Outside the breeding season, the typical male's head and neck decorations and the bare facial skin are lost and the legs and bill become duller.
The upperparts are grey-brown, and the underparts are white with grey mottling on the breast and flanks.
Recent research suggests that its closest relatives are the broad-billed sandpiper, Calidris falcinellus, and the sharp-tailed sandpiper, Calidris acuminata.
a later name reeve, which is still used for the female, is of unknown origin, but may be derived from the shire-reeve, a feudal officer, likening the male's flamboyant plumage to the official's robes.
The final male breeding plumage results from the replacement of both winter and striped feathers, but the female retains the striped feathers and replaces only the winter feathers to reach her summer plumage.
In winter, her plumage is similar to that of the male, but the sexes are distinguishable on size.
Typical adult male ruffs start to moult into the main display plumage before their return to the breeding areas, and the proportion of birds with head and neck decorations gradually increases through the spring.
In the May-to-June breeding season, the typical male's legs, bill and warty bare facial skin are orange, and he has distinctive head tufts and a neck ruff.
These ornaments vary on individual birds, being black, chestnut or white, with the colouring solid, barred or irregular.