Common Seal vs Lesser Crested Tern

Phoca vitulina compared with Thalasseus bengalensis

Key Differences

• Common Seal is Near Threatened while Lesser Crested Tern is Not Evaluated.

Taxonomic Classification

Rank	Common Seal	Lesser Crested 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	Phoca (Harbor Seals)	Thalasseus
Species	Phoca vitulina	Thalasseus bengalensis

Evolutionary Relationship

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

Conservation Status

Common Seal

NT — Near Threatened

Population: ~500.0K

Trend: Stable →

Lesser Crested Tern

NE — Not Evaluated

Physical Characteristics

Attribute	Common Seal	Lesser Crested Tern
Diet	Carnivore	—
Average Lifespan	30 years	—
Average Length	1.7 m	—
Average Weight	80.0 kg	—

Habitat & Geographic Range

Common Seal

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (7 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Lesser Crested Tern

Habitat

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

Range

Distributed across Norway and Sweden.

Common Seal

The most widely distributed pinniped, harbor seals inhabit temperate and subarctic coastal waters of both the North Atlantic and North Pacific. Adults reach up to 130 kg and spend roughly equal time at sea hunting fish, squid, and crustaceans and hauling out on beaches or rocks to rest. Their large, expressive eyes are adapted for underwater vision in low light. Harbor seals are a critical food source for orcas, sharks, and polar bears.

Shared Countries

Both species can be found in 2 countries:

🇳🇴 Norway 🇸🇪 Sweden