カワアイサ vs ウミアイサ

Mergus merganser compared with Mergus serrator

Taxonomic Classification

Rank	カワアイサ	ウミアイサ
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 serrator

Evolutionary Relationship

カワアイサ and ウミアイサ share a common ancestor at the Genus level: Mergus.

Conservation Status

カワアイサ

LC — Least Concern

ウミアイサ

LC — Least Concern

Physical Characteristics

Attribute	カワアイサ	ウミアイサ
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).

ウミアイサ

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Colombia).

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.

ウミアイサ

ウミアイサ（Mergus serrator）はIUCNレッドリストで軽度懸念（LC）に分類されている。分布域全体で広く豊富に生息し、個体群は安定しており、直接的な保全上の懸念はない。

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States