Archive for September, 2017

A Tale of Two Semipals 9/24/17

Here we’ve got two small and abundant shorebirds both with the word semipalmated in their name, but one’s a sandpiper and the other is a plover. In each case, semipalmated refers to a bit of webbing between their toes. Sandpipers are a huge group of birds including snipe and curlews, while plovers are a much smaller collection that also contains Killdeer and lapwings. Together plovers and sandpipers make up a larger group called shorebirds. In general, plovers are chunkier with short bills and they forage by sight while the sandpipers find invertebrates by probing the mud or sand with their sensitive bills of varying lengths. While foraging, plovers run and pause, whereas sandpipers noodle around almost nonstop. Plovers are also masters of distraction, famous for their broken wing or “look at my fake nest” deceptions that lure predators away from their young or eggs. Both of these are juves, adult Semipalmated Plovers have a darker solid band across the breast and you’ll see quite a bit of orange at the base of the bill.


Baird’s and Semipalmated Sandpiper juves 9/19/17

Over on the right is our ubiquitous Semipalmated Sandpiper juve, a little blurry perhaps but which I’ve included to contrast the much less common (and more golden) Baird’s Sandpiper. Check out how extra-long its wings are, and how heavy the streaking in its breast is compared with the Semipal, which has no streaks or even any coloration crossing the center of the breast. Also note the white edged scapular feathers on the back and wing of the Baird’s—again one of the fieldmarks of juvenile sandpipers, as are the puffy white lores at the base of the bill. Baird’s Sandpipers mostly migrate from the Arctic down the central flyway, but every year some come down the Atlantic.


Semipalmated Sandpiper adult v juve 9/12/17

I know I just posted a Semipalmated Sandpiper last time, but that was a juve, and here I’ve got an adult in the foreground with a juve in the back to contrast them. The juve is paler backed, a little more golden in certain light, the head marking have more contrast and seem cleaner, while the adults back feathers are much darker and more worn. Besides the juve’s back and wing feathers having a prominent white edging, note also its lores, the prominent white spot at the upper base of the bill. That’s something you see in other juve sandpipers, but the same spot in an adult isn’t at all distinctive. We see migrating adult Semipals starting in July, juveniles are later and into the fall, but in mixed flocks you’ll often see both age groups in late August and September. Once you’re familiar with the 2 Semipal plumages, and these are the most abundant of the small sandpipers migrating through right now, then you can more easily spot the slight variations that distinguish some of the less common but similarly sized sandpipers, like the more golden and long-winged Baird’s, or the grayer and long-winged White-rumps, or the rare (for here) Western Sandpiper—the Semipal’s Pacific coast counterpart.


Semipalmated Sandpiper juve 9/7/17

If you are somewhere along on the East Coast and are baffled by the nuances of shorebird identification, this is the bird to learn first. It’s by far and away the most abundant and plainest sandpiper during fall migration and by knowing this bird and the adult form, you can more readily spot the nuances to help distinguish the other less common sandpipers. They have dark bills, dark legs, plain tan and brown tones above, some faint streaks and color across the breast, and wingtips shorter than the tail. And they’re small. Semipalmated Sandpipers are one of the 5 “peeps,” which is an unscientific term referring to the smallest sandpipers (some sandpipers like curlews are quite huge). I’ll post an adult soon, but the most important thing to distinguish juve from adult is that generally all juvenile shorebirds have a lacy white edging to their back and wing feathers, that’s lacking in adults. Adult plumage during migration will often look worn and tattered, and some migrating adults will have already molted into the solid grays of winter plumage, or be starting to well before the juves do. Semipalmated refers to having partially webbed feet.


Least Sandpiper juve 9/5/17

As its name implies, the Least is the smallest of the sandpipers. This one is hunkering down while a peregrine passes overhead, chasing a small flock of shorebirds it had flushed on the other side of the point. Adult Least Sandpipers are duller, the bright rusty reddish tones in the wings and back, along with the white edged scapular feathers are what distinguish this one as a juvenile. Leasts are quite common,

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