Ornithologist Richard Prum on Duck Sex and Human Evolution - DER SPIEGEL
Duck penis plasticity – yes you read that right | The Waterthrush Blog
How the bird lost its penis
RareBirdAlertUK on Twitter: "Social environment matters for duck penis size #ornithology https://t.co/OJI876XEhB https://t.co/t9YVfe5eGh" / Twitter
Can Chickens and Ducks Live Together? - Happy Wife Acres
Ducks fight the battle of the sexes in their genitals | New Scientist
Duck Penises Grow Bigger Among Rivals
In Defense of Studying the Duck Penis - Pacific Standard
Duck penis controversy: NSF is right to fund basic research that conservatives misrepresent.
Why are duck penises corkscrew-shaped and how do they mate? | BBC Science Focus Magazine
Sexual Competition among Ducks Wreaks Havoc on Penis Size - Scientific American
Duck Penis Length Depends on Other Guys | WIRED
White-headed Duck (Oxyura leucocephala) adult male, biting extended penis after mating, on water (captive) - SuperStock
Special Announcement: April is D.P. Month! | Curious Cox
File:Duck Reproduction.svg - Wikipedia
In Ducks, War of the Sexes Plays Out in the Evolution of Genitalia - The New York Times
Twisted Duck Sex
Duck penises grow bigger when males spend time together | Daily Mail Online
In duck socialization, size does matter — Mount Holyoke News
Do Ducks Have a Penis? - Cackle Hatchery
Duck has penis removed after mating 10 times a day
Duck Penis Paradox: PLOS One's Mission to Democratize Science | The New Republic
Duck Penises, Mating Habits, and Drake Behavior. An Exchange with Patty Brennan, PhD, Professor of Biology at Mount Holyoke College — Sanctuary @ SHO
Pet duck needs penis removed after trying to mate 'between 5 and 10 times' per day: 'It was pretty horrific' | Fox News
