The Bufflehead is a North American sea duck. It breeds mainly inland on wooded lakes in Canada/Alaska.
The Bufflehead drake in breeding plumage has iridescent purple and green highlights on his head - a real petrolhead.
The Bufflehead female is mainly grey with a brown head and white cheek-spot.
Bufflehead pair, duck and drake (he's in transition to eclipse plumage in centre picture above).
The Bufflehead is a very small duck (cf. Black-headed Gull).
He's a Petrol-head.
She also has a white belly.