blue whale vs Common Loon

Balaenoptera musculus compared with Gavia immer

Key Differences

• blue whale is Vulnerable while Common Loon is Not Evaluated.

Taxonomic Classification

Rank	blue whale	Common Loon
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Cetacea (Whales & Dolphins)	Gaviiformes (Gaviiformes)
Family	Balaenopteridae (Rorquals)	Gaviidae
Genus	Balaenoptera (Rorquals)	Gavia
Species	Balaenoptera musculus	Gavia immer

Evolutionary Relationship

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

Conservation Status

blue whale

VU — Vulnerable

Population: ~15.0K

Trend: Increasing ↑

Common Loon

NE — Not Evaluated

Physical Characteristics

Attribute	blue whale	Common Loon
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 Loon

Habitat

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

Range

Distributed across Belgium, Denmark, Norway, Sweden, and 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 Loon

<em>Gavia immer</em>, the common loon or great northern diver, is a large aquatic bird in the family Gaviidae, known for its haunting, yodeling calls across northern lakes. It is found in Belgium, Denmark, Norway, Sweden, and the United States, breeding on freshwater lakes in boreal and subarctic regions and wintering along marine coastlines. The common loon is adept in aerial, terrestrial, and aquatic environments, though it is most highly specialized for diving, using its strong feet positioned far back on its body to pursue fish underwater. It typically feeds on fish, supplemented by crustaceans and aquatic invertebrates. Its striking summer plumage features a black-and-white checkered back and a deep black head with a characteristic white necklace pattern. The species has not been evaluated for IUCN conservation status. Common loons require clear, fish-rich lakes for successful breeding and are sensitive to water quality degradation and human disturbance at nesting sites. Their distinctive calls are emblematic of wilderness in North America and Scandinavia.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden