Birds with bigger brains like crows and parrots survive better than
their dimmer feathered friends, according to a study published on
Wednesday.
Scientists have suspected that birds with large brains in relation to
their body size lived longer because they were able to adapt their
behaviour and cope with environmental challenges.
Now they have provided evidence that it does.
"We have tested the hypothesis that the brain can buffer animals against
the environment and help them to survive when they face environmental
challenges," said Dr Daniel Sol, of the Centre for Ecological Research
and Forestry Applications in Barcelona, Spain.
After comparing mortality rates, brain size and body mass of 236 species
of birds from different regions of the world, Sol and scientists in
Britain, Hungary and Canada discovered that the bigger the brain the
better.
"We have found that species that have the larger brains are the ones
that survive better, suggesting that the brain has helped them to
survive. That's the main finding of this work," Sol told Reuters.
Crows, ravens and parrots have the largest brains while pheasants have a
relatively small brain.
Earlier studies have shown there is a relationship between the size of
the brain and an animal's capacity to create new behaviours and adapt
more easily.
Studies of primates have produced similar findings.
"The idea is that if you have a big brain you are more capable of
adjusting behaviour and responding to environmental changes. This can
help you to survive," said Sol, who reported the finding in the journal
Proceedings of the Royal Society B: Biological Sciences.
Big-brained birds are also better at colonising new regions and coping
with changing seasons.
Dr Tamas Szekely, of the University of Bath in England and a co-author
of the report, said birds were ideal to test the hypothesis because they
are the only species in which brain size and behavioural response to
environmental challenges is understood.
"Our findings suggest that large-brained animals might be better
prepared to cope with environmental challenges such as climate change
and habitat destruction," Szekely said.
(Por Patricia Reaney,
Planet Ark, 11/01/2007)