#stiff-tailed ducks

[antiqueanimals]

Don Balke (American, b. 1933). Ruddy Ducks, 1981. Gouache and watercolor on board.

MutualArt

[a-dinosaur-a-day]

Oxyura

White-Headed Duck by Benutzer Else, CC BY-SA 3.0

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Name: Oxyura

Status: Extant

First Described: 1828

Described By: Bonaparte

Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae, Euavialae, Avebrevicauda, Pygostylia, Ornithothoraces, Euornithes, Ornithuromorpha, Ornithurae, Neornithes, Neognathae, Galloanserae, Anseriformes, Anseres, Anatoidea, Anatidae, Oxyurinae

Referred Species: O. australis (Blue-Billed Duck, extant), O. jamaicensis (Ruddy Duck, extant), O. ferruginea (Andean Duck, extant), O. leucocephala (White-Headed Duck, extant), O. maccoa (Maccoa Duck, extant), O. vittata (Lake Duck, extant), O. vantetsi (New Zealand Stiff-Tailed Duck, extinct), O. doksana (extinct), O. zapatanima (extinct), O. bessomi (extinct) 

Oxyura is a genus of extemely distinctive and, frankly, bizzare ducks from all over the world, known from an expansive fossil record of relatives as well as members of the genus. The stiff-tailed ducks appeared sometime in the Paleogene, and diversified extensively during the Miocene, with many members of the family found all over the globe - as we have seen here at ADAD. This genus in particular first appears in the Miocene, potentially in the Czech Republic, though that species is dubious. Other species are known from the Pliocene of Mexico, and the Pleistocene of the southwestern United States that might actually be an evolutionary precursor to the modern Ruddy Duck. The New Zealand Stiff-Tailed Duck, from the Holocene of New Zealand, was closely related to the Blue-Billed duck but one-tenth the size, and probably went extinct due to human overhunting. These birds are united in having long, stiff tail feathers that go up when the bird is resting, giving these dinosaurs a distinctive appearance. They have large, swollen bills, and are freshwater diving ducks. They have legs that are set far back, so they are very awkward moving on land, and thus rarely leave the water. They are found all over the world, as shown below: 

By Ninjatacoshell, CC BY-SA 3.0 (Red: Lake Duck, Yellow: Ruddy Duck, Green: Maccoa Duck, Turquoise: White-Headed Duck, Blue: Blue-Billed Duck) 

Though the ranges of each individual species rarely overlap. They have a lot of interesting displays, such as making drumming noises from throat sacs, throwing their heads, and popping up crests. They spend so much time in the water that their plumage is often the most important thing keeping them comfortable. 

Blue-Billed Duck by Valorix, CC BY-SA 3.0 

The Blue-Billed Duck, O. australis, is the only species known from Australia. They are fairly small, growing up to 40 centimeters in length. The males have blue bills that become very brightly colored during the breeding season, and also become ruddy brown at this time. The females have black feathers year round. These birds are not only the only member of the genus known from Australia, but only live in Australia, in temperate wetlands in large numbers. They seem to be near threatened, due to drainage of wetland systems, flood migration, and vegetation loss. There are conservations ongoing for the bird, including maintaining water flows. A shy species, it’s difficult to parse out much of its behavior in the wild - its average lifespan is unknown, though probably less than 10 years. They mature after 12 months from hatching, and many eggs are laid in a clutch. 

Blue-Billed Duck by Helena Bella, CC BY-SA 3.0 

Given that this is a stiff-tailed duck, it is a very awkward mover on land, having difficulty walking much like a penguin. They, thus, spend almost all their time in the water, in flocks of many hundreds far from the shore. They breed in deep, freshwater swamps, using dense vegetation for cover. During the breeding season the large flocks tend to disperse, with the females taking care of eggs and males only remaining for courtship. They dive under the water when threatened, and rarely fly. They are omnivorous birds, feeding on invertebrates, seeds, buds, and fruit. They sift through the mud with their beaks and feed primarily on small water animals like dragonflies, water beetles, and larvae. They seem to migrate from breeding swamps of the inland to rivers during the non-breeding season. They seem to have facultative brood parasitism, with females occasionally dumping their clutches in nests other than their own. The ducklings are of adult size at eight weeks, and are relatively independent upon hatching. 

Ruddy Duck by Dick Daniels, CC BY-SA 3.0 

The Ruddy Duck is the Stiff-Tailed Duck species known from North America, found throughout the United States and Mexico, even extending up into Canada, with a distinct subspecies population along the Pacific Coast of South America. They are considered not threatened with extinction. They are small duck, about 34 to 43 centimeters in length, with scoop-shaped bills and long stiff tails usually held above water. The males have brown bodies and bright blue bills like their Australian cousins during the breeding season, and females are brownish with grey bills. They have dark tops of the wings that are visible while flying, though they don’t fly often. 

