[CT Birds] juvenile shorebirds
ctgregh at yahoo.com
Mon Aug 10 19:02:34 EDT 2015
Nick Bonomo noted that juvenile shorebirds are starting to show up. Today at Shell Beach in Guilford Bruce Finnan and I had a single juvenile Short-billed Dowitcher and about 4 juvenile Least Sandpipers, which were all of the Leasts we found among 200+ Semipalmated Sandpipers. The Semis were virtually all adults. I only found one definite juvenile. But they'll be here soon.
For those who don't get a lot chance to bird at the shore (or just find shorebirds daunting) its worth noting a few things about juveniles. First, somewhat counterintuitively, juvenile shorebirds are in many cases more colorful and generally more crisp looking than adults. The adults were in their finest plumage as they moved through CT on spring migration and arrived on the breeding grounds. By the time they've started heading south (some as early as late June and many on the move through July), they've begun to molt into basic (winter) plumage and are looking drabber and often messier. The juveniles, however, are in their first full set of feathers, bright and crisp with little wear. Unworn feather edges give many a scaly or scalloped look.
What about the juveniles just showing up now, even though adults have been on the move for more than a month? The answer is kind of amazing. Shorebirds like (chickens) have precocial young. Like baby chicks, they can run around on their own very soon after hatching, meaning adults don't have to care for them as long as birds with young that require a lot of attention before they can leave the nest. As a result, adult shorebirds are freed up to get a head start out of the Arctic, so they leave - and leave their young behind. How do those juveniles manage to undertake long migrations on their own, leaving the nesting grounds after adults are gone? They're hard-wired to undertake it on their own.
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