Argentine Lake Duck
Oxyura vittata
22.3 cm (range 19 cm–24.5 cm) record 42.5 cm
Length of the inverted penis tube, base of cloaca to the bend of the loop (dissected)
Corkscrew, Spiny
In five dissected males the penis averaged 22.3 cm. The spines near its base are sharp; further along they turn soft and brush-like.
Margin note: The duck would like you to stop staring.
Sources
- McCracken K.G. (2000) The 20-cm spiny penis of the Argentine Lake Duck (Oxyura vittata). The Auk 117(3):820–825 doi:10.2307/4089612
- Brennan P.L.R., Clark C.J., Prum R.O. (2010) Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia. Proc. R. Soc. B 277:1309–1314 doi:10.1098/rspb.2009.2139
- McCracken K.G., Wilson R.E., McCracken P.J., Johnson K.P. (2001) Are ducks impressed by drakes' display? Nature 413:128 doi:10.1038/35093160
- Johnsgard P.A. (1978) Ducks, Geese, and Swans of the World. University of Nebraska Press. Tribe Oxyurini chapter (UNL DigitalCommons edition) link
Drawn from
- McCracken et al. 2001, Nature 413:128, Fig. 1: Photo of the 42.5 cm everted organ hanging from a dead male: a long narrow reddish tube twisted in a tight helix along most of its length, longer than the bird's body
- McCracken 2000, Auk 117:822, Fig. 1E–F: Tube proportions, taper, spine distribution (dissected, flaccid)
- McCracken et al. 2001, Nature, Fig. 1: Photograph of the everted 42.5 cm organ: helix along most of its length
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