The rotating is typical of half-brain sleeping in birds. They can maintain
surveillance with an open eye and the half-brain that is awake, but need to
rotate more to cover the angles. In roosting flocks, those at the edge tend
to do more half-brain sleeping than those in center of the roosting flock.

Gary Shugart
Collections Manager
Slater Museum of Natural History
University of Puget Sound
Tacoma, WA 98416
253 879-3356 (museum)
gshugart at ups.edu
http://www.ups.edu/slatermuseum.xml
http://digitalcollections.ups.edu
***************************
From: Lee Rentz <lee AT leerentz.com>
Date: Sat, 28 Oct 2006 22:30:14 -0700

I am curious: after years of seeing all sorts of shorebirds resting
on one foot, I realized that I really don't know why they often rest
that way. The one explanation I ran across suggested the behavior is
for heat regulation?important for birds that spend a lot of time
wading in cold water.

While recently watching the Marbled Godwits in Tokeland for a long
time, I noticed that when a godwit is resting on one foot, head and
bill tucked into its back feathers?but with eyes open?it can rotate
its body around in an arc and check on its surroundings. I had
always assumed they were essentially asleep when in this position,
but clearly they can be very aware. In fact, I wonder if the
rotating ability might make resting safer on one foot than on two feet.

Any ideas or observations?

Lee Rentz
lee AT leerentz.com
Shelton, WA_______________________________________________
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