On Thu, 25 Jan 1996, Dennis Paulson wrote:
> The Ruddy Duck's penis can be almost as long as the bird. I've never seen
> Ruddies copulate, but I've been watching. I have a feeling I posted this
> some time ago, but it's a little-known fact that should be shared.

Somewhere I read that Ruddy Ducks introduced somewhere in Spain (?)
are threatening the status of a native population of another oxyurine
duck, because Ruddy males are mating with the Spanish oxyurine females
quite frequently (more so than the natives, I think). Whether this is
attributable to females choosing the Ruddies because of their stunning
good looks (or other attributes), or the Ruddies being more agressive
than the native males I don't recall.

Those who share Dennis's interest in this topic would enjoy "Sexual
selection and animal genitalia" by WG Eberhard (1985; Harvard U Press).
Covers a wide range of animals, from bugs to mammals (don't miss the
part on ruminant artiodactyls).

David Wright
dwright at u.washington.edu