With a bit of research, I managed to find out that this is a Bali duck. It is a little odd to see this duck, with a fluffy crest on the back of his head, trying to fit in with the other ducks. I haven't seen him around today, he might have gone back home after a short visit with his cousins in Lester's pond.
The fluff ontop of its head caught our eye. Other than being white, he's also a little larger than the other ones he's been hanging around with, back and forth across the ponds.