The Ruff is a type of Sandpiper. The male bird has an amazing ability to fluff up his neck feathers like an enormous ruff (collar - see above) to impress a female. Plainer female is on far right above.
Outside of the breeding season, males have similar plumage to females and large flocks will gather to migrate from Northern Eurasia to Africa. In the breeding season, their are four types of plumage: males with black or red-brown ruffs (above left: can be plain, striped or mottled) which will claim a territory; males with a white ruff (satellites) which will occupy territory held by another male; males with the patterned male plumage but no ruff nor orange face and with brown head/neck which will live among (and mate with) females; and the females which have plain plumage.
Blonde neck and black ruff