Common Tern vs small tortoiseshell

Sterna hirundo compared with Aglais urticae

Key Differences

• Common Tern is Endangered while small tortoiseshell is Near Threatened.

Taxonomic Classification

Rank	Common Tern	small tortoiseshell
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Arthropoda (Arthropods)
Class	Aves (Birds)	Insecta (Insects)
Order	Charadriiformes (Charadriiformes)	Lepidoptera (Butterflies & Moths)
Family	Laridae	Nymphalidae (Brush-footed Butterflies)
Genus	Sterna	Aglais
Species	Sterna hirundo	Aglais urticae

Evolutionary Relationship

Common Tern and small tortoiseshell share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Common Tern

EN — Endangered

small tortoiseshell

NT — Near Threatened

Physical Characteristics

Attribute	Common Tern	small tortoiseshell
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic 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.

small tortoiseshell

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (41 countries). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

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.

small tortoiseshell

small tortoiseshell (Aglais urticae) is classified as Near Threatened (NT) on the IUCN Red List. Close to qualifying as threatened, with populations that may become vulnerable without conservation action.

Shared Countries

Both species can be found in 7 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇱🇺 Luxembourg 🇳🇴 Norway 🇵🇹 Portugal 🇷🇺 Russia 🇸🇪 Sweden