Re: Need help with a shorebird ID

["Cliff and Lisa Weisse" <october at ida dot net>]

Matt makes some interesting observations about these birds.
The white bars on the tail of the dowitcher in the second
photo do appear wider than the black.  However I feel this
is an unreliable mark, especially in photos.  Case in point,
take a look at the photos of the Long-tailed Jaeger at
www.octoberweb.com/birds/ltja.  In the second photo from the
top the same effect is visible on the undertail coverts,
white bars wider than the black.  In the field the bars were
of the same width.  We viewed the bird from as little as
thirty yards with a 60X scope so I'm sure of this mark.
Compare the second photo to the pattern in the flight shots
and you can see that the width of the bars appears different
even between photos.

Regarding the bill of left bird in photo 4, I again agree
that it looks shorter.  As Matt points out this is in part
due to the position of the bird's head, facing the camera,
but there is considerable difference in bill length between
males and females (females are longer billed).  If you look
closely at a flock of Long-billed Dowitchers, which is what
I usually get to see flocks of in Idaho, you can see an
obvious difference in bill length between individual birds.
Also if you take a look at the photo above, the third one
down, you have the same three birds in the same position
(only the other two have raised their heads) and the bill
looks considerably longer than it does in the fourth photo.

As for migration I checked the data in Paulson's Shorebirds
of the Pacific Northwest.  This data is for further north so
earlier is to be expected in Utah.  The early date for
Short-billed Dowitchers on the coast is March 20 and for the
interior region it's April 28.  I should mention that the
data for the interior is not very good because there wasn't
much data available when the book was published.  All things
considered it still seems extremely early for Short-billed
Dowitcher but certainly not impossible and I agree that the
possibility shouldn't be ruled out just because it's
unprecedented.  I've been looking hard at Dowitchers at
Island Park Reservoir for the past five years or so and I've
learned that Short-billed is far more regular than you would
think from the available data and I've seen birds that
showed characteristics of both the Pacific race (cuarinus)
and the central Canadian race (hendersoni).

I wouldn't bet the ranch on it but I'm fairly confident that
these birds are all Long-billed Dowitchers.

Cliff


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