ID Uncle Donald please- a large Mallard (?) male

Can anyone identify this bird please? It's about twice the size of regular Mallard male, and has taken the role of protecting the chicks all summer.

Usually male Mallards abandon their brood straight away but this one has stayed and looked after the females and the chicks.

It's mostly coloured like a regular Mallard male, but with some spots on the sides and back. There are a lot of wild and cultivated species around, so a cross breed seems likely.

Thanks!

 

He might be a mule duck or a mulard - a cross between a Muscovy duck and a Mallard. It seems that this does happen in the wild but the offspring are infertile. Which might account for his looking after the youngsters of other ducks.

 

There has been lots of breeding in ducks and mallards can now be found that look more goose like in proportions. They seem to hybridise quite readily as well, a mallard got in with some pekins and produced something similar at a farm I know. There is also a species called the rouen duck which just looks like a giant mallard. I don't think anyone would know for certain without dna testing.

 

Thank you @Tidemark and @Thevictorian !

I have done quite a bit of googling and some Rouen duck somewhere in the family tree looks likely- the body shape is indeed quite heavy towards the tail and the colouring and size match.

The protective behaviour with the ducklings has been interesting to watch over the summer