Red-breasted Merganser

The Red-breasted Merganser is a slim fish-eating duck with a long, narrow red bill and a conspicuously shaggy crest. Breeding males show a dark green head, white neck collar, rusty spotted breast and grey flanks. Females are grey-bodied with warm reddish-brown heads, closely resembling female Common Mergansers but appearing slimmer and showing less sharply divided head and neck colours (Wikipedia, general species account).

This merganser breeds around northern lakes, rivers and sheltered coasts, then winters mainly on estuaries and marine bays. It dives after small fish and aquatic invertebrates and may form coordinated feeding lines that drive prey together. The female nests on the ground under vegetation or among rocks rather than normally using tree cavities (Wikipedia, general species account). The Korean catalogue records the species in South Korea.