I’ve been looking through eBird checklists that include
Short-billed Dowitchers and a number of comments reminded me just
how challenging it can be to ID breeding plumage adult dowitchers
so I thought I’d throw out some things that have helped me.
Before I get started I want to point out that the Andrew Birch /
Cin-Ty Lee article which was published in Birding magazine has
been widely criticized, for good reason. When I first became aware
of it I was very excited. I read and reread it, studied the new
“field marks”, and when spring came I went out to pick through
dowitchers (more on this later). Long story short, I found the
article almost useless and was glad when others voiced their
concerns about the field marks it presented. So, buyer beware. I
won’t go into details but I will say the only thing in the article
that seems consistent (read useful) is the kink in the bill of
Short-billed about 1/3 of the way back from the tip. It’s a sharp
kink, not an even curve. Long-billeds also can have a droop but
it’s less restricted (or more curved than kinked if that makes any
sense?) and more towards the center of the bill. The kink is not
always present but so far I’ve only seen this on birds that could
be identified as Short-billeds using other field marks.
Rather than start from scratch I’m going to copy some of what
I’ve written in the past but I want to start by pointing out that
the most important step when trying to ID dowitchers (or any
shorebirds) is aging the birds. It’s surprising how many ebird
checklists include comments describing striped tertials on adults
and spots on breast sides of juveniles. Both are irrelevant. Right
now there are only adults – there are no juveniles in spring and
adults of both species have stripes on their tertials. When fall
migrants begin to appear you can find either age but they’re easy
to tell apart because the adults are worn and the juveniles are in
fresh plumage.
That said here are some thoughts on identifying adults in spring.
Primary extension can be helpful but it is variable and some SBDOs
do not show much, or any, extension beyond the tail. The right
hand bird in this photo is a good example:
I still struggle with breeding plumage dowitchers but there are
some things that seem to work.
-Spots on the side of the breast. The left hand bird in the above
photo has distinct spots on the side of the breast ahead of the
wing. These spots are on the feather shaft well away from the tip
of the feather and are diagnostic if present.
-SBDO often shows quite a bit of white on the belly, flanks and/or
vent, again like the left hand bird above. Here’s another example
that also shows obvious spots on the breast sides:
-Orange of underparts is paler and more orange on SBDO, not as
dark and rufous as LBDO.
-SBDO has less black spotting on the center of the throat, often
clean, unmarked orange that’s quite distinctive. Here’s another
photo that illustrate these last two points (right hand bird).
-Bill of SBDO often appears slightly drooped near the tip, but
I’ve seen a couple LBDOs that appear to have a slight droop as
well, albeit further from the tip of the bill, so I would suggest
using this with caution.
-Markings on edges of feathers and internal markings on
scaps/coverts of SBDO are often paler golden buff than the rufous
of LBDO.
Hopefully you’ll find some of this useful. I still try to verify
identification by flushing possible SBDOs hoping they call and
still leave some as ???
I recently found these pages that seem useful:
http://tgreybirds.com/Pages/LongbilledDowitcherp.html
http://tgreybirds.com/Pages/ShortbilledDowitcherp.html – this page
details a Short-billed field mark I hadn’t seen before. The pale
tips of the flank feather are washed orange, not bright white as
on Long-billed. So far this seems to be consistent but I don’t
know if it’s totally reliable.
Now I want to revisit the Birding article. I went out and tried
to apply the new field marks and became skeptical of their
validity so I posted some photos to the ID Frontiers listserv
requesting opinions. I’m going to put the photos below but
withhold my guesses on the IDs and what the experts had to say for
now. If you’re up for the challenge take a look and try to ID them
and see if you do better than I did. Which do you think are
Long-billed and which are Short-billed?
These photos were all taken on Island Park Reservoir in Idaho.
Photo #1: This was taken on May 27
Photo #2: This one was taken on May 20
Photos 3 & 4: Taken on May 14
Photos 5 & 6: Taken on May 14
-- Cliff and Lisa Weisse Island Park, Idaho cliffandlisa@...