Scientific name:
Oxyurini

Natural spread:
Africa, America, Asia, Australia

the rudder-ducks forms a rather strongly deviant group of the duck-birds. In particular, the beak is wide and high at the root and in front somewhat shovel-shaped upward bent, the "nail" at the beak-top is bent to a hook downward. The wedge-shaped tail, from 18 stiff and pointed feathers formed, a sure recognition-characteristic offers: When swimming, it can extend wheel-shaped and lifted up almost vertically on that occasion from the water is carried. The rudder-ducks always are near the water and dive very well.

Types, way of life The type of the rudder-ducks i. e. S. (Oxyura, puts most of the representatives of this group. The smallest rudder-duck is at all among them, the West Indian mask-duck (Oxyura Dominica). Mainly as stand-birds, the mask-ducks live in pairs during the day or in groups in the protection of water and shore-plants and only rarely appears on the free water-surface. Here, they pick up its food, that consists predominantly of water-plants. Only in the evening and night-hours, smaller flips are undertaken. Quite not usually in this group is its behavior with danger: they try to gain its coverage flying. Other types rarely fly up but swim very deeply, so that the head and the tail only protrude from the water or swim fast from it.

Despite the small, curved wings, most types nevertheless are good and fast planes if one refrains from a Peruvian subtype of the tail-head-rudder-duck (Oxyura jamaicensis), that can only move its high weight up to 4000 m in altitudes under difficulties through the air. Most types also are, in dependence on its spread-area, distinct migratory birds.

Shape With most types, the females and males differently are colored. Here, the white-back-duck (Thallassornis leuconotus) forms an exception. it is represented on the African continent. Often, the drakes position a more splendidly colored brood-dress to the incubation. The male of the Australian rag-duck (Biziura lobata), with its far behind sedentary legs and the especially powerful beak anyway a deviant form, distinguishes itself additionally through a loosely hanging, black gill. In Europe's Mediterranean-countries as well as in North-Africa and from the Kaspischen sea on eastward the white-head-rudder-duck (Oxyura leucocephala) is alive; 46 cm of length. As with the mask-duck, the drake is colored auburn in the incubation here; in the silence-dress, it however hardly differs from the mainly dun female. In this middle - and this type is West European countries a rare Irrgast.

Reproduction The nest of the white-head-rudder-ducks always is erected near the water, often on a small reed-island. The nests contain 6-13 eggs. Probably the female incubates the eggs alone and is responsible also for the youth-leadership. Exact statements are not to this available since the alto-birds immediately escape if one approaches the nest. However, the drake was observed in nest-proximity. Moreover, the white-head-rudder-ducks can dive under water up to two minutes. So, they collect also its food, that consists of water-plants and water-insects.

Cuckoo-duck The black-head-ducks (Heteronetta atricapilla) from the middle South America are the single brood-parasites among the duck-birds. The eggs are put into the nests of quite different host-birds, Z. B. into those of the Peposakaente (Netta peposaka), different Rallen, herons, seagulls etc.. Like the eggs of all rudder-duck-types, they have the quality to hold its own-heat long. The hatched chicks then join another duck-type.

Perform courtship display In general, the rudder-ducks are silent; with it, the drakes let perform courtship display hear a row of different reputations, however. As well, distinctive behaviors are perform courtship display familiar with it, Z. B. the "effervescence" of the males, at the air-blister with the beak from the neck-plumage is out-pressed or (tail-head-duck) "water-splashes" of direction of the female (rag-duck).