In response to Katie Sauter's posting:

1) Corvids are about the most intelligent and apparently the most playful
(= exploring new feelings or things) of birds. Nothing they did would
surprise me very much. Crows and ravens, being superb aerialists, have the
best of worlds.

2) I agree entirely with Chris Hill (I think he was the source; I had to
clean out my mailbox when it wouldn't let me put anything more in the
trash!) who, if I remember rightly, thought the gray jay was playing, while
the rock dove made a dumb mistake. Sorry, all you pigeon fanciers, but
pigeons are in a whole different class from corvids. The Ross' gull
probably represents a different phenomenon. Many birds use currents; they
fly upstream (upcurrent in salt water), then ride downstream while
foraging, then back upstream again to repeat it. The gull wasn't foraging,
but it *was* preening extensively while I watched it ride downstream, then
it flew back to the dam to feed.

3) Birds descend from high altitude very commonly by turning sideways or
virtually upside-down to lose all their lift; remember, as long as they are
right-side up and have their wings open, they generate lift. The other way
to get down would be the peregrine method, by merely closing the wings and
dropping like a rock, and perhaps this method just doesn't work for most
birds. For birds with larger wings, it might be too much of a shock to open
them at the end of an accelerated fall, whereas, by turning upside-down,
they can just reverse the movement and stop their fall instantly. I would
love to have a movie of this behavior in several types of birds to be able
to analyze it in slow motion and see exactly what happens.

I've seen this "falling-leaf" behavior in many kinds of ducks, geese,
herons, storks, ibises, gulls, and other birds that were high and wanted to
get low--fast! It *is* an impressive and startling behavior, but I've
never seen a crash. Hawks all seem to lose altitude merely by closing their
wings, a thing they should be able to do to stoop on their prey. It would
be interesting to see how far this dichotomy extends.

Dennis Paulson phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416