Thursday, March 23, 2006

University College (of Life) Dunlin

A fascinating article in the latest issue of Canadian Geographic (subscription required) by Dick Dekker focuses on the flight choreography of dunlins, a type of shorebird, in Boundary Bay, British Columbia. Dekker explains his theory that the birds choreograph their flights with the tides in order to escape the clutches of killer falcons. Observing that the birds spend a large amount of time flying over the ocean rather than landing on shore, he says he came to suspect that the over-ocean flights of the dunlins were an anti-predator strategy because the birds are safer from surprise attacks by falcons when they are over water. Interesingly, while in flight, the bird flock increases in density as all its members strive to reach the safest position, in the center. Dekker reports the finding of scientists that the majority of kills by falcons are of juveniles, suggesting that the dominant adults tend to fight their way into the safer center of the flock.

The bastards.

The same issue also features an article by C. J. Conway on the recent increase in number of derailments of rail cars carrying toxic materials in Canada, an increase that he says has coincided with major consolidation and change in railroading, with management cutting the number of workers, using less fuel, and transporting higher-revenue traffic.

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