Phalacrocorax carbo
Easily confused with Shag when not in breeding plumage. Cormorant is larger, heavier built, has a thicker neck and less rounded profile. Head diagnostically wedge-shape, with the back of the head as the highest point. Bill never yellow (but yellow naked area at base of bill). Juveniles usually with whiter belly than Shag, and with less brown tinge. Behavioural differences from shag; often dives without jumping, more common in brackish water, often flies high, and often chooses higher ground or objects when perching. Slower wing-beats than Shag, with more separated primaries. Subspecies sinensis with larger gular poach angle (se fig.).
Mostly heard at breeding ground. Coarse, vibrating calls "hahahahaharo". Also deep, rattling and creaking sounds.
Xeno-canto: map
Birdlife ecology
Sounds:Recorded by Anon Torimi,http://www.xeno-canto.org ,CC license