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Friday, 21 September 2012

More direction on SEMIPALMATED/WESTERN SANDPIPER identification with specific reference to the Hoylake juvenile WESTERN

I've quickly put up a page of some juvenile Semipalmated Sandpipers photographed in southern Ontario and New York State that can be viewed here:


http://www.flickr.com/photos/jmpawli10/

These birds are pretty bright overall (to be expected for mid-August), and show some range of plumage and bill length/shapes that are typically encountered on the eastern Great Lakes.

Jim Pawlicki
Buffalo, NY

I think commentators are being a bit too black and white by characterizing female Semi bills as long and straight, since there is incredible variation in Semi overall bill shape and bill tips, as this photo of a bunch of "typical" Semis in spring shows.

http://www.kevinkarlsonphotography.com/gallery/v/Shorebirds/Sandpipers/Peep/Semipalmated+Sandpipers+and+Sanderling_+May_+NJ+web.jpg.html.

The center bird is one of the troublesome Semis that show a long, drooping, fine-tipped bill that I never saw while working in the Alaskan Arctic for four years. This is an Eastern trait, and the bird behind the Sanderling is another female with a fine, drooping tip. The bird three from the left in the rear has a ridiculous drooping tip for a Semi, and not too long either. While I agree that more female Semis have long, straight bills, this sample group shows how many can show the long, fine, drooping tip as well, and often more fine-tipped than male Westerns. Several of the reported Semis from Great Britain look like Westerns to me, and this photo may shed some more light on their structural differences as well.

Kevin Karlson

For the sake of comparison, here are links to ID photo galleries for both Semipalmated and Western Sandpipers that appear in our online field guide that we've created (www.birdfellow.com). There are several images of juveniles in each gallery. I would direct your attention to images #18-30 in the Western Sandpiper gallery. These juveniles were all photographed during September. I think most of you will agree that many look just like the birds in the photos that Lee has shared. As you scroll through the thumbnails, click on the thumbnail of the image that you want to see and it will fill the larger featured image box on the right hand side of the page. By rolling your mouse cursor over the feature image, the caption will appear. If you then click a second time on the larger feature image on the right it will be enlarged to full size.

One thing to pay attention to is how much lighting and angle affect the apparent contrast between the scaps and coverts. Though rusty margins are evident on the scaps of all of these Westerns, the degree of contrast is highly variable in this series of images.

http://www.birdfellow.com/birds/semipalmated-sandpiper-calidris-pusilla#/idPhotos

http://www.birdfellow.com/birds/western-sandpiper-calidris-mauri#/idPhotos

I hope that you find these galleries useful.

Dave Irons
Content Editor www.birdfellow.com