Male - The male Lake Duck in breeding season has a deep chestnut body, a black head and neck, a blue beak, brown eyes, whitish abdomen, grey tail, dark-brown wings, and the legs and feet are dark grey. In waterfowl, the eversion mechanism is lymphatic, and the unusual length of the structure relative to its width prohibited pulling the entire length of the organ inside out. Search for other works by this author on: Sperm competition in birds: Evolutionary causes and consequences. Dissection and preparation of the Argentine Lake Duck's penis reveal a massive structure (approximately equal in length to the Ostrich penis) with a peculiar array of dense spines running the entire length of the organ. Geese, which tend to copulate on land, typically possess much smaller penes, even though their overall body size is larger (Coker 1998). Carcasses subsequently were placed on ice, frozen, and exported to the Louisiana State University Museum of Natural Science (LSUMNS). The Argentine lake duck has something to quack about. Handbook of Australia, New Zealand, and Antarctic birds. Download this stock image: Argentine Lake Duck, male / (Oxyura vittata) / Argentine Blue-bill, Argentine Ruddy Duck - X6MN68 from Alamy's library of millions of … The testes of birds undergo substantial changes in size, often enlarging greatly during the breeding season and then shrinking to become almost invisible (Witschi 1935, Wingfield and Farner 1980). Like other stifftails (Nomonyx and Oxyura), the Argentine Lake Duck is nested within a clade of promiscuous, dichromatic congeners that share many derived social and morphological characters (McCracken et al. Carcasses were thawed three months later and prepared as museum skins (n = 6) and a skeletal specimen (n = 1). The lake duck's penis is corkscrew-shaped and retracts into the abdomen when not required. North American scientists have discovered the longest bird penis ever - a 42.5cm organ belonging to a duck. S. R.Derrickson, and So, let's review: At the base if the argentine lake duck cock, there is a crown of thorns, followed by a spiralling, corkscrewing, pig-like shaft covered in spines and spikes, followed by a broom. Male dinosaurs must have had the equipment for internal fertilization. The Argentine Blue-bill or Argentine Lake Duck (Oxyura vittata) can have 42.5 cm (17 inches) long penises, at an average body length of 20 cm (8 inches)! Each individual possessed a large, well-developed cloacal swelling ventral to the base of the tail (Fig. At maximum extent, the everted penis can be no longer than one-half the circumference of the loop, or a distance equivalent to the distance from the base to the head of the loop (see Fig. Other birds lack sperm ducts in their penes, and instead rely on spiral grooves to channel the flow of sperm. obs., R. B Brau pers. Møller Eds. Try to imagine that on a human male, and for the sake of context, imagine it being about eight feet long. Academic Press, London. 1A). King 1981, Briskie and Montgomerie 1997). R. T.Alisauskas. Dunn, Each of the five birds that I dissected appeared to be in breeding condition, as indicated by a bright blue bill, black head, and ruddy breeding plumage. Like other ducks, in order for fertilization to occur, the male lake duck inserts his penis (sometimes called the male intromittent organ) into the female's oviduct, and sperm travels up the penis to fertilise the female. Genitalia and testes subsequently were fixed in 10% formaldehyde, preserved in 70% ethanol, and deposited at the Louisiana State University Museum of Natural Science. Hochbaum 1942). Mass (± 50 g) of each bird was measured at the time of collection. Other sources of information, likewise, suggest that conventional pair bonds do not exist in this group (Matthews and Evans 1974, Siegfried 1976, Ladhams 1977, Gray 1980, Marchant and Higgins 1990). 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