The Greater Yellowlegs is a long-legged shorebird that is a resident of the Western Hemisphere. Most birds of this species winter from Mexico to the southern tip of South America. A smaller population winters along the coasts of the contiguous United States. In Edmonds, the best place to see this species is in the marsh during its protracted migration. Look for its deep yellow legs.
The habitat that the Greater Yellowlegs favors includes mudflats, marshes, streams, ponds, tidal flats, estuaries and open beaches. On its northern breeding grounds it can be found in wooded muskeg and in spruce bogs.
In winter and migration, the Greater Yellowlegs forages on snails, crustaceans, tadpoles and marine worms. It also eats small fishes. During its breeding season, this shorebird feeds mostly on insects and their larvae. It forages actively in shallow water, sometimes running after minnows. It also feels for prey by walking forward, swinging its head back and forth with the tip of its bill under water.
Courtship displays take place on the northern breeding grounds in Canada and Alaska. The male repeatedly will rise on his wings and then fall with flutters and glides and whistle a loud ringing song. The nest is on the ground, usually close to water and often near a log or other object. It is no more than a shallow depression, sparsely lined with grass or leaves, and is well concealed in a hummock of moss.
There are usually four eggs that are probably incubated by both parents. Incubation lasts about 23 days. The young leave the nest soon after hatching. They find their own food but both parents tend the hatchlings by attacking or distracting predators. Age of the young at first flight is thought to be about 18-20 days.
According to the North American Breeding Bird Survey, the Greater Yellowlegs population has increased between 1966 and 2014. Population estimates are quite variable because this is one of the least-studied shorebirds in North America. Although it is common and widespread, it is found in low densities and its breeding grounds are inhospitable. Researchers apparently are not drawn to the mosquito-plagued muskegs. This is a species of least concern for conservation purposes.
You can hear the calls of a Greater Yellowlegs here: http://www.xeno-canto.org/207799.
— By Carol Riddell
Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.