Common Merganser

The common merganser, or goosander, is a large duck of rivers and lakes in forested areas of Europe, Asia and North America, 58 to 72cm long with a wingspan of 78 to 97cm. Breeding males are easily recognised, with a white body with a salmon-pink tinge, a black head with an iridescent green sheen and largely white inner wings. Females and eclipse males are largely grey with a reddish-brown head and white chin (Wikipedia, general species account).

These fish-eating ducks have serrated bill edges to grip prey, so are known as sawbills. They nest in holes in trees, so need mature forest for breeding, and the young are sexually mature at two years. The sources opened give nothing specific to Bhutan.