Semi What?
I was watching a flock of some kind of sandpipers speed-pecking away on the wet sand when suddenly a different bird erupted out of the scrum and dashed into an empty space where it could forage by itself. When I got it focused, I thought, “Long time no see! A Killdeer!” I hadn’t seen a Killdeer here since 2018 (“A Killdeer Visit,” Sep 29 2018). Actually, I had never seen this bird at all. But I had to get the images home to learn that. Just out of habit, I checked an image with Merlin, the almost-magic app that identifies birds from photographs, and Merlin said, “Semipalmated Plover.” A bit of homework and it became clear. Killdeer and this plover do look similar, but the Killdeer has two black bands around its neck, the SPP only one.
Before long, my lone plover found another, and then gradually a little flock of 12 materialized, darting around and away from the sandpipers and foraging within a range of a few feet from one another.
Males and females look very similar. Researchers who captured the birds and measured their wing length, the length of the streak of white above the eye, and the number of brown feathers in the breast still had a greater than ten percent error rate compared to molecular sexing. The sexes not only look similar, they perform similar work in sitting on the eggs during the more than three weeks between laying and hatching. The males, in fact, may do a bit more brooding than the females, and may stay around longer after they hatch. All this happens in shallow nests on gravel, sand, or mud in the near-Arctic zones of Canada during the brief summer. From there, the birds may fly as far as southern South America on both coasts for the winter. The little flock I saw undoubtedly were here on a rest stop during their northward migration.
With their stubby beaks, these plovers are no match for other shorebirds when it comes to extracting buried edibles from mudflats. Yet they manage adequately. A specialty of theirs is finding buried worms, some of them longer than the birds’ own bodies, and pulling them up. All I saw was them snatching up invisible bits on the surface or just below. They looked quite healthy and well-rounded, which is a good thing as they had more than 1,000 miles to fly.
I had to look up “palmated” to make sense of the name. Palmated in birds refers to webbing between the toes. Ducks like Mallards would be considered fully palmated because all their front toes are connected by webs that go the full length of the digit. You want that (or something equally good, like Coots have) for paddling if you’re a bird that lives on the water. The SPP has webbing between all three of its front toes, but the webbing doesn’t extend to the end of the toes; it’s quite shallow, and not much use for paddling. The SPP can swim short distances but is definitely not a waterbird; it’s a shorebird.
