Undulating wave of birds
Story and photos by Anita Westervelt, South Texas Border Chapter
We’ve all seen it. Droves of early morning blackbirds, exiting thorn forests in undulating waves, heading off to feed in the fields and beyond. A similar ballet is seen in the cities as grackles, on some ancient mysterious cue, burst from neighborhood trees for feeding destinations known only to the birds.
On a much smaller scale, I’m privy to private, diamond-shaped aerial formations in winter by some 30 small buff-colored birds that jet along the length of the resaca at intervals. After take-off, like a rehearsed maneuver, the birds dip one wing toward the water, the other skyward, showing their brown uppers. In a coordinated quick flip, flashes of silver suddenly glint as the sun winks off their white underparts; an instant later, the configuration rolls back and the birds land at the edge of the water.
Mentally, I would dub these shorebirds as sanderlings or peeps. This year, I captured a photo good enough to identify them via www.iNaturalist.org.
They are least sandpipers. I was correct in labelling them shorebirds and peeps – peeps being the common name for the five smallest species of North American sandpipers, although I did not know that. The classification of shorebirds designates a diverse group of birds in the order Charadrilformes – which includes sandpipers, plovers, avocets and phalaropes. There are approximately 217 recognized species of shorebirds in the world, 81 of which occur in the Americas for all or part of their lifecycle.
The least sandpiper is the smallest shorebird in the world, weighing about one ounce and measuring five to six inches long, males being slightly smaller than females. They are long-distance migrants, leaving their breeding grounds across northern North America to spend their winters in small groups along the edges of both United States coasts, the southern portion of the Gulf states and south. They are usually found on inland mudflats, bogs, marshes with open areas, flooded fields and sandy beaches, although they are not common on ocean beaches.
We only see least sandpipers in their winter plumage, grey-brown upperparts and white underparts. The bill is blackish, short, thin and slightly downcurved. Their legs are yellowish green. Least sandpipers forage mostly on mudflats and the edges of water bodies by walking slowly, head lowered and picking from the surface of the water or ground and sometimes probing in mud for food. Their diet includes tiny crustaceans, mollusks, aquatic insects, snails, marine worms and seeds.
Although there is no official collective noun for least sandpipers, a group of sandpipers is described as a bind, contradiction, fling, hill or time-step. Sanderlings, in the sandpiper family and a stairstep larger than least sandpipers, are referred to as a grain of sanderlings.
In reference to the opening lines of this article, undulating waves of a conglomerate of thousands of starlings, grackles, cowbirds and red-wing blackbirds, in synchronized acrobatic displays, is called a murmuration, named for the sound of the wingbeats and soft bird calls. It is thought that coordinated flock maneuvers camouflage plumage and confuse predators.
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