This audio story is brought to you by BirdNote, a partner of the National Audubon Society. BirdNote episodes air daily on public radio stations nationwide.
Transcript:
This is BirdNote.
The next time you’re watching a baseball game, pay attention to those dark patches under the players’ eyes. It’s called eye black. Players use it to reduce glare from the sun or stadium lights.
Many birds have evolved areas of dark feathers across their eyes. Shrikes have a wrap-around sunglasses look, and kingbirds have something similar. Both hunt from exposed perches in the bright sunlight.
Some scientists think the markings help disguise where the bird is looking, helping to catch prey off-guard.
Scientists in Israel tested this theory with Masked Shrikes.
Some shrikes were temporarily “unmasked”: the researchers whitened the black feathers. These birds altered their normal hunting angle, facing away from the sun’s glare instead of into it. Success in catching prey dropped.
The researchers think the shrikes that hunt facing into the glare are less easily detected because they don’t cast a shadow in the direction of their prey.
Some birds that live in the shade, like this Red-breasted Nuthatch, also have bold black markings across the eye. And still others have black masks only seasonally, and some only in one sex.
Just how these markings work is still a question for future research.
But for the Masked Shrike, a black mask makes it a lot easier to get its next meal.
For BirdNote, I’m Michael Stein.
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Credits:
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Recorded by Arnoud B. van den Berg and Geoffrey A. Keller.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Managing Producer: Jason Saul
Associate Producer: Ellen Blackstone
Narrator: Michael Stein
Writer: Bob Sundstrom
© 2018 Tune In to Nature.org, July 2018