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[Josh Greenman <josh.greenman AT gmail.com>]

http://www.nytimes.com/2005/11/15/science/15conv.html?8hpib

November 15, 2005

Revealing Behavior in 'Orangutan Heaven and Human Hell'

By CONNIE ROGERS

People keep asking Carel van Schaik if there is anything left to
discover in fieldwork.

"I tell them, 'A lot,' " said Dr. van Schaik, the Dutch primatologist.
"Look at gorillas. We've been studying them for decades, and we just
now have discovered that they use tools. The same is true for
orangutans."

In 1992, when Dr. van Schaik began his research in Suaq, a swamp
forest in northern Sumatra, orangutans were believed to be the only
great ape that lived a largely solitary life foraging for hard-to-find
fruit thinly distributed over a large area.

Researchers thought they were slow-moving creatures - some even called
them boring - that didn't have time to do much but eat.

But the orangutans Dr. van Schaik found in Suaq turned all that on its
head. More than 100 were gathered together doing things the
researchers had never seen in the wild.

Dr. van Schaik worked there for seven years and came to the radical
conclusion that orangutans were "every bit as sociable, as technically
adept and as culturally capable" as chimpanzees.

His new conclusions about how apes - and humans - got to be so smart
are detailed in his latest book, "Among Orangutans: Red Apes and the
Rise of Human Culture."

Now a professor of anthropology at the University of Zurich and the
director of its Anthropological Institute and Museum, Dr. van Schaik
discussed his findings in a recent telephone interview from his office
there.

Q. What were you looking for in the Suaq swamp?

A. We'd been working in a mountainous area in northern Sumatra, and it
felt as if we were missing the full picture of orangutan social
organization. All higher primates - all of them - live in distinct
social units except for the orangutan. That's a strong anomaly, and I
wanted to solve it.

Q. How was Suaq different from other orangutan habitats?

A. It was an extraordinarily productive swamp forest with by far the
highest density of orangutans - over twice the record number. The
animals were the most sociable we'd ever seen: they hang out together,
they're nice to each other, they even share food.

Q. But you almost left this orangutan habitat after a year?

A. We'd never worked in a place like this, and it was exhausting. To
get into the swamp where they were we would wade through water -
sometimes chest deep, two hours in, two hours out every day. There
were countless species of mosquitoes.

It was what I call orangutan heaven and human hell. But then someone
noticed that they were poking sticks into tree holes. It sounded like
tool use, so we decided to build boardwalks in the swamp, and things
got a lot easier.

Q. Were orangutans using tools?

A. It turned out Suaq had an amazing repertoire of tool use. They
shape sticks to get at honey and insects. Then they pick another kind
of stick to go after the scrumptious fat-packed seeds of the neesia
fruit. One of them figured out that you could unleash the seeds with a
stick and that was a big improvement in their diet.

Lean times are rare at Suaq, not only because the forest is
productive, but because the orangutans can get to so much more food by
using tools. So they can afford to be more sociable.

Q. How did you discover that the tool use is socially transmitted?

A. Well, one way to prove it is to see if the orangutans use tools
everywhere the neesia tree exists. This was in the late 90's. Swamps
were being clear-cut and drained everywhere, and the civil war in Aceh
was spreading.

 I felt like an anthropologist trying to document a vanishing tribe.
It turned out that in the big swamps on one side of a river, the
orangutans do use tools, and in the small swamp on the other side,
they don't. Neesia trees and orangutans exist in both places. But the
animals can't cross the river, so the knowledge hadn't spread. At that
point, the penny dropped and I realized their tool use was cultural.

Q. So your discovery that the orangutans learned tool use from one
another explains "the rise of human culture" part of your book's
subtitle?

A. Well, yes. Orangutans split off from the African lineage some 14
million years ago. If both chimps and orangutans make tools, our
common great ape ancestor probably had the capacity for culture.

Q. I always thought we got smart after we came down from the trees.

A. Actually orangutans are the largest arboreal mammal and have no
predators up in the trees so they live a very long time - up to 60
years in the wild - and have the slowest life history of any nonhuman
mammal including elephants and whales.

A slow life history is key to growing a large brain. The other key to
intelligence is sociability.

Q. Were orangutans more social in the past?

A. I guess the rich forest areas that allowed them to live in groups
were much more common in the past - they're the ones that are best for
rice growing and farming - but there's no way of knowing for sure.

Q. If social inputs make you smarter, why aren't monkeys cleverer?

A. One thing we know is that being close to others isn't enough.
Highly tolerant sociability is important - that you can be relaxed
next to others. You need to be able to focus on what your neighbor is
doing and not worry about whether he is going to sneak something or
beat up on you.

It's that kind of social tolerance that is common to all great apes.
It's rare in monkeys - except cebus monkeys; they're tool users,
long-lived and socially very tolerant.

Q. You end your book with a bleak picture of the future of orangutans
because of habitat conversion and illegal logging. Since then there's
been a devastating tsunami and people need to cut down even more trees
to put roofs over their heads. What does the future look like now?

A. One way to help people in Sumatra would be to donate wood on a
large scale. But things may be better in Borneo.

There's a new Indonesian president, and in the last few months it
looks as if the government is serious about cracking down on illegal
logging. That leaves me more hopeful.