Original note
What the duck?
Male ducks have penises—unusual among birds, because most male birds don’t.
A duck’s penis is retractable, often corkscrew-shaped, and can be surprisingly long relative to its body. Female ducks have correspondingly complex, spiral-shaped reproductive tracts, partly understood as an evolutionary response to forced mating. It’s one of the stranger reproductive arms races in nature.
A duck’s penis is retractable, often corkscrew-shaped, and can be surprisingly long relative to its body. Female ducks have correspondingly complex, spiral-shaped reproductive tracts, partly understood as an evolutionary response to forced mating. It’s one of the stranger reproductive arms races in nature.
