blue whale vs Common Merganser

Balaenoptera musculus compared with Mergus merganser

Key Differences

• blue whale is Vulnerable while Common Merganser is Least Concern.

Taxonomic Classification

Rank	blue whale	Common Merganser
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Cetacea (Whales & Dolphins)	Anseriformes (Anseriformes)
Family	Balaenopteridae (Rorquals)	Anatidae
Genus	Balaenoptera (Rorquals)	Mergus
Species	Balaenoptera musculus	Mergus merganser

Evolutionary Relationship

blue whale and Common Merganser share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

blue whale

VU — Vulnerable

Population: ~15.0K

Trend: Increasing ↑

Common Merganser

LC — Least Concern

Physical Characteristics

Attribute	blue whale	Common Merganser
Diet	Carnivore	—
Average Lifespan	90 years	—
Average Length	30.0 m	—
Average Weight	150.0 t	—

Habitat & Geographic Range

blue whale

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (4 countries), and South America (Colombia, Ecuador). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Merganser

Habitat

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

Range

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

blue whale

The largest animal ever known to have lived on Earth, blue whales can reach 33 meters and 200 tonnes — their hearts alone weigh as much as a small car. Found in all oceans, they migrate between polar feeding grounds and tropical breeding areas. Filter feeders consuming up to 4 tonnes of krill daily. Endangered, with global populations estimated at 10,000–25,000 after near-extinction from 20th-century whaling.

Common Merganser

<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 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden