Birds of a Feather
By Patricia Rogler
Most birds have very colorful feathers: the parrots’ are bright green, bluebirds’ are shiny blue, and goldfinches’ are a lovely yellow. So where do these colors come from? Usually, they are a product of pigmentation and structural design.
Three Types of Pigments
There are three different pigments that affect the colors of feathers. They are called melanins, carotenoids and porphyrines. Melanins produce a variety of colors, including black and shades of reddish browns and yellows, which are expressed based on concentration and location (on the feather).
Melanins not only give feathers color, but also strengthen the wings. Carotenoids are found in plants, and birds that eat these plants can produces colors such as pinks, browns, reds and greens.
Structural Colors
Some colors in birds’ feathers are due to the structure of the feather itself and the way light bounces off of it. At different angles, the feathers appear to be different colors. The hummingbird, for example, appears to have iridescent feathers because the structure of its feathers breaks up light into a range of colors that shimmer and change. Sometimes the structural color interacts with the pigments and creates a different color of feather. Parrots, for example, have a blue structural color and a yellow pigment color, resulting in green-colored feathers. Some feather structures reflect light in the ultraviolet range. Because many birds can see a greater range of colors than humans can, a bird’s own feathers may appear to be a different color to species members than to humans.
With over 9,000 species of birds in the world, there are almost as many varieties of feather colors due to the various structures and pigments and how they combine.
Classroom Discussion
What color combinations can you create by mixing a structural color with a pigment?
Name your favorite bird and what different combination of pigment and/or structure could create the color of its feathers