A yellow-legged shorebird that often wades in deeper water than many other sandpipers.
Its long yellow legs and sturdy, relatively long bill stand out. It is bulkier and longer-billed than the similar Lesser Yellowlegs.
It breeds in northern Canadian wetlands and forages on mudflats and shallow marshes during migration. Some winter in marshes across the southern United States.
It nests in a moss or peat hollow on the ground, often beside a low conifer, sometimes lined with leaves or lichen. Clutches have 3–4 eggs, incubated for about 23 days. Downy chicks leave within hours and feed themselves.
It catches aquatic invertebrates with rapid stabs at the surface of shallow water, also taking small frogs and fish.
It often forages alone and forms loose groups on migration. At night it roosts in dense flocks with other shorebirds.
The thick-based bill turns slightly upward. It has a white eye-ring; juveniles are browner above with crisp markings. In flight the rump is white and the wings are plain.
An extinction-risk assessment has not been added yet.