Sexual competition has endowed ducks with enormous organs | Science Illustrated
White-headed Duck (Oxyura leucocephala) adult male, biting extended penis after mating, on water (captive) - SuperStock
White-headed Duck (Oxyura leucocephala) male on water, pulling penis with its beak after mating, captive Stock Photo - Alamy
Our Duck Penis Problem - The Wisdom Daily
Lake duck - Wikipedia
Sexual Competition among Ducks Wreaks Havoc on Penis Size - Scientific American
Why are duck penises corkscrew-shaped and how do they mate? | BBC Science Focus Magazine
When growing their penises for the season, ducks bend to social pressure
Duck Penises Grow Bigger Among Rivals
This Is How Ducks Have Sex And It's Pretty Incredible
Duck Penises Get Bigger When They Are Surrounded By Other Males
Science News - Freaky Friday Lake ducks The male lake duck is in the 3% of birds that have penises. More curiously, it has the longest penis of all vertebrates in comparison
Ballistic Penises and Corkscrew Vaginas: The Sexual Battles of Ducks | Discover Magazine
Social environment matters for duck penis size - BirdGuides
Duck with Prolapsed, Gangrenous Penis Gets a Trim - YouTube
Evidence of phenotypic plasticity of penis morphology and delayed reproductive maturation in response to male competition in waterfowl
Photograph of the 42.5-cm penis of a male Argentine lake duck (Oxyura... | Download Scientific Diagram
OMGFacts - Argentine lake ducks can have penises of up to 17 inches in length—the largest of any known bird. | Facebook
Argentine ruddy duck / Argentijnse stekelstaarteend
Pacific Black Duck Penis | Displaying its penis. Lake Wendou… | Flickr
Bird penises are fascinating. Wait, where are you going? | Grist
Found! The longest bird penis ever › News in Science (ABC Science)
Argentine ruddy duck / Argentijnse stekelstaarteend
There is a Type of Duck That Sometimes Lassos its Potential Mates with its Penis
Twisted Duck Sex
