Animal genitalia: birds and fish | All you need is Biology
Patricia Brennan: 'Many scientists have studied penises, but there is an incredible gap in our understanding of vaginas' | Science & Tech | EL PAÍS English
Argentine Blue-bill, Argentine Lake Duck or Argentine Ruddy Duck
Vagina of Pekin duck opened to show cavities. (Photo: P. Brennan.) | Download Scientific Diagram
Why are duck penises corkscrew-shaped and how do they mate? | BBC Science Focus Magazine
Why are duck penises corkscrew-shaped and how do they mate? | BBC Science Focus Magazine
Sexual competition has endowed ducks with enormous organs | Science Illustrated
Argentine Blue-bill, Argentine Lake Duck or Argentine Ruddy Duck
Argentine Blue-bill, Argentine Lake Duck or Argentine Ruddy Duck