Birds with smaller brains less likely to survive

Subject: Birds with smaller brains less likely to survive
From: knightl <>
Date: Thu, 15 Sep 2005 18:53:42 +1000
G'day John,

I'm sure the Royal Society would benefit immensely from your wisdom and that the editor of the Proceedings would welcome your feedback. Could you please post the response you receive from the publisher?

Many thanks,

PS, here are the publication details to help you assemble your critique ...

Proceedings: Biological Sciences
ISSN: 0962-8452 (Paper) 1471-2954 (Online)
Issue: FirstCite Early Online Publishing
DOI: 10.1098/rspb.2005.3250

Brain size and resource specialization predict long-term population
trends in British birds

Susanne Shultz A1, Richard B. Bradbury A2, Karl L. Evans A3, Richard D. Gregory A2, Tim M. Blackburn A4 A1 School of Biological Sciences, University of Liverpool Population and Evolutionary Biology Research Group Liverpool L69 7ZB, UK
A2 RSPB Conservation Science The Lodge, Sandy SG19 2DL, UK
A3 Department of Animal and Plant Science, Sheffield University BIOME group Western Bank, Sheffield, S10 2TN
A4 School of Biosciences, University of Birmingham  Edgbaston,
Birmingham B15 2TT, UK


Large-scale population declines have been documented across many faunal assemblages. However, there is much variation in population trends for individual species, and few indications of which specific ecological
and behavioural characteristics are associated with such trends. We
used the British Common Birds Census (1968–1995) to identify specific traits associated with long-term abundance trends in UK farmland birds. Two factors, resource specialization and relative brain size, were significantly associated with population trend, such that species using atypical resources and with relatively small brains were most likely to have experienced overall declines. Further analyses of specific brain components indicated that the relative size of the telencephalon, the part of the brain associated with problem solving and complex behaviours, and the brain stem might be better predictors of population trend than overall brain size. These results suggest that flexibility in resource use and behaviour are the most important characteristics
for determining a species' ability to cope with large-scale habitat


  < 62 references snipped in the interests of brevity >

On Thursday, September 15, 2005, at 07:19  AM, John Leonard wrote:

Sounds like a piece of pop science to me. After all, birds have been around for millions of years and throughout all that time environments have been changing. If birds with smaller brians were disadvantaged per se then there wouldn't be any birds other than passerines in
existence by now. I think they need to go back and look for other

John L

On 9/14/05, knightl <> wrote:,,1569265,00.html

Birds with smaller brains less likely to survive

Alok Jha, science correspondent
Wednesday September 14, 2005
The Guardian

Being bird-brained is far worse than the jokes might have suggested.
Never mind that birds have never been one of the most intelligent
animals, research shows that the smaller a bird's brain, the more
likely the species is to die out in the wild.

British farmland bird populations have been declining for 50 years and
the accepted explanation is the intensification of agriculture. Based
on the fact that some species have survived better than others,
researchers looked for specific characteristics that influenced
survival rates.

Using data gathered by the British Trust for Ornithology between 1968
and 1995, they found that, as well as habitat loss through increased
agriculture, there were basic biological reasons influencing survival.
"There does seem to be a positive advantage to these birds in being
smart," said Tim Blackburn, an ecologist at the University of
Birmingham. "The size of the brain influences the probability that
these farmland birds are declining."

The population of great tits, for example, increased on farmland by
around 75%, and the number of magpies went up by 80%. However, the grey
partridge population fell by 75% and the lapwing by 40%. The relative
sizes of the brains in the former are bigger than those in the latter.

The brain has a variety of functions, but there are parts that
scientists think are the sites of higher-level function. In mammals,
the higher functions are concentrated in the cortex and the frontal
lobe. In birds, the equivalent is an area of the brain called the

"When you release a bird in an environment it is not naturally
distributed in, you'd expect that anything that could be more
behaviourally flexible might be able to take advantage of their
environment," said Dr Blackburn. "We think a similar thing may be going
on here: these brighter species have more opportunity to be flexible
and adapt to changing situations."

The results are published today in the Proceedings of the Royal Society
B: Biological Sciences. "I just really didn't think that we would find
these kinds of relationships," said Dr Blackburn. "It's not only that
it was a brain size effect, it's when you break the brain down into
these bits. The fact that it was the telencephalon that clearly came
out in our models, I was amazed."

Birding-Aus is now on the Web at
To unsubscribe from this mailing list, send the message 'unsubscribe
birding-aus' (no quotes, no Subject line)

John Leonard

Birding-Aus is now on the Web at
To unsubscribe from this mailing list, send the message 'unsubscribe
birding-aus' (no quotes, no Subject line)

<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the birding-aus mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU