カワアイサ vs コウライアイサ

Mergus merganser compared with Mergus squamatus

Key Differences

• カワアイサ is Least Concern while コウライアイサ is Endangered.

Taxonomic Classification

Rank	カワアイサ	コウライアイサ
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum same	Chordata (脊索動物)	Chordata (脊索動物)
Class same	Aves (鳥類)	Aves (鳥類)
Order same	Anseriformes (カモ目)	Anseriformes (カモ目)
Family same	Anatidae	Anatidae
Genus same	Mergus	Mergus
Species	Mergus merganser	Mergus squamatus

Evolutionary Relationship

カワアイサ and コウライアイサ share a common ancestor at the Genus level: Mergus.

Conservation Status

カワアイサ

LC — Least Concern

コウライアイサ

EN — Endangered

Physical Characteristics

Attribute	カワアイサ	コウライアイサ
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

カワアイサ

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Found across Europe (5 countries) and North America (United States).

コウライアイサ

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Distributed across Norway and Taiwan. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

カワアイサ

<em>Mergus merganser</em>, the common merganser or goosander, is a large diving duck in the family Anatidae, broadly distributed across Europe and North America. It is classified as Least Concern on the IUCN Red List. This species is capable of aerial, terrestrial, and aquatic locomotion, but is most specialized for underwater pursuit of prey. The common merganser is typically piscivorous, diving in clear, fast-flowing rivers and lakes to catch fish using its serrated bill, which provides a firm grip on slippery prey. Males display striking breeding plumage with a dark green head, white body, and red bill, while females are grey with a rusty-brown head and crested nape. The species nests in tree cavities, cliff ledges, and artificial nest boxes near freshwater habitats. It requires clean, well-oxygenated rivers and lakes for foraging, making it sensitive to water quality degradation and overfishing of prey species. Common mergansers are migratory in northern parts of their range, moving to coastal and ice-free inland waters during winter months.

Shared Countries

Both species can be found in 1 countries:

🇳🇴 Norway