Air Date: Week of May 11, 2012

(Photo: Andrew Reding)

The Swainson’s Thrush is something of a night owl – it stays up all night and travels long distances. And when it needs some zzzzzzzz’s, the bird takes daytime mini-naps, sleeping with one eye open. Mary McCann reports.

Transcript

[BIRD NOTE® THEME]

GELLERMAN: Sometimes even birds need a little catnap. BirdNote®’s Mary McCann has this story about 40 winks, with nary a blink.

[SONG OF THE SWAINSON’S THRUSH]

MCCANN: If you’re lucky, in late spring in the forests of the North and West you’ll hear the melodious, spiraling song of the Swainson’s Thrush. It will linger with you like your body’s memory of a gentle swell after a day on the open water.

[SONG OF THE SWAINSON’S THRUSH]

MCCANN: March finds these secretive, bright-eyed singers departing their wintering grounds in Mexico and South America. They travel at night and can cover more than 200 miles in some eight hours of flying. To replenish themselves from the rigors of their journey, they must stop and feed during the day. When do they sleep?

[“QUIP” CALL OF THE SWAINSON’S THRUSH]

MCCANN: Research by Dr. Thomas Fuchs of Pennsylvania State University suggests that while migrating, Swainson’s Thrushes take numerous daytime “micro naps,” lasting only a few seconds. The birds are also apparently able to rest half their brain by sleeping with one eye closed. The other eye remains open, with half the brain alert for threats from predators.

When they arrive on their breeding grounds in mid-May, you’d think they’d be ready for a long rest. But the demanding tasks of establishing a territory and finding a mate await them immediately. And that’s why the male thrush sings that haunting song.

[SONG OF THE SWAINSON’S THRUSH]

MCCANN: I’m Mary McCann.

GELLERMAN: To get an eyeful of a Swainson’s Thrush, wing it over to our webpage LOE dot org.

 

Links

Audio of the Swainson’s Thrush provided by The Macaulay Library at the Cornell Lab of Ornithology, Ithaca, New York. Song and “quip” call recorded by G.A. Keller.

Swainson’s Thrush, “Micro Napper” was written by Todd Peterson. Check out BirdNote’s new website.