Pushy Peeps

A quick trip to the Green Valley sewage ponds this morning succeeded: one of the two recently reported Short-billed Dowitchers was feeding along the edge of the first pond, a nice bright tiger-tertialed juvenile. But then a big yellow machine appeared and started scraping the edges of the basin, and the bird flew, calling, into the next, lushly overgrown pond; I took this as my own cue to move on, too.

The rain puddles in the northwest pool are of a perfect size and depth for shorebirds, as a flock of more than 100 had discovered. There were Wilson’s Phalaropes, Black-necked Stilts, Killdeer, and a single Baird’s Sandpiper; but most of the birds scrambling around on the mudflat were peep, nearly 50 Western Sandpipers and a slightly smaller number of Least Sandpipers. As expected, almost all of the Westerns were juveniles, while the Leasts included both adults and this summer’s young.

With sandpipers as with so many other animals, it’s the little ones that have the biggest personalities. Many of this morning’s peep seemed to be spending as much time fighting as they did eating. I tried to figure out the “pecking order,” but it seemed that juveniles bullied adults as often as the other way around, and Leasts chased Westerns as often as the larger birds harrassed them.

For the most part, combat was limited to the usual posturing: crouched charges, uplifted tails, wings raised to show the white linings. But one of the Leasts wasn’t satisfied with ritual sparring, and instead kept pushing the other birds out of the way, bumping rudely into conspecifics and larger birds alike, at one point actually knocking a Western off balance! There must be a lot at stake out on those scummy flats.