May 17, 2006

Monkeys use sound sequence to convey command

LONDON (Reuters) - It could be mistaken for meaningless
jabbering or sound effects from an action comic strip but the
"pyow hack hack pyow hack hack" noises of some African monkeys
are a signal it is time to leave.

All animals make distinct sounds but male tree-dwelling,
putty-nosed monkeys in Nigeria can combine two noises in novel
ways to convey new meaning -- a trait that was thought to be
uniquely human.

"We found these monkeys make two different alarm calls but
in addition they combine the calls to convey to other group
members that the troop should move on," said Klaus Zuberbuhler,
a psychologist at the University of St Andrews in Scotland.

Dominant putty-nosed male monkeys release the "pyow" sound
when leopards are around and the "hack" to warn of approaching

Zuberbuhler's colleague Kate Arnold discovered the monkeys'
vocal talent while studying and recording how they reacted to
sounds of leopards and eagles.

After replaying the tapes, the researchers noticed the call
sequences the monkeys produced.

"Whenever they do the sequence, the troop moves on and
leaves. By combining these two alarm calls into a high order
sequence, they generate a third meaning that tells everyone it
is a good idea to move on," said Zuberbuhler, who reported the
findings in the journal Nature.

He added that songbirds are known to combine sounds in
structure sequences but it has not been linked to meaning or a
command to others.