A diving duck with a long, thin bill and shaggy crest. It catches and eats fish.
Breeding males have a shaggy dark green head, red bill, and rusty chest. Females and nonbreeding males have brownish heads and gray-brown bodies.
A red-breasted merganser catching a slender fish may take time to swallow it at the surface. On Norway’s west coast, birds surfaced holding pipefish with narrow tails protruding from their bills. In one example, handling after capture took longer than the underwater pursuit.
The observation took place on the afternoon of 14 January 2007 at Kilstraumen, a shallow sound northwest of Bergen. Two adult males were feeding in fairly strong currents. At least eight successful catches were seen during a ten-minute watch. The birds repeatedly returned to the surface holding slender fish.
Dives and pursuits lasted less than 20 seconds, while handling and swallowing took as long as 25 seconds in one instance. A short underwater chase could thus be followed by a longer task at the surface, with a fish’s tail still visible beyond the bill.
An extinction-risk assessment has not been added yet.
Reducing approaches that interrupt rest and preening is a conservation concern along coasts where red-breasted mergansers raise ducklings. Observations at three Danish sites in 1991–1992 linked encounters with fast-moving fishing boats, motorboats and windsurfers to changes in brood behaviour. Disturbed ducklings commonly gathered around the female and swam away. The paper calls for the needs of summer-breeding birds to be considered when managing coastal recreation.