Dan Stephens:
>migrating-we just could not see them. Do hawks migrate through
>inclement weather? Don?

Accipiters tend to roost if it's really nasty, but in my experience
a few continue to move. It may have to do more with the fact that
bad weather breaks up the normal pattern of airflow on a ridge,
i.e. thermals disappear and sharpies, at least, seem to have trouble
handling the kind of winds we see during thunderstorms, etc at the
Goshutes. Males will fold up like one of NASA's old flying bodies
(if you've ever seen pictures - wingless flying machines) and you
can see them bouncing up and down in rough, windy air. Couple that
with rain and clouds and the fact that sharpies like to hug the
ridgeline and you can see that perhaps flying in conditions of
high wind and low visibility would be selected against over time.

I've seen sharpies try to land on a lure in high wind, and when
flaring get blown out of the station as though they've been hit
by a tennis racket. Literally. Few even try to capture a lure
in high winds.

And buteos definitely prefer to fly when thermals are available.


- Don Baccus, Portland OR <donb at rational.com>