Red-breasted Merganser

How to recognise it

• Breeding male: black head with a greenish gloss, long crest, white collar and rusty breast
• Female has a reddish-brown head and upper neck but no white chin patch
• Long, slim, straight red bill with serrated edges, red feet and a ragged crest
• Black bars on white wing patch, eclipse male resembles female but with large white wing patch

Call and song

It is mostly silent. The female's rolling "prrak prrak prrak" is often heard, and in flight she gives a harsh "gruk". The male's display call is rarely heard and very faint, like a rhythmic hiccup and a sneeze with a pause between.

Where and when

It is a partial migrant that breeds in Sweden. It is reported all year and from all 21 counties. The population was estimated at 21 000 pairs in 2018. Autumn migration starts in September, and some return as early as February. In June males leave to moult in small groups on the coast. Some winter near the breeding areas, for example on the west coast.

Food and behaviour

It feeds mostly on small schooling fish, as well as plant material and aquatic invertebrates. Several mergansers often hunt together and catch their prey by diving. On migration and in winter quarters it often gathers in flocks of up to a hundred birds or more. In display the males stretch, bend and pull in their necks, often several at once.