Mallard

We popped into the Arundel Wildfowl and Wetland place en route to Chichester today and were dismayed to discover that our Family membership didn't allow us all in as it only covers two adults and two children 16 years old or under. So we had to fork out £9.95 for our eldest, which is the rather daunting student rate. As Matty pointed out: it's really somewhere only the affluent middle-classes would go. Fair enough. It's also a charity doing good work, my wife chipped in. So we paid up, plus some for feed, and had a lovely couple of hours pootling around the reserve.
There were of course some wonderful rarities, but how could one not start with the ubiquitous mallard: Anas platyrhynchos. The name 'mallard' is thought to come from various Old languages, meaning 'drake duck' but it's not very clear. The binomial species name means 'broad/flat nosed'.

And it really is found all over the place, barring Antarctica. It is in the Anseriformes Order and the Anatidae family. This latter contains most of our ducks, geese and swans - although the magpie goose, which turns up in huge numbers at Kakadu National Park in Australia's Northern Territory, belongs to a different family.
Numbers in the UK are swelled by a few winter migrants from Scandinavia and central Europe, but less so than in the past. They swell numbers by around 3%.
Mallard males have a bit of a bad reputation on account of their tendency to commit gang rape. Groups of unpaired males will sometimes pick out an unpaired female, or even another male, chase it until weakened and then copulate with it in turn. There is even a report of homosexual necrophilia, the submission of which won the scientist an Ig Noble prize.