 |
 |
Thanks very much, Nancy. This and the info at the Cornell link are quite fascinating, especially the observation that the pattern of white matches the timing of feather development. Most of the leucism or partial albinism we notice from time to time in other birds doesn't seem to reflect that kind of pattern, so more likely some genetic abnormality, it would seem. Thanks again, Jane Shoreham On 8/4/2010 8:46 PM, Walter Ellison wrote: > Hi Bob and others, > > As I looked at your photos of the black and white crow, I recalled a > similar bird that was brought in to the rehab center many years ago when > I worked at VINS. Dave Sibley illustrates one in his field guide as > well, saying they are "rare but regular". I call them "oreo" crows, for > the black-white-black pattern in the wings. Your photos also reveal a > hint of a fleshy gape, bluish eyes, and brown cast to the head and back > feathers that indicate that this is a young, recently fledged bird, as > was the one brought to VINS. It would seem that there is some > developmental anomaly that leads to this pattern, as the lack of pigment > occurs across all of the wing feathers (primaries, secondaries, coverts) > that would have been growing in at the same time. It's interesting that > the white banding doesn't show up in the tail feathers, and that adult > crows don't seem prone to the same variation (adults replace their > feathers sequentially, so wouldn't show an even white band). > > Crow researcher Kevin McGowan of Cornell University has an interesting > web page about white in crow plumage at > http://www.birds.cornell.edu/crows/whitecrows.htm > > Happy birding, > > Nancy Martin > Chestertown, MD >> -----Original Message----- >> From: Vermont Birds [mailto:[log in to unmask]] On Behalf Of Bob Dill >> Sent: Monday, August 02, 2010 10:03 PM >> To: [log in to unmask] >> Subject: Re: [VTBIRD] White Feathered Black Crow almost in Vermont. >> >> Late this afternoon I spotted a white feathered crow in a field just >> across the river in Lancaster NH (44.538466, -71.568332). I thought I >> would sneak up on the by rolling up on the side of the road....well they >> were crows and the were not fooled. They headed for the trees before I >> could get my camera up. >> How common are these? Does this occur in other black birds? >> >> Thanks, >> >> Bob >> >> The following is a link to a few pictures. >> http://picasaweb.google.com/bobdill112/Wwc?feat=directlink >> >> >> >> >