Scaly-sided Merganser Mergus squamatus

The Scaly-sided or Chinese Merganser breeds in the Russian Far East, northern China and North Korea and spends winter in southern China, South Korea, Taiwan and Japan. It is highly endangered by deforestation, pollution, hunting, being out-competed by its relative the Goosander and predated by introduced species such as mink.

Above left is a pair (male and female). Above right is a male in transition to eclipse plumage. The latter has a black back rather than the female's grey but his head has already turned to the brown of the female rather than his breeding plumage of iridescent green-black.

The scientific name "squamatus" refers to the pattern of reptilian scales on its sides. (Above centre with Japanese Black-tailed Gull.)

Like other mergansers, it mainly dives underwater to feed.