Hello Ohio Birders,

My 2c on the panic-at-eagles'-approach issue:  My birding goes back to
pre-DDT, at least to a time when it (DDT) had not yet affected peregrines
much.  Each fall, just about every shorebird staging area in the northeast
(Biddeford Pool, ME, Plum Island and Monomoy, MA, Cape May, Bombay Hook,
etc.) had a few migrant peregrines hanging around picking off shorebirds.
It was great fun to watch the peregines stooping into shorebird flocks at
100+ mph and to see the cloud of feathers and hear the delayed "pop" that
denoted a succssful kill.  I suspect that this process, along most of the
migration route year in and year out has brought aout an innate response to
take wing when any large bird appears overhead, especially among those
species that nest in the Arctic where there there are gyrfalcons and jaegers
to contend with.  Sure, most of the time the threat is empty (eagles,
harriers, etc.) but the quick, innate response is still there.  One could
argue that the shorebirds might be safer if they just sit tight but the
birds obviously don't know this.  If you take wing as part of a large flock,
your own chances of being killed are still fairly low, so one can see the
adaptive value of the behavior.

I've rarely seen killdeer take wing at the sight of a raptor, but killdeer
are more sedentary and solitary and their gene pool probably has not been
pressured much by raptors.

Some enterprising student could look into this by flying model aircraft, or
boomerangs, of various shapes and speeds over flocks of foraging shorebirds,
and quantifying the response.

Happy birding,

Dave Horn

______________________________________________________________________

Ohio-birds mailing list, a service of the Ohio Ornithological Society.
Our thanks to Miami University for hosting this mailing list.
Additional discussions can be found in our forums, at www.ohiobirds.org/forum/.

You can join or leave the list, or change your options, at:
http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS
Send questions or comments about the list to: [log in to unmask]