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

DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
Date: Sun, 22 Jul 2012 12:34:23 -0300
From: Rick Whitman <dendroica.caerulescens@gmail.com>
To: naturens@chebucto.ns.ca
Precedence: bulk
Return-Path: <naturens-mml-owner@chebucto.ns.ca>
Original-Recipient: rfc822;"| (cd /csuite/info/Environment/FNSN/MList; /csuite/lib/arch2html)"

next message in archive
next message in thread
previous message in archive
Index of Subjects


Thanks Richard, nicely done. I suspect the case is closed.

I might have mentioned yesterday that at that same location I
witnessed my first Peregrine Falcon attack of this season. There were
300 Semipalmated Sandpipers, which I was studying one by one, but they
all left in a very tight ball & they did not reappear on that high
tide.

Rick.

On Sun, Jul 22, 2012 at 10:24 AM, Richard Stern <sternrichard@gmail.com> wrote:
> 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
>

next message in archive
next message in thread
previous message in archive
Index of Subjects