Looking at the photos that are included with Stacy Meyerheinrich's eBird
checklist (link below) I would suggest the observers reconsider the ID. IMO
this bird is very clearly a Dunlin, as proposed in a follow up posting by
Steve Walter.

http://ebird.org/ebird/view/checklist/S39350964

Dunlins with very long and slightly decurved bills are typical of the North
American subspecies, particularly *C. a. hudsonia* ('Hudsonian Dunlin'),
which breeds in the central Canadian arctic and is the predominant migrant
through coastal NYS. Individuals are frequently mistaken for Curlew
Sandpiper, in large part because bill length is especially pronounced in
females.

When identifying shorebirds it's important to establish the age of the bird
as this influences feather details, which can be critical. This bird looks
to be transitioning into first basic plumage (i.e., first fall). Few of the
upper part feathers (scapulars, wing coverts) have pale edging as would be
expected for juvenile plumage; these edges have already abraded. The
centers of the grayer feathers have a short dark central vein, this dark
line is longer and often more prominent in Curlew Sands.

Note also the very short supercilium (a characteristic feature of Hudsonian
dunlin) which is limited to a pale arc above they eye. In Curlew Sandpiper
this usually extends further forward and behind relative to the eye.

As for the absence of dark central upper tail coverts ('white rump'), I've
always found this is exceptionally difficult to assess with accuracy in the
field. It's a negative mark, meaning you are hoping to see something that's
not there. The central line could be hidden by the way the feathers are
folded over each other. Although touted as a key mark in the field guides,
Curlew Sandpipers often have dark spots and darker feathers peaking through
so this is a very problematic field mark. Best ignored in favor of feather
details (as discussed above) and structure such as leg length.

Returning to the Jones Beach bird, the photos aren't ideal to assess
uppertail coverts. There are hints of dark but I'm not sure exactly which
feathers are involved. Certainly the images don't prove this point.

You can read more about this reoccurring ID challenge in a feature I posted
on OceanWanderers.com, many years, and many miles, ago.

http://www.oceanwanderers.com/BSmallSHorebird.html

Anyhow, sorry to  throw water on the sighting. Regardless its always
instructive to take a close, hard look at interesting birds and we should
thank Stacy for getting the photos on line so quickly.

Angus Wilson
NYC/Springs, NY

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