[obol] Re: article on identifying long billed vs short billed dowitchers
- From: David Irons <llsdirons@xxxxxxx>
- To: "stephaniehazen17@xxxxxxxxx" <stephaniehazen17@xxxxxxxxx>, OBOL Oregon Birders Online <obol@xxxxxxxxxxxxx>
- Date: Wed, 28 Aug 2013 07:07:36 +0000
Greetings All,
The article at the link provided by Stephanie Hazen is not "good" and in fact
it will probably cause you to become more confused about dowitcher ID than you
may be already. In my opinion, none of the so-called "new" field marks that Lee
and Birch present are reliable or even particularly helpful. The worst of these
is "loral angle." Even the slightest change in photo angle or the angle at
which a dowitcher is holding its head will significantly change the perceived
loral angle (as described by the authors). Last September, I took a series of
photos of a juv. Long-billed Dowitcher at Crescent City, CA. As the bird moved
along feeding the loral angle changed dramatically from photo to photo.
Shawneen Finnegan is absolutely SPOT ON in her response and comments posted
earlier. If you don't first age a fall shorebird, you are almost certain to
make a mess of trying to ID it to species. This is particularly true of the
smaller Calidrid sandpipers (Least, Western, Semipalmated, and Baird's
Sandpipers, along with Dunlin). It is also true of dowitchers.
As Shawneen correctly points out, there are NO Long-billed Dowitchers in any of
photos that Stephanie posted. They are all Short-billeds and they are all
juveniles. Trying to use underwing pattern, tail pattern, or, worse yet, loral
angle to ID these birds is a mistake. Look at the tertials. If a dowitcher is a
juvenile and its tertials are broadly edged with rusty-orange and have
laterally "tiger stripes" or barring, the bird is a Short-billed. If it's a
juvenile and the tertials are unbarred and have narrow pale or rusty edges,
then the bird is a Long-billed Dowitcher.
The links below will take you to the BirdFellow Social Field Guide ID galleries
for the two dowitcher species. Check out the images notated below. They
illustrate what Shawneen describes in her excellent post.
http://www.birdfellow.com/birds/short-billed-dowitcher-limnodromus-griseus#/idPhotos
Images 11-27 are all juvenile/hatch-year Short-billed Dowitchers in either
juvenile plumage or transitioning from juvenile to formative (first winter)
plumage. Note that all still have barred tertials.
http://www.birdfellow.com/birds/long-billed-dowitcher-limnodromus-scolopaceus#/idPhotos
Images 8-12 are all juvenile Long-billed Dowitchers.
I would use caution when it comes to blindly accepting articles that promote
"new" or "cutting edge" field marks. Field test them on birds of known identity
(dowitchers are easily separated by voice). If you see a large flock of
dowitchers of one species, look at the individual variation and then see if can
find birds that defy the criteria put forth in the Lee and Birch article.
Dave IronsPortland, OR
> From: stephaniehazen17@xxxxxxxxx
> Subject: [obol] article on identifying long billed vs short billed dowitchers
> Date: Tue, 27 Aug 2013 20:35:35 -0700
> To: obol@xxxxxxxxxxxxx
>
> http://www.surfbirds.com/ID%20Articles/dowitchers1005/dowitchers.html
>
> Good article, long read, on identifying long billed vs short billed
> dowitchers. I still think we have long billed. Wide black bands in tail
> feathers for one.
>
> Stephanie
>
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