[NatureNS] Short-billed Dowitcher photos (long, and a challenge)

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From: Richard Stern <sternrichard@gmail.com>
Date: Sun, 22 Jul 2012 10:24:33 -0300
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Hi Rick,

As I haven't seen any other reply, I'll have a go, and at the same time go
through the process, which might be more educational to people than a one
word answer. So with Dowitchers, no question that there all kinds of ID
difficulties, but if you work through it methodically (and the photos
really help) you can usually come to a conclusion ......

The bird has a relatively flat back, very little rusty color on the
underparts, doesn't really have barred sides of the breast, and more
importantly is in salt water habitat in July (as against brackish, marshy
habitat in November) so the odds are 99.9% that it's a Short-billed, not a
long billed (don't rely on bill length - it's irrelevant, and the birds are
poorly named for field ID purposes).

Then, as with any difficult shorebird, try and decide whether it's in adult
breeding, winter, or juvenile plumage. This bird is in worn adult plumage,
with an irregular, worn and "dirty" look to the uppersides. If the bird
were in juvenile plumage, that would make it easier to distinguish from
juv. Long-billed. However, it does make it easier to distinguish the 3
races of Short-billed. Most of S-B Dowitchers in NS would be griseus, which
has relatively little rusty on the breast, and which this bird looks to me
like it fits perfectly. The more central race, hendersoni, looks like a
Long-billed, and the westerly race, which migrates down the W. coast, also
looks more like a long-billed. I suspect that in true juv. or adult winter
plumage, however, the 3 races would be pretty indistinguishable in the
field.

So for these reasons I believe the bird in the photos is a worn adult
breeding-plumaged Limnodromus griseus griseus, which would likely comprise
the vast majority of all the dowitchers in NS in July. A side-on picture in
flat lighting to really illustrate the pattern of spotting and barring, and
the extent of rusty on the breast/ belly, would be better however for this
purpose.

I should add that years ago in July 2 dowitchers landed on the bridge of a
whale-watching boat in thick fog off Brier Island. I was very struck by the
extent of bright rusty on the underparts, but that they didn't have the
dense breast barring of Long-billed. So I wondered if they were hendersoni
Short-billed, and indeed that was confirmed when people far more
knowledgeable than I saw the pictures.

Now the challenge  ........ Someone please tell me if I'm wrong!!

Richard

On Sat, Jul 21, 2012 at 6:35 PM, Rick Whitman <
dendroica.caerulescens@gmail.com> wrote:

> I got some pretty definitive photos of one Short-billed Dowitcher
> today, on the point S of East Point at N. Grand Pre. A series of four
> starts at the direct link.
>
>
> http://rickwhitman.smugmug.com/Nature/Shorebirds/22686725_mPvQtv#!i=1978968974&k=5rZSPtj
>
> I'm hoping that Susann Myers or anyone can give me the race ID from these.
>
> Rick Whitman
>



-- 
#################
Richard Stern,
Port Williams, NS, Canada
sternrichard@gmail.com
###################

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Hi Rick,<br><br>As I haven&#39;t seen any other reply, I&#39;ll have a go, =
and at the same time go through the process, which might be more educationa=
l to people than a one word answer. So with Dowitchers, no question that th=
ere all kinds of ID difficulties, but if you work through it methodically (=
and the photos really help) you can usually come to a conclusion ......<br>

<br>The bird has a relatively flat back, very little rusty color on the und=
erparts, doesn&#39;t really have barred sides of the breast, and more impor=
tantly is in salt water habitat in July (as against brackish, marshy habita=
t in November) so the odds are 99.9% that it&#39;s a Short-billed, not a lo=
ng billed (don&#39;t rely on bill length - it&#39;s irrelevant, and the bir=
ds are poorly named for field ID purposes).<br>

<br>Then, as with any difficult shorebird, try and decide whether it&#39;s =
in adult breeding, winter, or juvenile plumage. This bird is in worn adult =
plumage, with an irregular, worn and &quot;dirty&quot; look to the uppersid=
es. If the bird were in juvenile plumage, that would make it easier to dist=
inguish from juv. Long-billed. However, it does make it easier to distingui=
sh the 3 races of Short-billed. Most of S-B Dowitchers in NS would be grise=
us, which has relatively little rusty on the breast, and which this bird lo=
oks to me like it fits perfectly. The more central race, hendersoni, looks =
like a Long-billed, and the westerly race, which migrates down the W. coast=
, also looks more like a long-billed. I suspect that in true juv. or adult =
winter plumage, however, the 3 races would be pretty indistinguishable in t=
he field.<br>

<br>So for these reasons I believe the bird in the photos is a worn adult b=
reeding-plumaged Limnodromus griseus griseus, which would likely comprise t=
he vast majority of all the dowitchers in NS in July. A side-on picture in =
flat lighting to really illustrate the pattern of spotting and barring, and=
 the extent of rusty on the breast/ belly, would be better however for this=
 purpose.<br>

<br>I should add that years ago in July 2 dowitchers landed on the bridge o=
f a whale-watching boat in thick fog off Brier Island. I was very struck by=
 the extent of bright rusty on the underparts, but that they didn&#39;t hav=
e the dense breast barring of Long-billed. So I wondered if they were hende=
rsoni Short-billed, and indeed that was confirmed when people far more know=
ledgeable than I saw the pictures.<br>

<br>Now the challenge=A0 ........ Someone please tell me if I&#39;m wrong!!=
<br><br>Richard<br><br><div class=3D"gmail_quote">On Sat, Jul 21, 2012 at 6=
:35 PM, Rick Whitman <span dir=3D"ltr">&lt;<a href=3D"mailto:dendroica.caer=
ulescens@gmail.com" target=3D"_blank">dendroica.caerulescens@gmail.com</a>&=
gt;</span> wrote:<br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex">I got some pretty definitive photos of one S=
hort-billed Dowitcher<br>
today, on the point S of East Point at N. Grand Pre. A series of four<br>
starts at the direct link.<br>
<br>
<a href=3D"http://rickwhitman.smugmug.com/Nature/Shorebirds/22686725_mPvQtv=
#%21i=3D1978968974&amp;k=3D5rZSPtj" target=3D"_blank">http://rickwhitman.sm=
ugmug.com/Nature/Shorebirds/22686725_mPvQtv#!i=3D1978968974&amp;k=3D5rZSPtj=
</a><br>


<br>
I&#39;m hoping that Susann Myers or anyone can give me the race ID from the=
se.<br>
<span class=3D"HOEnZb"><font color=3D"#888888"><br>
Rick Whitman<br>
</font></span></blockquote></div><br><br clear=3D"all"><br>-- <br>#########=
########<br>Richard Stern, <br>Port Williams, NS, Canada<br><a href=3D"mail=
to:sternrichard@gmail.com" target=3D"_blank">sternrichard@gmail.com</a><br>=
###################<br>



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