Does that bird have xanthochroism?

Written by Jack Sanders
Thursday, 09 June 2011 12:46

Always expect the unexpected, especially when watching birds. Roland Walters can attest to that, thanks to a woodpecker he has had around his Ridgefield home.

“I have a bird variation to report, a Downy with yellow stripes over her eyes where you normally find white,” he writes. “I’m assuming she’s a female because she has no red crown/crest. Did you ever hear of this or do you know what’s going on? This is most likely a juvenile although oddly, I haven’t seen the fledglings, except for a lone little one way back in the bitter cold of February or March, if I didn’t write you about her at that time. I find one Web site that mentions ‘Downy’ and ‘yellow,’ but it hints at staining and what I have is surely not staining.”

Xanthochroism is a pigmentation malfunction that may express itself by producing an excess of yellow in feathers or the yellow replaces another color, especially red. While the condition is very rare, it is apparently more often seen in woodpeckers than in many other species.

Scientists believe the variation is genetic, but it could be connected with diet.

Xanthochroism is not limited to birds.  Fish, amphibians and other kinds of creatures can have the defect.  A normally green frog could wind up yellow, which would be a rather shocking sight.

Three other kinds of pigment defects or disorders can affect bird coloration:

Albinism is the lack of melanin, which results in white feathers. It also produces reddish eyes, legs, feet, and beak — because the blood vessels, normally masked by the melanin, are showing.

Leucism is an abnormal melanin placement. It could result in a bird with all-whitish feathers or in one with only some normally colored feathers  that are white. (Leucistic birds have dark eyes instead of red or pink eyes, often used as a way to tell which defect is present.)

Melanism is excessive melanin, resulting in darker than usual birds (we more often see this phenomenon displayed in “black squirrels,” which are fairly common around here).

Safflower seeds

Pat Warren of Darien, who owns Wild Birds Unlimited stores in that town and in Bedford Hills, has some observations on summertime bird feeding.

“You can feed the birds seed with no shell and keep the mess away during the summer months when we spend more time outside,” she writes.

“Better yet, try safflower and keep the crows and grackles away for sure!  Safflower really works and I’m amazed more people don’t know of this miracle seed that cuts down on gangs of birds crowding the feeder.

“Do the other birds like safflower? You bet — especially the cardinals.  Because safflower is a different taste to the birds, when a person initially switches to it from a black oil sunflower mix, the birds will scatter it like crazy — looking for the black oil or other familiar seeds. However, once they realize the diner is only serving safflower for the summer, they settle down and enjoy what’s there.

“Also, the safflower is not an acidic seed like the black oil, so no harm when it lands on the ground anyway.

“Safflower does need to be used almost exclusively in feeders — i.e. no mixing with other seed or some in one feeder and not all, otherwise the gangs of crows and grackles will come around still.

Coming up

Field trips to various locations, all day: Thursday, June 16 (Bashakill Marsh and the Shawangunk Grasslands), and Tuesday, June 28 (Clough Preserve), Bedford Audubon, register with Jeanne Pollock at This e-mail address is being protected from spambots. You need JavaScript enabled to view it or 914-519-7801, bedfordaudubon.org .

Summer Bird Count, volunteers needed, all ages, Saturday and Sunday, June 11 and 12, starts at 5:30 a.m., then all day, Audubon Greenwich, 613 Riversville Road, 203-869-5272  x230, greenwich.audubon.org

eBird Workshop, about online bird checklist program launched by the Cornell Lab of Ornithology and National Audubon Society, Saturday, June 11, 1 to 3 p.m., Bedford Audubon, at Westmoreland Sanctuary, 260 Chestnut Ridge Road, Bedford Corners, N.Y.  to register, call at 914-666-8448 or email Adam Zorn at This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Copyright 2011 by Jack Sanders. Send sightings or comments to: jackfsanders [at sign] yahoo.com, or to Bird Notes, Box 1019, Ridgefield, CT 06877; or call 203-438-1183, extension BIRD (2473), and leave a message with your report, spelling your first and last names and telling us your town. If you need help identifying a bird, try your local nature center. If you find an injured bird, call wildlife rehabilitator Darlene Wimbrow of Redding, 203-438-0618, Wildlife in Crisis of Weston, 203-544-9913, or Wild Wings of Greenwich, 203-637-9822. The columnist’s website is www. sandersbooks. com.