Common Merganser

How to recognise it

• Long, slim red bill with a small downcurved black hook at the tip
• Breeding male has a dark green head, black back and almost white wings
• Female has a red-brown head sharply divided from the pale neck, white chin, long nape feathers
• In flight it looks like a diver or grebe, with a long outstretched neck

Call and song

The usual call is a low, hoarse croak. The displaying male gives a muted, ringing "krroo-krråå", and the female gives a hard "pra, pra-pra" during courtship. In flight it is louder, with a grinding "prrah, prrah, prrah" and a faster "tjackerack-ack-ack".

Where and when

The Common Merganser occurs across Sweden and is most numerous in the eastern archipelago. It is a partial migrant that breeds here. It often winters on the east coast south of Stockholm unless the Baltic freezes completely. Many Swedish birds winter on the west coast, in Denmark, Germany, Poland and the Netherlands. It is reported most in November to March, and from all 21 counties.

Food and behaviour

It feeds mainly on smaller fish, and besides fish it takes molluscs, crustaceans, worms, insect larvae and amphibians. In autumn, flocks fish together in a line parallel to the shore, driving small fish towards land by diving and splashing their wings. It often sits on a rock in the water with half-open wings in the sun, like cormorants. The nest is often in a tree hole or nest box.