Big-brained birds survive better in nature

January 10, 2007

Birds with brains that are large in relation to their body size have a lower mortality rate than those with smaller brains, according to new research published in the journal Proceedings of the Royal Society B: Biological Sciences today.

The research provides the first evidence for what scientists describe as the 'cognitive buffer' hypothesis - the idea that having a large brain enables animals to have more flexible behaviours and survive environmental challenges.

This theory was first put forward to answer the puzzle surrounding why animals, including humans, would evolve a larger brain, given the 'cost' associated with developing and maintaining a larger brain.

The researchers compared the brain size, body mass and mortality rates in over 200 different species of birds from polar, temperate and tropical regions.

They found that birds with larger brains relative to their body size survived better in nature than birds with small brains. This may explain why, for example, birds with small relative brain sizes, such as pheasants, find it harder to avoid a moving car than those with larger brain size, such as magpies.

"The idea that large brains are associated with reduced mortality has never been scientifically tested," said Dr Tamas Szekely from the Department of Biology & Biochemistry at the University of Bath.

"Birds are ideally suited for such a test, as they are one of the only groups of animals for which the relationship between large brains and enhanced behavioural response to ecological challenges is best understood.

"We have shown that species with larger brains relative to their body size experience lower mortality than species with smaller brains, supporting the general importance of the cognitive buffer hypothesis in the evolution of large brains."

The researchers made allowances for factors which may have accounted for variations in mortality rates, such as migratory behaviour, competition for mates and chick behaviour.

"Our findings suggest that large-brained animals might be better prepared to cope with environmental challenges such as climate change and habitat destruction," said Dr Szekely, who worked with researchers from the Autonomous University of Barcelona (Spain), Pannon University (Hungary) and McGill University (Canada) on the project.

"This is supported by other research which has shown that large-brained birds are more successful in colonising new regions and are better at surviving the changing seasons."

Source: University of Bath

Explore further: What the dog-fish and camel-bird can tell us about how our brains work

Related Stories

Chameleons' eyes are not so independent

July 8, 2015

Famed for their ability to change colour, chameleons have yet another mind-boggling talent: their eyes appear to swivel completely independently. This means that they can simultaneously track two completely different views ...

'Map of life' predicts ET. (So where is he?)

July 2, 2015

Extra-terrestrials that resemble humans should have evolved on other, Earth-like planets, making it increasingly paradoxical that we still appear to be alone in the universe, the author of a new study on convergent evolution ...

Recommended for you

Researchers design first artificial ribosome

July 29, 2015

Researchers at the University of Illinois at Chicago and Northwestern University have engineered a tethered ribosome that works nearly as well as the authentic cellular component, or organelle, that produces all the proteins ...

Meet the high-performance single-molecule diode

July 29, 2015

A team of researchers from Berkeley Lab and Columbia University has passed a major milestone in molecular electronics with the creation of the world's highest-performance single-molecule diode. Working at Berkeley Lab's Molecular ...

Researchers build bacteria's photosynthetic engine

July 29, 2015

Nearly all life on Earth depends on photosynthesis, the conversion of light energy into chemical energy. Oxygen-producing plants and cyanobacteria perfected this process 2.7 billion years ago. But the first photosynthetic ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.