Duck in a Ditch.

Jesus Ditch, borders the grounds of Jesus College and is an off-shoot of Medieval King's Ditch, once part of the town's open sewer. It is now a haven for wildlife and I managed to get a shot of this duck emerging from it's hiding place in the reeds. It was quite distinctive with a bright red bill, but I'm not sure what type of duck it is. Hopefully a blipfriend will enlighten me.