Study reveals complex orangutan culture

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http://www.cnn.com/2003/TECH/science/01/02/coolsc.orangutans/index.html

 

Study reveals complex orangutan culture

By Marsha Walton

CNN Thursday, January 2, 2003 Posted: 5:18 PM EST

(2218 GMT)

 

Remember how the television show " The Waltons " used to

end each evening: Good night, John Boy. Good night,

Mary Ellen. Good night, Grandpa. In orangutan culture,

there's a little less formal way to say good night:

Ppppffffffffttttttttt.

 

It's the spluttering " raspberry " sound that humans use

in jest or sarcasm.

 

Researchers say this vocalization, plus more than two

dozen other signals and skills observed in wild

orangutans, provide evidence that these great apes

show cultural variations. Their culture, described as

geographically distinct behaviors, comes from

observing and mimicking their peers. It goes above and

beyond what's instinctive, and what they learn from

their mothers.

 

So who do young orangutans look to for role models in

gaining this playful and productive know-how?

 

" Those who have the most skills are the coolest, " said

Carel van Schaik, professor of biological anthropology

at Duke University in Durham, North Carolina. His

research is published in this week's Science magazine.

Many of the skills involved access to food and water,

and comfort.

 

Van Schaik and colleagues studied six different wild

orangutan populations on the islands of Sumatra and

Borneo in Southeastern Asia. While the socially

transmitted behaviors were often similar, there were

geographic variations. That, say researchers, shows

that distinct great ape cultures exist, and may have

been around for at least 14 million years.

 

" We used to think culture was something specific just

to humans and chimps, going back just six or seven

million years, " he said. Chimp culture was first

documented in the 1980s.

 

For example, a " kiss squeak " is a common orangutan

signal. It is just like it sounds, the same

exaggerated kiss sound a human might make to a child

or in jest to a loved one. Van Schaik said the kiss

squeak is used by orangutans when there is something

near them that they don't like, such as a predator or

perhaps an intrusive human being.

 

" What we didn't know was how this signal varied, " said

Cheryl Knott of Harvard University, co-author of the

study.

 

" For example, at the site of Gunung Palung in Borneo,

orangutans almost always grab a handful of leaves and

produce the sound by kissing into the leaves. At other

sites they may use their fist, a flat hand, or nothing

at all to amplify the sound. We had no idea of this

fascinating variety, " she said.

 

Sometimes it's even more elaborate, van Schaik said.

Some orangutans would pull off a bunch of leaves from

a branch, fling their arms in a theatrical gesture,

toss the leaves and let them rain down to draw as much

attention to themselves as possible.

 

" That way they made the intruder even more aware that

they were annoyed, " said van Schaik.

 

Yet these practices were never observed in Sumatra.

The practices common in one group and absent in

another are of great interest to researchers.

 

Ready to play, or mate

 

Scientists also discovered that the same gestures

sometimes had different meanings in different ape

populations. Tearing a leaf along the mid-rib makes a

nice shearing sound, van Schaik said. In one group,

that action means " I'm ready to mate, " while in

another it means " I'm ready to play. " An important

distinction in any species culture!

 

While some of the behaviors are playful, others are

critical to survival.

 

" Natural selection has favored the ability to have

culture, because many of these actions have to do with

skills, " said van Schaik.

 

For example, animals that don't use tools may not have

access to the best food. Therefore, the " culture of

copying " animals with an inventive spark isn't just

for copying sake. The animal learns there's often a

payoff as well: a long stick can relieve a hard- to-

reach itch; a curled leaf can reach water in an out of

the way place.

 

From the day they are born, orangutans will " suck up

information from anyone who comes close, " said van

Schaik. Youngsters spend seven or eight years in close

relationships with their mothers, then another four or

five associating more with juvenile peers and other

orangutans before they are sexually mature adults.

 

So how do chimp and orangutan cultures differ from

humans? Human culture is cumulative; great ape culture

is not. Knowledge and behavior are not passed on from

one generation to the next.

 

" I use a phone and a computer every day, taking

advantage of what humans before me created, " said van

Schaik. " I could not have created those tools on my

own, " he said.

 

On tap for further research will be tests for just

that type of cultural innovation. Van Schaik would

like to look at how simple behaviors evolve into the

complex traditions that distinguish human beings from

ape ancestors.

 

Orangutan researchers are warning of threats to any

further study of these primates in the wild. Logging,

mining, hunting, and forest fires threaten the

animals. Their populations are dwindling throughout

their range in Indonesia and Malaysia.

 

" This is our last chance, " said van Schaik. " You

cannot recreate cultures. " He said a stepped up

collaboration between researchers and habitat

conservation efforts can prevent further destruction.

 

 

 

 

 

 

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