Have You Seen a Bird with White Feathers in Unusual Places?
Written by Andy McCormick
Andy McCormick, Volunteer and Former Board President of Eastside Audubon
If you have, you may be looking at a bird with leucism (pronounced luke-ism). The appearance of misplaced white feathers is the result of a genetic mutation which causes the condition known as leucism. As feathers grow, they are normally colored by pigment as they develop. The mutation prevents the pigment from reaching some, or in some cases, almost all of a bird’s feathers, resulting in a splotchy look, or in extreme cases, an all-white appearance. Leucism can occur in many different species of birds and mammals.
Examples of leucism abound in the bird world. Some examples include leucistic chickadees, hummingbirds, grackles, and crows. This year a leucistic Red-tailed Hawk was seen in Skagit County and recently an Eastside Audubon member sent a photo of an almost all-white Dark-Eyed Junco to the office.
Leucism is often confused with albinism, but they are different conditions. The absence of pigment caused by leucism effects only the feathers. The skin and eyes retain their normal color. However, an albino bird will often have pink eyes and skin.
A Bird Note program on leucism is located on the National Audubon Society website where you can listen to the program and read a short article. https://www.audubon.org/news/why-bird-half-white
USE STRUCTURE TO HELP IDENTIFY BIRDS
We often focus on color first when trying to identify birds. When that usual picture of a bird is disrupted by color in the “wrong places,” such as by leucism, we can become confused. Leucism can help us to remember to consider the structure of a bird when trying to identify an unusual looking bird. Try looking at the shape and proportion of a bird without focusing on the color. A way to practice this is to take a few minutes to thumb through your field guide and pay attention to the size and shape of birds.
The Sibley Guide paintings of birds stand out well against the white pages making it a little easier to imagine the bird with no color. Silhouettes of birds have been featured on the front and end plates of Peterson field guides for over 50 years. They are well worth reviewing every so often.
When you are in the field and a bird is back-lit by the sun, take advantage of the opportunity to try to identify the bird by its size and shape alone. Then watch as it flies to see how you did. Even getting a bird into it family moves you much closer to an identification. Knowing a bird is a sparrow narrows your choices significantly. The shape, size, and structure of the bird can often help you assign it to a family.
Photo credit by Budgora.