How did the chimpanzee cross the road?
* 14 September 2006
* From New Scientist Print Edition. Subscribe and get 4 free
Cautiously, it would seem. When it comes to crossing roads,
chimps seem to have formulated their own version of a highway
code. What's more, the time they spend pondering a strategy
before crossing depends on how dangerous the road is.
When some monkeys and baboons cross risky terrain, adult
males travel at the front of the group to reduce the risk of it
being attacked by predators. This had never been recorded in
great apes, but now Kimberly Hockings of the University of
Stirling in the UK and her team have found that chimps display a
similar behaviour when crossing roads that carve through the
forests in which they live and forage.
She has found that adult males in the group of 12 chimps she
studies in Bossou, Guinea, take up the front and rear position
as the group crosses roads in single file, while more vulnerable
females and juveniles occupy the less exposed centre of the
group. During the 28 crossings she observed, the position of the
alpha and other dominant males changed depending on the
perceived risks. In some cases, adult males stood guard -
lollipop-lady or crossing-guard style - waiting for the group of
chimps to make it across (Current Biology, vol 16, p R668).
This suggests they may cooperate to decide on the safest
strategy, says Hockings. "Road crossing is just one of
chimpanzees' many adaptations to a human-dominated
environment," she says, and "may be a sort of culture
passed down through generations."
From issue 2569 of New Scientist magazine, 14 September 2006,