On Tue, 17 Jun 2008 14:29:15 -0500, TRoss wrote:

Without going into the airspeed velocity of an unladen swallow....

You are trying to photograph a 6" bird that can hit speeds of 45mph.
Your reaction time and the autofocus speed just can't keep up.

I would set the camera on a tripod, focus on the closest nest colony,
and use a small aperture to increase the DOF. A shutter speed of
1/1250 should be fast enough to stop the motion, and it would give you
more depth. I would also set the drive shoot in bursts.

If the shooting distance is close enough and your flash supports
high-speed sync, it might help to freeze the action or provide a
little fill.

Thanks. I was using flash, my Metz 45CT-4 on manual full power, but
the flash was not keeping up by far, and was barely close enough to
make a difference. And it was not possible to get closer... short of
building a scaffold.

I will try the slower shutter speed... will help the DoF and may still
stop the motion enough.

Archibald