Atlantic Gray Seal vs Common Tern

Halichoerus grypus compared with Sterna hirundo

Key Differences

• Atlantic Gray Seal is Vulnerable while Common Tern is Endangered.

Taxonomic Classification

Rank	Atlantic Gray Seal	Common Tern
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Mammalia (Mammals)	Aves (Birds)
Order	Pinnipedia (Seals & Sea Lions)	Charadriiformes (Charadriiformes)
Family	Phocidae (True Seals)	Laridae
Genus	Halichoerus	Sterna
Species	Halichoerus grypus	Sterna hirundo

Evolutionary Relationship

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

Conservation Status

Atlantic Gray Seal

VU — Vulnerable

Common Tern

EN — Endangered

Physical Characteristics

Attribute	Atlantic Gray Seal	Common Tern
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 Tern

Habitat

Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 9 distinct biome types spanning the Neotropic and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Europe (7 countries), North America (United States), and South America (Colombia, Ecuador, Venezuela). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

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 Tern

Common Tern (Sterna hirundo) is classified as Endangered (EN) on the IUCN Red List. At high risk of extinction in the wild, with significant population decline and ongoing threats to survival.

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden