The male is especially handsome and, like so many "black and white" birds, has purple, green and blue colours in his feathers. He even has a hipster hairstyle!
The population of tufted ducks increased markedly over 100 years ago after the colonisation of the UK by zebra mussels. More recently numbers have been fairly stable. This graph is from the BTO/JNCC/RSPB Breeding Bird Survey.
The BTO Bird Atlas distribution maps show that tufted ducks are widespread in much of England apart from the north west and south west, with fewer in Wales and Scotland. Many of our winter tufted ducks are continental visitors. The overwintering population is over 100,000 birds with fewer than 1 in 6 staying to breed.