The smew (Mergellus albellus) is a species of duck and is the only living member of the genus Mergellus. Mergellus is a diminutive of Mergus and albellus is from Latin albus "white". This genus is closely related to Mergus and is sometimes included in it, though it might be closer to the goldeneyes (Bucephala). The smew has hybridized with the common goldeneye (B. clangula). They forage by diving from the surface and also swimming underwater when pursuing prey. They forage in groups periodically submerging their heads underwater and then without a splash, the entire flock vanishes beneath the water. The Smew is a compact diving duck with a delicate bill. The male is white with a black mask and a black back, the female is grey with a reddish-brown head and white cheek. In flight, it shows black and white wings. It's a winter visitor in small numbers from Scandinavia and Russia. Smews spend a lot of time under the water hunting for food - mostly aquatic insects in summer and small fish in winter. The natural predators include the American Mink, the Long-legged Buzzard, the Rough-legged Buzzard, the Peregrine Falcon, the Merlin and the Hen Harrier. They forage by diving from the surface and also swimming underwater when pursuing prey. They are vocal birds and give a sharp “krrr” note. They forage in groups periodically submerging their heads underwater and then without a splash, the entire flock vanishes beneath the water. Here is a link so you can listen to this bird too.