Common Merganser

Elongated duck with a flesh-colored beak.

Scientific name	Mergus merganser
English name	Common Merganser
Japanese name	Kawaaisa
Classification	Aves
Classification details	Anseriformes Anatidae
Full length	60-70cm
Distribution	Breeds in Eurasia and North America, and comes to Japan in winter.

Characteristics

A duck with an elongated silhouette. Both males and females are pure white from the neck to the chest. Males have black to dark green heads. Females are brown. The beak is a reddish flesh color with a hook-like tip.

Distinguishing between kawagaisa and sea merga

Although the two species are very similar, the division between the head and neck of the kawagaisa is more clearly visible. The similar sea mermaid has a brown color on the neck, so it can be identified here. The color of the beak is also reddish in the mermaid. In addition, the crest feathers on the head are not as well developed as the sea merfish.

Ecology

In winter, they fly to lakes, rivers, and coastal areas to overwinter. Moves in small flocks of several birds. Dive into the water and catch fish.

Habitat

Lake Suwa Kamaguchi Water Gate

I photographed an individual swimming toward the Kamaguchi water gate. The male proceeded by repeatedly diving and surfacing. The group was smaller than that of the common merganser, and it looked whiter from the neck down. I was able to see an individual relaxing on the concrete under the floodgate.