Jerry Jourdan posted some nice photos from Pointe Mouillee on the
Michigan list
http://www.birdingonthe.net/mailinglists/MICH.html#1186936220 yesterday,
and invited discussion. Some are especially helpful for one tough ID
that comes up this time of year at our latitude: separating the adult
dowitchers. He offers a photo of a couple of long-bills at
http://www.pbase.com/jourdaj/image/83756432  that are worth studying to
this end.
        In order of reliability, the characters most indicative of LBD here are:
        (1) the fact that they are adults in breeding plumage in active molt.
Adult SBDs don't normally molt southbound, but LBDs usually arrive here
in heavy molt (including flight feathers, and missing ones are easy to
see when they're flying). Look at all the fresh gray basic feathers
already molted onto the back of the right-hand bird.
        (2)  both these birds show dense dark barring on the upper breast,
above the bend of the wing. Our SBDs never show more than light spotting
here.
        (3) less reliable, but still indicative clues include the predominance
of the width of black stripes over white ones on the uppertail, the
length of the bill (~twice the head length here), and deep rusty red
tones beneath that extend the length of the underparts.
These three clues, even taken together, are not enough to clinch the ID,
however.
        (4) other useful features include that by this time of year, juvenal
SBDs are starting to outnumber adults; juvenal LBDs probably won't
appear in Ohio till next month. And there are well-known and reliable
plumage details to tell juveniles apart in September when they're both
around.
        Recently some morphological ID hints have been suggested: a burlier,
"swallowed-a-grapefruit" body shape for LBDs, and differences in various
angles of facial/bill features. I don't see them here, but they will
continue to be tested. Don't forget that their voices are quite
different, and described in field guides: LBDs are more talkative, at
least in a group, SBDs are more likely to vocalize only when disturbed.
        Here's hoping everyone has a chance to study these beautiful birds this
fall. The SBDs we see are of the "prairie" race hendersoni, the most
colorful and most endangered of the three subspecies. Many field guides
are aimed at the coasts, rather than Ohio and other fly-over states, so
they make light of the hendersoni ID problems; the coasts host two more
numerous and different-looking SBD subspecies. LBDs are far more
numerous in N. America, but in Ohio overall SBDs are more often seen;
all but a tiny proportion are hendersoni.
Bill Whan
Columbus

______________________________________________________________________

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]