Stiff-tailed duck

The stiff-tailed ducks, the genus Oxyura, are part of the Oxyurini tribe of ducks.

Stiff-tailed duck Temporal range: Early Miocene to present
Male white-headed duck, Oxyura leucocephala
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Tribe:	Oxyurini
Genus:	Oxyura Bonaparte, 1828
Type species
Anas rubidus (ruddy duck) Wilson, 1814
Species
Oxyura australis Oxyura jamaicensis Oxyura leucocephala Oxyura maccoa Oxyura vittata †Oxyura vantetsi
Key:   Oxyura vittata   Oxyura ferruginea   Oxyura maccoa   Oxyura leucocephala   Oxyura jamaicensis   Oxyura australis

All have, as their name implies, long, stiff tail feathers, which are erected when the bird is resting. All have relatively large, swollen bills. These are freshwater diving ducks. Their legs are set far back, which makes them awkward on land, so they rarely leave the water.

Their uncommon displays involve drumming noises from inflatable throat sacs, head throwing, and erecting short crests. Plumage sequences are complicated, and aging difficult. Plumage is vital for survival because of this animal's tendency to spend time in the water.

Taxonomy

The genus Oxyura was introduced (as a subgenus) in 1828 by the French naturalist Charles Lucien Bonaparte to accommodate a single taxon, Anas rubidus Wilson, 1814. This is now considered to be a synonym of Anas jamaicensis Gmelin 1789, the ruddy duck. The genus name is derived from Ancient Greek oxus, meaning "sharp", and oura meaning "tail".

The six extant members of this genus are distributed widely throughout North America, South America, Australia, Asia, and much of Africa.

Species

Genus Oxyura – Bonaparte, 1828 – six species

Common name	Scientific name and subspecies	Range	Size and ecology	IUCN status and estimated population
Blue-billed duck Male Female	Oxyura australis Gould, 1837	Australia	Size: Habitat: Diet:	LC
Ruddy duck Male Female	Oxyura jamaicensis (Gmelin, 1789)	North and South America (+ British Isles, France, & Spain (introduced))	Size: Habitat: Diet:	LC
Andean duck Male Female	Oxyura ferruginea (Eyton, 1838)	Andes Mountains of South America	Size: Habitat: Diet:	LC
White-headed duck Male Female	Oxyura leucocephala (Scopoli, 1769)	Spain, North Africa, and western and central Asia	Size: Habitat: Diet:	EN
Maccoa duck Male	Oxyura maccoa (Eyton, 1838)	eastern Africa from Sudan and Ethiopia to Tanzania and west to eastern Zaire, and southern Africa from Zimbabwe to Cape Province, South Africa	Size: Habitat: Diet:	EN
Lake duck Male Female	Oxyura vittata (Philippi, 1860)	central Chile, Argentina and southern Uruguay	Size: Habitat: Diet:	LC

A fossil species from the Late Pliocene or Early Pleistocene of Jalisco (Mexico) was described as Oxyura zapatanima. It resembled a small ruddy duck or, even more, an Argentine blue-bill. A larger Middle Pleistocene fossil form from the southwestern United States was described as Oxyura bessomi; it was probably quite close to the ruddy duck.

"Oxyura" doksana from the Early Miocene of Dolnice (Czech Republic) cannot be assigned to any anatine subfamily with certainty.

Further reading

• Worthy, Trevor H.; Tennyson, A.J.D.; Jones, C.; McNamara, J.A. & Douglas, B.J. (2007): Miocene waterfowl and other birds from central Otago, New Zealand. J. Syst. Palaeontol. 5(1): 1-39. doi:10.1017/S1477201906001957 (HTML abstract)