Willis was in Perth, Australia in December 2008 where he documented the copulation of a pair of Hardhead (Aythya australis). Like all ducks, these Hardheads copulated on water. The male mounted the female for a few seconds, biting her on the nape in the process. His weight totally submerged her into the water where copulation must have taken place. This is possible because, like all ducks and unlike most other birds, the male Hardhead has a penis that allows the transference of sperms underwater.
Moments later, the pair started thrashing around the water. Well, the male usually spread his neck and makes a loud call immediately after copulation. He may even spreads his wings. The female then baths and preens for some time.
John Vickerman commented in the Nature Pixels forum: “Great sequence of the mating game here! Most wildfowl, mate in the water and it is quite normal for the female to be completely submerged for a time. The male holding onto the nape of the female is essential for the stability of the pair in the water, otherwise he would fall off, and that is not a good way to achieve the intended result! However, there have been some recorded instances whereby a female attracts the attention of a whole army of suitors with the upshot being that the female becomes the unwitting centre of a mad mating frenzy, a kind of gang rape, and very occasionally the female is actually drowned in the process. Very rare but it does happen.
“The thrashing around in the water you see here is, as you quite rightly surmise, a final culmination of the act and is a very visual and active consolidation of the pair bond. It is, at the same time, a visual warning to other birds, especially males, that ‘we are an item – keep your distance’. The more violent the thrashing about in the water, the more effective this action is in discouraging other males to come along and try their luck to have their wicked way with that particular female, and likewise, a warning to other females that ‘my mate is strong, don’t anyone come along and distract him from me’. It’s all part of the show!”
All images by willis.
This post is a cooperative effort between NaturePixels.org and BESG to bring the study of bird behaviour through photography to a wider audience.