I have just read an article in the August 17, 2013 edition of The Economist
which describes the results of a research project carried out by Hynek Burda
of the Czech University of Life Sciences in Prague showing that landing
flocks of waterfowl avoid collisions with each other by always landing on an
axis along (or very close to) the two magnetic poles. Whilst I have no
problem with the concept that birds use the earth's magnetic field to
navigate, I have to say that my engineer's brain grew somewhat sceptical
about these conclusions. It would seem to me that there would be many
factors affecting the landing direction of waterfowl including things such
as wind strength and direction, avoidance of obstacles, avoidance of
locations which could hide predators, geometry of the body of water, etc.
Also the fact that birds see real time more slowly than humans would seem to
indicate that they could quite easily avoid collisions by minor course
changes as they approach their landing. A further thing which struck me was
that the sample size seemed pretty small for a year's study.
However, this is all just the somewhat sceptical qualitative opinions of an
engineer and I would be interested to hear the views of the scientists on
birding-aus. The full abstract of the article is at the link below.
http://www.frontiersinzoology.com/content/10/1/38
Cheers
Roger McGovern
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