We can learn a lot from 'Pongo' family

We can learn a lot from 'Pongo' family

Just as Asia's only great ape faces its greatest crisis,
scientists have released important new findings on the species.

The latest research has found that the major differences in
appearance, behavior and genetics of orangutans in Sumatra and
Borneo warrant their reclassification as separate species -- the
Bornean Pongo pygmaeus and the Sumatran Pongo abellii.

Previously they were regarded as subspecies of the same
species.

"Sumatran orangutan females give birth, on average, once every
nine years, while females in eastern Borneo average six years,
with western Borneo females somewhere in between," said Carel van
Schaik, a professor of biological anthropology at Duke University
in the United States.

"The shorter birth-interval for eastern Borneo is probably as
a result of them having a slightly higher adult mortality. This
is probably due to the fact that orangutans in eastern Borneo
have harsher climatic conditions to deal with. They have less
fruit and long periods of time when there are only leaves to
eat," said Professor van Schaik.

"If you go into the leaf-eating business, there are risks that
you'll poison yourself," he added

As well, scientists now regard Bornean orangutans as forming
three separate subspecies, with distinct differences even within
subspecies in different areas.

"Within Borneo there are all these big rivers which separate
them and they are clearly separate populations. They are
biologically different, and what is more for me as an
anthropologist, is that we see all kinds of cultural differences
between orangutan populations."

One example is how different populations perform their "kiss-
squeak", the distress signal orangutans send to each other or to
a predator.

"As researchers recording orangutan behavior in the forest
canopy, we used to just write down 'kiss-squeak', but we've just
recently realized that in some places they kiss-squeak on the
flat of their hand, to enhance the sound, while in other places
they shape their hand like a trumpet and turn it as they squeak.

"In other places they kiss on leaves, but sometimes it's a
single leaf and sometimes they strip a whole bunch of leaves.
Then they stretch out their hand and rain the leaves down on you.

It enhances the message that this animal is not a happy puppy,
right?"

"Now this shows that the animals are incredibly 'copying-
oriented'. Like us, they have role models that they emulate and
they say 'OK this is how one does it here, I'll do it that way
too.'"

Professor van Schaik believes studying such behavioral
differences will help us understand the evolution of human
culture and intelligence.

"We are just another great ape, and yet we are so vastly
different from the others. What caused that? The best way to look
at that, because our ancestors are gone of course, is to look at
all the variability among the great apes we still have.

"What causes that variability, what brings all that out in the
great apes? (If we answer those questions) maybe we can
extrapolate from that toward humans. We might learn a lot about
our own history by studying the orangutans, but we need a lot of
populations. You can't study that in one population. So even if
by some miracle one population is saved in perpetuity, we will
still lose that opportunity to study our own past."

Professor van Schaik says the orangutan faces what he calls,
'the redwood problem', based on President Reagan's comment 'If
you've seen one redwood you've seen them all.'

"If you apply that to the orangutans you think - I've looked
at one orangutan, now I know them all. It turns out you don't
know them at all because orangutans show incredible variability
within and across their subspecies," said Professor van Schaik.

But these new classifications could soon be meaningless as
species and subspecies alike near extinction. There are fewer
than seven thousand Sumatran orangutan left, and the subspecies
in East Kalimantan, the black orangutan, has only a few
fragmented populations remaining.

"Just imagine that you have to tell children," said Professor
van Schaik, "'this is the orangutan, it used to live in these
forests. People sort of figured out what they did but they didn't
quite learn everything there was to learn before they went
extinct. And now you'll have to live in a world without them.'"

"If we let a species become extinct that's so intelligent, so
genetically close to us, so charismatic, then what do the
buffaloes have to hope for, what do the birds have to hope for?"
said Dr Willie Smits, Chairman of Borneo Orangutan Survival (BOS)
Foundation.

"And eventually that whole net is going to collapse - what do
we humans have to hope for ourselves? So the orangutan are a big
warning flag for what is so us to come."

-- Jacqueline Mackenzie