Atlantic Gray Seal vs Common Loon

Halichoerus grypus compared with Gavia immer

Key Differences

• Atlantic Gray Seal is Vulnerable while Common Loon is Not Evaluated.

Taxonomic Classification

Rank	Atlantic Gray Seal	Common Loon
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Pinnipedia (Seals & Sea Lions)	Gaviiformes (Gaviiformes)
Family	Phocidae (True Seals)	Gaviidae
Genus	Halichoerus	Gavia
Species	Halichoerus grypus	Gavia immer

Evolutionary Relationship

Atlantic Gray Seal and Common Loon share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Atlantic Gray Seal

VU — Vulnerable

Common Loon

NE — Not Evaluated

Physical Characteristics

Attribute	Atlantic Gray Seal	Common Loon
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Atlantic Gray Seal

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

Distributed across Belgium, Denmark, Norway, Portugal, and Sweden. 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.

Atlantic Gray Seal

The Atlantic Gray Seal (Halichoerus grypus) is a species in the genus Halichoerus. It is currently classified as Vulnerable on the IUCN Red List. Typically found in diverse terrestrial and aquatic ecosystems.

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 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden