Greater yellowlegs (Tringa melanoleuca)
This large shorebird is a member of the sandpiper group. With a length of 14 inches, it is distinguished from similar-size shorebirds by its yellow legs and slightly up-curved beak. A close relative, the lesser yellowlegs, has a shorter, straight beak and is several inches smaller. The individual pictured here is dressed for winter but will add to its side, breast and neck stripes for the spring mating season. Sexes are similar in size and coloration.
The greater yellowlegs is mainly a spring and fall migrant through south Puget Sound, but some may stay for the winter. Most will travel south along the West and East coasts of the United States and on to South America. The greater yellowlegs molts (the annual feather-renewal process) in an unusual pattern, beginning the molt on the breeding grounds, suspending it during migration and finishing on the wintering grounds.
It breeds in the far north at the edge of the coniferous forest in muskeg and tundra areas from Alaska through Canada. In May, it builds a simple nest on the ground, where it lays three to four eggs that hatch in 23 days. The young leave the nest within 24 hours of hatching and move away from the immediate area soon after.
It feeds in both freshwater and estuarine areas on a variety of small animals such as crustaceans, marine worms and insects, as well as fish. Foraging is done alone or in small flocks in which the birds skim prey from the water surface or swing their bills back and forth, seeking fish.
David W. Jamison is a marine biologist and Boston Harbor resident.