This Morning Outside

by Diane Porter

March 11, 2011
Birdwatching Dot Com
Fairfield, Iowa

The wind caught and ruffled the breast feathers of the downy woodpecker. And let out a secret — the bases of those snowy feathers are drab gray!

It takes metabolic effort to structure feathers to appear white. So only the outer end of each feather is white.

Photo copyright 2011 Michael and Diane Porter

White feathers are white not because of pigment but because of the microscopic architecture of the feathers, which appear crystalline when magnified. The white comes at least partly from many tiny pockets of air in the fine barbs of the feather, which scatter light of all frequencies.

Mother Nature conserves the woodpecker's energy by making only the tips of the feathers white, only the parts that show.

—Diane Porter

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