This is a reading comprehension exercise for children. It is written by Susan Fineman, a reading specialist in the New Haven, Conn., school district and based on an Associated Press story.
Some orangutan parents teach their offspring to use leaves as napkins. Others say good night with a spluttering, juicy raspberry. Still others get water from a hole by dipping a branch and then licking the leaves.
These examples, researchers say, prove the orangutan is a cultured ape, able to learn new living habits and to pass them along to the next generation.
The discovery, reported in a study appearing in the journal Science, suggests that early primates, which include the ancestors of humans, may have developed the ability to invent new behaviors, such as tool use, as early as 14 million years ago. That would be some 6 million years earlier than once believed.
"If the orangutans have culture, then it tells us that the capacity to develop culture is very ancient," said Birute Galdikas, a co-author of the study.
In the march of evolution, "orangutans separated from our ancestors and from the African apes many millions of years ago," she said. The study suggests they may have had culture before they separated, she said.
Orangutan culture, although crude by human standards, is culture nonetheless. It developed and is practiced independently by different groups and succeeding generations in the same way that human societies develop and perpetuate unique forms of music, architecture, language, clothing and art.
Galdikas, a researcher at the Orangutan Foundation International, and eight other international primate scientists analyzed years of observations of the shy Southeast Asian orangutan. They concluded that the ape definitely has the ability to adopt and pass along learned behaviors.
For instance, members of bands in Borneo and Sumatra make a kiss-squeak noise by compressing the lips and drawing in air. Both groups used leaves to amplify the noise, but only members of the Borneo group had discovered they could change the sound by cupping the hands over the mouth. The sounds are apparently used for communicating socially.
The opposite of the kiss-squeak is the raspberry -- breath is blown out through compressed lips to make a splattering sound. Only one of the six groups does this habitually, and it seems to be related to a bedtime ritual, Galdikas said.
A group in Sumatra has learned to use leaves as gloves when handling spiny fruits. A second Sumatran band has learned the unique skill of getting a drink by dipping a leafy branch into a water-filled tree hole and then licking the moisture from the leaves.
Galdikas said a group in Borneo routinely will force a small tree to the ground, riding it as it falls, and then grab nearby forest limbs before crashing to the ground. A group in Sumatra uses the same technique as a defensive maneuver, pushing over tree snags when they feel threatened.
Only one group of the six has discovered how to use sticks to extract insects from tree holes or to wedge out seeds from fruits. Such tool use is common among chimpanzees, but the Sumatran orangutan band puts a unique twist on the practice: They grip the stick with their teeth instead of their hands.
The dainty use of a napkin has been discovered in one band. Apes in Borneo routinely wipe their faces with leaves, and parents teach the social skill to their young.
Altogether, the researchers found 24 examples of behaviors that are routinely practiced by at least one of the groups and passed along to new generations. Twelve other behaviors, such as making a pillow with twigs, were seen only rarely or were practiced by a single individual.