Common Tern vs Long-tailed Sylph

Sterna hirundo compared with Aglaiocercus kingii

Key Differences

• Common Tern is Endangered while Long-tailed Sylph is Least Concern.

Taxonomic Classification

Rank	Common Tern	Long-tailed Sylph
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Aves (Birds)	Aves (Birds)
Order	Charadriiformes (Charadriiformes)	Apodiformes (Apodiformes)
Family	Laridae	Trochilidae
Genus	Sterna	Aglaiocercus
Species	Sterna hirundo	Aglaiocercus kingii

Evolutionary Relationship

Common Tern and Long-tailed Sylph share a common ancestor at the Class level: Aves. (Birds)

Conservation Status

Common Tern

EN — Endangered

Long-tailed Sylph

LC — Least Concern

Physical Characteristics

Attribute	Common Tern	Long-tailed Sylph
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.

Long-tailed Sylph

Habitat

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

Range

Distributed across Colombia, Ecuador, Norway, and Venezuela.

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.

Long-tailed Sylph

One of the most strikingly ornamented hummingbirds, male long-tailed sylphs have iridescent green plumage and dramatically elongated, ribbon-like outer tail feathers reaching up to 22 cm — over three times the body length. Found in Andean cloud forests of Colombia and Venezuela, they inhabit humid montane forest between 1,400–2,800 meters elevation. Males perform elaborate display flights to attract females. Their extravagant tails are a classic example of sexual selection via female preference.

Shared Countries

Both species can be found in 4 countries:

🇨🇴 Colombia 🇪🇨 Ecuador 🇳🇴 Norway 🇻🇪 Venezuela