Ruddy Duck by Dick Daniels, CC BY-SA 3.0 

These birds live primarily in marshy lakes and ponds, nesting in dense vegetation near the water. Females build nests out of grass, hiding it in tall vegetation from predators. They have about 5 to 15 ducklings per brood, and they are migratory birds following the range of unfrozen lakes and ponds. They’ll dive underwater to feed upon seeds, roots, insects, and crustaceans. Unfortunately, they are an invasive species in Great Britain, though efforts to remove their populations have bene mostly successful. 

Andean Duck by Milardello, in the Public Domain 

The Andean Duck is also known from the Andes Mountains in South America, and is also not threatened with extinction. They are small birds, with similar coloration to the other members of the genus. They have short, thick necks and slightly peaked heads, giving their round bills a superficially more normal appearance. They are more dull in the winter, with females being brownish year round. It’s face is all black, and it’s generally larger than the Ruddy Duck, making the two species distinct. They live in marshy lakes and ponds along the Andes Mountains, and nest in dense vegetation. They feed upon seeds, roots, insects, and crustaceans by diving into the water. 

Lake Duck by Dick Daniels, CC BY-SA 3.0 

The Lake Duck also exists in South America, entirely within the southern part of the continent, in the southern portions of Chile, Argentina, and Uruguay. They are not threatened with extinction. They live in lakes throughout this area and are notable for something very distinctive: they have the longest penis in relation to body length of all vertebrates, and the largest avian reproductive organ. The penis is coiled up when not erect, and when erect it is the same size as the animal (though usually is kept shorter). As these birds are very promiscuous, this penis probably evolved due to competitive pressure in mating, utilizing the length and shape to remove sperm from previous birds. Though they attempt to force copulation on the females, the females are able to control their bodies through their corkscrew vaginas, which prevent successful fertilization from coerced copulation. This rather violent mating system is, unfortunately, common to most ducks. 

Maccoa Duck by Sandy Cole, CC BY-SA 3.0 

The Maccoa Duck is the African species of this genus, and is unfortunately vulnerable to extinction. It is known in two areas - Sudan, Ethiopia, Zaire, and Tanzania; and then Zimbabwe and South Africa. They live in shallow fresh waters, as well as brackish and salty lakes during the winter. The males are brownish, with black heads and blue bills. The females have grey bills and black bodies. 

White-Headed Duck by Miss Tanya Love, CC BY-SA 3.0 

The White-Headed Duck is our final species, and the only one naturally known from Eurasia. It is found in Spain and North Africa, with very large populations in Greece, Western and Central Asia. They live in large bodies of open water such as lakes, ponds, and artificial water bodies, using dense aquatic plants for shelter and nesting sites. They dive and swim under water to feed on a variety of food items, and rarely fly. The females have dark bills and dull coloration, while the males are grey, with white heads and distinctive, fat-looking blue bills (the females also have the fat looking bill, it’s just grey). They are about 43 to 48 centimeters in length, making them rather long for the genus. Unfortunately, due to large reductions in populations from habitat loss, hunting, and the invasive ruddy duck, it’s considered endangered. Conservation efforts are ongoing. 

Sources: 

https://en.wikipedia.org/wiki/New_Zealand_stiff-tailed_duck 

https://en.wikipedia.org/wiki/Stiff-tailed_duck 

https://en.wikipedia.org/wiki/Blue-billed_duck 

https://en.wikipedia.org/wiki/Ruddy_duck 

https://en.wikipedia.org/wiki/Andean_duck 

https://en.wikipedia.org/wiki/Lake_duck 

https://en.wikipedia.org/wiki/Maccoa_duck 

https://en.wikipedia.org/wiki/White-headed_duck 

[archosaurophilia]

Oxyurin Odyssey

So, waterfowl. You might take your neighborhood mallards for granted as I often have, but waterfowl are really very cool. Yes, even the endless hordes of Canada geese blocking your commute, disgruntled American readers. The order Anseriformes contains something like 180 extant species, and just about all of them are outright fascinating. Today we'll zero in on a small clan of anatids known variously as the oxyurins, oxyurines, or the stiff-tailed ducks.

And here’s your yearly pittance, archosaurophiles.

[natureeuphoria-blog]

Ruddy Ducks on Lake Ontario at Humber Bay Park East, Toronto (Dark, cloudy April day, just before a storm)

The ruddy duck (Oxyura jamaicensis) is a duck from North America and the Andes Mountains of South America, one of the stiff-tailed ducks.

As a result of escapes from wildfowl collections in the late 1950s, they became established in the UK, from where they spread into Europe. This duck's aggressive courting behaviour and willingness to interbreed with the endangered native white-headed duck (Oxyura leucocephala), of southern Europe, caused concern amongst Spanish conservationists. Due to this, a controversial scheme to extirpate the ruddy duck as a British breeding species started; there have also been culling attempts in other European countries. By early 2014, the cull had reduced the British population to about 20–100, down from a peak of about 5500 in 2000.

http://www.theguardian.com/environment/2012/mar/08/ruddy-ducks-extermination

http://www.telegraph.co.uk/news/earth/wildlife/10626557/The-ruddy-ducks-with-nowhere-left-to-hide.html