Tuesday, June 11, 2013

Wilson's Phalarope

Wilson's Phalarope - Phalaropus tricolor

This phalarope is named after Alexander Wilson, a prominent North American ornithologist whose name is also attached to a variety of other birds including a warbler and a snipe. 

The female chooses the male and then in a reversal of the common role, leaves the nest building, incubation, and chick raising to the male. The female is larger than the male and defends the nesting territory. The female may have more than one mate (polyandry).

Phalaropes feed by picking minute food particles from the water at or near the surface. 

The swimming pattern of a phalarope creates waves (small whirlpool) that raises insect larvae and other food particles to the surface, which allows easy access to their forceps-like bill.  

Small food items are transported along the bill using surface tension. The bird captures a drop of water with a prey item in the bill tip and then opens the bill so the drop moves toward the mouth, then closes the bill, squeezes and shakes the remaining water from the bill, and ingests the prey. 
Hundred's of thousands of Wilson's phalaropes congregate in the salt flats in Utah to fatten up and molt before making their southern migration journey to South America. 

The Atlas of Breeding Birds of Alberta. Federation of Alberta Naturalists. 2007.

Baicich PJ, Harrison CJO. Nests, Eggs, and Nestlings of North American Birds. Princeton UP. 2005.

Beadle D, Rising J. Sparrows of the United States and Canada. Princeton UP. 2003.

Fisher C, Acorn J. Birds of Alberta. Lone Pine Publishing. Edmonton. 1998.

Sibley David A. The Sibley Guide to Bird Life and Behavior. Alfred A Knopf, Inc. New York. 2001.

Tudge Colin. The Bird. Crown Publishers. New York. 2008.

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