The harlequin duck (Histrionicus histrionicus) is a small sea duck. It takes its name from Harlequin (French Arlequin, Italian Arlecchino), a colourfully dressed character in Commedia dell'arte. The species name comes from the Latin word 'histrio', meaning 'actor'. In North America it is also known as lords and ladies. Other names include painted duck, totem pole duck, rock duck, glacier duck, mountain duck, white-eyed diver, squeaker and blue streak. Adult breeding males have a colorful and complex plumage pattern. The head and neck are dark slate blue with a large white crescent marking in front of the eye that extends up to the crest, a small round dot behind the eye, and a larger oval spot down the side of the neck. A black crown stripe runs over the top of the head, with chestnut patches on either side. A black-bordered white collar separates the head from the breast. The body is largely a lighter slate blue with chestnut sides. A black-bordered white bar divides the breast vertically from the sides. The tail is black, long and pointed. The speculum is metallic blue. The inner secondary feathers are white and form white markings over the back when folded. The bill is blue-grey and the eye is reddish. Adult females are less colourful, with brownish-grey plumage with three white patches on the head: a round spot behind the eye, a larger patch from the eye to the bill and a small spot above the eye. (Source: Wikipedia.org, CC BY-SA)