Excuse the title, but I'm confused. This picture bears many major similarities to a Ruddy duck, but it also displays some jarring not-quite-rightnesses: the beak shape doesn't seem entirely correct, the head not chunky enough and the body plumage doesn't match. But there surely aren't many ducks with a blue bill and black and white head? Perhaps it's a non-UK exotic, since I saw it at Pensthorpe, which might mean all bets are off! Is it a cross-breed, e.g. a Ruddy Mallard? Is that even possible? Answers on a postcard please (or in the comments below).

I figure that the one at the back is a Merganser of some sort.

Answer: no – it's not a Ruddy duck. It is in fact a Puna Teal, native to South America. Thanks to Blackbird for enlightening us all in the comments!