Common Eider vs Long-tailed Sylph

Somateria mollissima compared with Aglaiocercus kingii

Key Differences

• Common Eider is Near Threatened while Long-tailed Sylph is Least Concern.

Taxonomic Classification

Rank	Common Eider	Long-tailed Sylph
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class same	Aves (Birds)	Aves (Birds)
Order	Anseriformes (Anseriformes)	Apodiformes (Apodiformes)
Family	Anatidae	Trochilidae
Genus	Somateria	Aglaiocercus
Species	Somateria mollissima	Aglaiocercus kingii

Evolutionary Relationship

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

Conservation Status

Common Eider

NT — Near Threatened

Long-tailed Sylph

LC — Least Concern

Physical Characteristics

Attribute	Common Eider	Long-tailed Sylph
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Eider

Habitat

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

Range

Found across Europe (5 countries) and North America (United States). Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

Long-tailed Sylph

Habitat

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

Range

Distributed across Colombia, Ecuador, Norway, and Venezuela.

Common Eider

Common Eider (Somateria mollissima) 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.

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 1 countries:

🇳🇴 Norway