How flocking waterfowl avoid collisions

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 =============================== To unsubscribe from this mailing list, send the message: unsubscribe (in the body of the message, with no Subject line) to: birding-aus-request@vicnet.net.au http://birding-aus.org ===============================