and sadness, fear and despair, love and empathy and, sometimes, anger through violence. Primatologist Jane Goodall was among the first to observe wars between chimpanzee groups.

• Chimpanzees do not communicate with speech, but some have been able to learn more than 300 signs in American Sign Language while living in captivity.