Whirlybird

Jun 10, 2008 06:20

Would have posted this sooner but a tornado went thru our backyard and knocked out all the power ( and removed the fences, neighbours roof, clothesline, and half the garden )

Been catching up on my New Scientist . The issue for May 24th hit a rich vein of what-the-fuckery, which I'll be happily regurgitating for you.

Here's the first ( suitably tagged - I'd happily volunteer for mod-status if that means I can prune out half the tags we don't need. I'm already adding ones we do use. )

They swim in circles to draw food-laden seawater up to the surface.

They use surface tension to suck water up their beak.

They look like "demented wind-up toys" when doing so.

Ladies and gentlemen, I give you the Phalarope.

Phalaropes are small shore-birds that feed on tiny crustaceans. The mystery was how they managed to do it, since the copepods quite wisely avoid swimming too close to the surface, and the Phalaropes could hardly waste time and energy diving after such minute prey items. They don't even dip their heads under the water.

Researchers eventually discovered that it was the spinning-around-on-the-surface that formed a vortex that drew the copepods up into feeding range, but that didn't answer the full question. Phalarope beaks are the wrong shape to suck with, and Margaret Rubega suspected it was the epileptic scissoring-action that drew water further up the beak. It turns out she was right - drops of seawater and the copepods within are squashed, stretched, and squashed again, each iteration drawing it a little higher up the beak.

Unfortunately, the team also confirmed that even small traces of any oil would destroy the ability of the beak to use surface tension this way, leaving the poor little whirlybirds to starve. :(

bird, feeding, predator

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