The so-called Stiff-tailed Ducks, in which the feathers of the tail are narrow and very stiff, constitute the subfamily Erismaturince, and are comprised in four genera and about a dozen species. Of these the Ruddy Duck (Erismatura jamaicensis) of temperate North America may be taken as a type. The male has the upper parts uniform reddish chestnut, with the top of the head black and the side of the head white, while the lower parts are silvery white. The female and young are grayish brown above, the plumage marked with fine wavy bars of buff; the species is about fifteen inches in length. This species frequents the salt ponds along the coast and is also found on the inland rivers and lakes. Its food, which is said to consist mainly of aquatic plants, is obtained by diving. It is usually a rather tame species, permitting the close approach of a boat, and on the water it makes rather a curious appearance, as it often carries the tail erect. While its main nesting ground is far north, it breeds locally throughout its range, placing the nest in a marsh and usually on a floating mass of vegetation. The six to ten eggs are creamy white in color. Other species are found in South America, Africa, and Australia.