Monday, September 27, 2010

Warbler Guy, do the white tail spots in the Hooded Warbler (and other warbler species) provide it any benefit?

Catrina (in Portland, OR), the answer is “yes,” if you agree with studies conducted by Dr. Ron Mumme. In the field, he tested his hypothesis that the Hooded Warbler’s (above photo courtesy of Dr. Mumme) contrasting white tail spots and tail-flicking behavior increase foraging performance by startling potential insect prey that the warblers then pursue and capture in flight.

Results of his experiment indicated that Hooded Warbler individuals with darkened tails had significantly lower prey attack rates and delivered significantly less food to nestlings than did birds with normal, unchanged tail feathers. He and other theorists continue to test their theory about the importance of contrasting tail pattern in helping birds capture prey, and, in doing so, note that all 12 species in the Myioborus redstarts (also known as whitestarts) display similar behavior while using their white outer tail feathers to also conduct foraging displays designed to startle and flush potential insect prey.

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