Perfectly Imperfect Plumage

Discover why birds develop surprising and irregular feather colors.

- Kenn And Kimberly Kaufman

SEEING BIRDS PARADE such colorful feathers is one of the greatest joys in watching winged visitors. The hues and patterns of their plumage are both decorative and practical, making them gaudy enough to attract mates or subtle enough to blend into their surroundings. Plumage is also a reliable way for bird-watchers to recognize different species.

Sometimes, though, a bird has a very unusual feather pattern—one that is not quite how it’s supposed to look or doesn’t match up with the pictures in the book. Such striking and surprising colors have a number of causes. If you know what makes these odd variations possible, it’s exciting, not confusing, when you spot one.

FLASHES OF WHITE

A flock of robins gather on the lawn and among them is a bird that looks similar, but with big patches of white. A flock of house sparrows flies past, and there’s an all-white bird with them. Are they some rare visitors?

No, they’re just individuals of the same kind that lack normal pigments in their feathers.

Most of the black, gray, brown and reddish-brown tones in feathers are created by pigments called melanins. If these pigments are missing, feathers may grow in pure white. Birds might have just a few white feathers, large random spots of them—or they might look completely white. All of these individuals are known as leucistic. Their appearance may throw you off at first, but with careful study, you can identify most by their shape and behavior, and if they’re flocking with others of their own kind.