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Re: brighter goldfinch-retraction



OOPS! Kent is correct. Feather wear does have an effect, but the bright yellow and black are mostly the result of honest-to-goodness molting.

Snow Buntings, on the other hand. . . . See Sibley's new book called Birding Basics.

Mea culpa.

Norm

At 03:19 PM 01/26/2003 -0500, you wrote:
Norman Budnitz wrote:
Goldfinches don't actually MOLT into brighter colors from now into
spring.  Those nice yellows are actually due to feather WEAR.  Lots of
surprises out there in nature!

You know, my first thought yesterday was to post exactly this same answer myself, but I decided to do some research first. Although many birds acquire their bright breeding colors through the wearing off of the dull feather tips that provide winter colors, apparently American Goldfinches do indeed have a full pre-alternate molt of the contour feathers, although not of flight feathers. I have a copy of Dwight's classic book on passerine molts that confirms this. A Google search on "goldfinch molt" turned up http://biology.queensu.ca/~amymac/research.htm which reports "The American Goldfinch (Carduelis tristis) is unique among Cardueline finches for its spring molt in which birds achieve brighter breeding plumage."

--
Kent Fiala
near Chapel Hill, NC




*********************************************************** Norman Budnitz, nbudnitz@duke.edu 919-684-3592 (day), 919-383-0553 (eve), 919-660-7293 (fax)

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