Why Is My Robin Half White? | BirdNote

A bird with abnormal white feathers, like this American Robin, may have a genetic condition called leucism. Leucism prevents pigments from reaching some — or sometimes all — of a bird’s feathers. Albino birds are distinctly different and are entirely white with pink skin and eyes. Albinos have trouble making melanin, the pigment in skin, feathers, and eyes.

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Why Is My Robin Half White?

Written by Bob Sundstrom

This is BirdNote.

Sometimes a real puzzler of a bird turns up. It might look like a regular robin, but with frosty white splotches on its head or back.

[American Robin https://macaulaylibrary.org/asset/83125241]

Or within a flock of blackbirds, a single bird jumps out because it has white instead of black wings.

[Red-winged Blackbird https://macaulaylibrary.org/asset/191788]

What’s going on? The abnormal feathers on these birds are the result of a genetic condition called leucism (pronounced LUKE-izm), which prevents pigments from reaching some—or sometimes all—of a bird's feathers. The degree of leucism varies with a bird's genetic makeup. But the skin and eyes remain their normal pigment and color.

Albino birds are distinctly different. Albinos are entirely white with pink eyes and skin. Albinism has a different origin, too: problems with an enzyme called tyrosinase. (pron: ty-RAHS-in-ayse) Problems with tyrosinase lead to problems making melanin, the pigment that gives skin, feathers, and eyes their color.

You are much more likely to see a leucistic bird than an albinistic one. Keep an eye out for birds that have white patches or washed-out plumage. It could be a bird of any species. Find photos of a few on our website: BirdNote Dot Org.

I’m Michael Stein.

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Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Recorded by Robert Bethel and Bob McGuire.
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© 2018 Tune In to Nature.org May 2018/2019 Narrator: Michael Stein

ID# leucism-01-2018-05-09 leucism-01

https://www.thespruce.com/bird-leucism-387342

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