THE SPOTTED SANDPIPER
by
Walter L. Meagher
Photos by Wayne Colony
Used to seeing sandpipers move to and fro as foaming waves run up and fall back on sandy shores of Long Island and New Jersey, the identity of the bird was firmly imprinted on my mind. Habitat: seaside. Habit: foraging in a group. Food: marine invertebrates. These ideas were firmly upended in El Charco where the Spotted Sandpiper is far from the sea and its numbers are few. See them on the mud flats when the presa is receding in company with Mexican ducks, or look for them near the wall of the Xichu Road. Best of all, look for one or two feeding in a characteristic crouch in absolute solitude on a big boulder beside the arroyo, below the dam. In El Charco, the Spotted Sandpiper enjoys solitude on slippery boulders and a moderate amount of company on squishy mudflats. It likes both.
There are tribal chieftains in Chad and Niger with 100 wives, or more. Polygamy has endured in various cultures for ages. The biology is simple enough: one male can impregnate many females; once a female conceives, she leaves the mating pool. To pass on his genes, it pays a male to impregnate as many females as he can. This is true for many animals, and some birds, but the Spotted Sandpiper female is polyandrous. Polyandry is not common among birds; indeed, it occurs in less than one percent of all bird species.
Early in the summer season, returning from winter quarters, females arrive first on insect-rich breeding grounds. Males are scarce. As a result, females fight for their service. Breeding, egg-laying and rearing nestlings is speeded up, placing greater demands on males.
During the six-to-seven week breeding season she can lay up to five complete clutches of four eggs each. The male sits on the eggs, thus removing himself from the chance of a second copulation. Driven by the potency of her egg-laying capability, the female seeks another male. And another. Domesticity limits his ardor, but her freedom is the precondition of polyandry.
Seeing the Spotted Sandpiper below the dam in El Charco, I had no idea what kind of life these birds lived!
Adapted from Wild & Wonderful: Nature Up Close in the Botanical Garden, El Charco del Ingenio, San Miguel de Allende, Guanajuato. 2008.