Mergus merganser
Largest sawbill. Male: white to pinkish white plumage with black back and dark green head. Female with grey body and brown head. Sharp division between brown head and whitish breast, together with contrasting white chin, distinguishes it from female Red-breasted Merganser. Both sexes with hook at tip of bill, dense crest and swollen base of bill. Wing-bars all white. Flight silhouette more diver-like than duck-like.
Male: Mostly heard when courting. A twanging, disyllabic "whip-ooooo", first syllable ascending and second whistle-like and rapidly falling. Female: A coarse "ahrrr ahrrrr", or a raspy drawn "ah-ahrrrrrr ah-ahrrrrr", slightly rising, then falling in pitch. Also various cackling sounds.
Wikipedia: map (se also Xeno-canto below)
Birdlife ecology
Sounds:Recorded by Paul Driver,http://www.xeno-canto.org ,CC license
