September 29, 2005

Wild gorillas seen using tools for first time

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Two female gorillas have been
photographed using sticks as tools to get through swampy areas,
the first time the apes have been seen doing so in the wild,
researchers reported on Thursday.

"This is a truly astounding discovery," said Thomas Breuer
of the Wildlife Conservation Society and the Max Planck
Institute for Evolutionary Anthropology in Leipzig, Germany,
who led the study.

The findings can help shed light on how human beings came
to use tools, and also broaden the understanding of how animals
use them, the researchers said.

"Although there are reports of tool use by captive
gorillas, including object throwing and use of tools in
feeding, there has been to our knowledge no reported case of
tool use in by wild gorillas, despite decades of field
research," they wrote in their report, published in the Public
Library of Science Biology, an online journal.

All great apes use tools in captivity, but scientists have
worried this does not necessarily reflect natural behavior,
just something copied from humans.

"Tool usage in wild apes provides us with valuable insights
into the evolution of our own species and the abilities of
other species. Seeing it for the first time in gorillas is
important on many different levels."

They describe the two instances in the northern rain
forests of the Republic of Congo.

"We first observed an adult female gorilla using a branch
as a walking stick to test water deepness and to aid in her
attempt to cross a pool of water at Mbeli Bai, a swampy forest
clearing in northern Congo," Breuer and his international
colleagues wrote.

In the second case, they saw another pull up a dead shrub.

"She forcefully pushed it into the ground with both hands
and held the tool for support with her left hand over her head
for two minutes while dredging food with the other hand," they

"Efi then took the trunk with both hands and placed it on
the swampy ground in front of her, crossed bipedally on this
self-made bridge, and walked quadrupedally toward the middle of
the clearing."

Chimpanzees, closely related bonobos and other apes have
also been seen using tools in the wild -- for instance, to
catch termites. And other animals such as crows have been seen
using them. But never wild gorillas.

"Information on tool use and factors favoring tool use in
wild apes helps us to understand its importance in the
evolution of our own species," Breuer and his colleagues,
Mireille Ndoundou-Hockemba and Vicki Fishlock wrote.

The gorillas live in a protected area, and the researchers
said this was key.

"These protected areas are not only important for the
conservation of species they contain, they also hold the key to
comparing our own development as a species with our next of
kin," Breuer said in a statement.