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Migrating Birds Take Hundreds of Powernaps.
Ant writes "MSNBC reports that to help make up for sleep lost during marathon night flights, migratory birds take hundreds of powernaps during the day, each lasting only a few seconds, a new study suggests.
Every autumn, Swainson's thrushes fly up to 3,000 miles from their breeding grounds in northern Canada and Alaska to winter in Central and South America. Come spring, the birds make the long trek back. The birds fly mostly at night and often for long hours at a time, leaving little time for sleep."
Humans do the same thing. The term is "microsleep", lasting from 2 to 30 seconds or so, often with eyes open. A quick search returns hundreds of PDFs on the phenomenon.
As usual, there is a WikiPedia entry (not very useful) and this site too: http://www.sleepdex.org/microsleep.htm
Hmmm... people do it. Birds do it. I'll be shocked when the research is published that fish do it too.
Space and Computers.
But the barn swallow typically migrates within within 100 feet of the ground .
Even more impressive is the behavior of the Wandering Albatross which can fly for days at a time within a wingspan of ocean waves (albeit their wingspan is about 10 feet). They can do this even during a full gale.
So how do they avoid crashing?
They soar. Wings generate lift just because they're there and under the right conditions a bird might well increase its altitude while napping.
As a wave moves through the air, or air moves over a hill, it compresses and rises. Thus a sleeping bird may find itself safely carried over variations in surface hight without having to do a thing. It's called "slope soaring."
KFG
Urban legend -- albatrosses sleep on the surface, not in flight.
_ and_flight
See http://en.wikipedia.org/wiki/Albatross#Morphology