[Tweeters] What goose is this?
ixoreus at scattercreek.com
Wed Apr 18 08:44:09 PDT 2018
I too think this could be a White-fronted Goose, based on structure and bill color. But it’s a leucistic bird, rather than an albino.
Here’s part of a piece I wrote for BirdNote recently on the topic:
“The abnormal white feathers on these birds are the result of a genetic condition called leucism, which prevents any kind of pigment from reaching some—or sometimes all—of a bird’s feathers. The degree of leucism, including the brightness of the white and the extent of pigment loss, will vary with the bird’s genetic makeup. But the skin and eyes retain their normal pigment and color.
Leucistic birds are distinctly different from albino birds. Albinos are entirely white with pink eyes and skin. Albinism has a distinctly different origin: the absence or defect in an enzyme called tyrosinase, which is essential to the synthesis of melanin — the pigment that gives skin, hair, and eyes their color.
Leucistic individuals are much more prevalent among birds than albinos, and are most often seen in species we see large numbers of. Leucistic birds with symmetrical patches like white wings are sometimes referred to as pied or piebald. Some leucistic birds show, rather than white patches, a paler overall plumage that looks faint or washed out, as if partially bleached—for example a blackbird with areas of pale brown.
And when you see birds that have been selectively bred in captivity to develop all white plumage, it is leucism that lies behind the process.”
Good birding, Bob Sundstrom
Sent from my iPhone
> On Apr 17, 2018, at 7:57 PM, Martha Jordan <mj.cygnus at gmail.com> wrote:
> I got a note on our NWSCA Facebook page with two photos of a goose flying over a big body of water with a seagull of some type. The post person saw this on a birding post and asked me what I thought. All I know at this point that the location is Manchester (no other info provided).
> I think this is an albino white-fronted goose. The white area around the bill, the pattern of pale color, the shape of the bird, the whitish belly. And it looks like a 2012 posting of an albino white front in Germany.
> You can view this at: https://www.facebook.com/nwswans/posts/1711353722255034
> If you have trouble with the link let me know. I am curious about your opinions.
> Martha Jordan
> Executive Director
> Northwest Swan Conservation Association
> 206-713-3684 cell
> martha at nwswans.org
> 914 164th St SE, PMB 272
> Mill Creek, WA 98012
> Tweeters mailing list
> Tweeters at u.washington.edu
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