Brook Floater vs Common Tern

Alasmidonta varicosa compared with Sterna hirundo

Key Differences

• Brook Floater is Vulnerable while Common Tern is Endangered.

Taxonomic Classification

Rank	Brook Floater	Common Tern
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Mollusca (Mollusks)	Chordata (Chordates)
Class	Bivalvia (Bivalvia)	Aves (Birds)
Order	Unionida (Unionida)	Charadriiformes (Charadriiformes)
Family	Unionidae	Laridae
Genus	Alasmidonta	Sterna
Species	Alasmidonta varicosa	Sterna hirundo

Evolutionary Relationship

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

Conservation Status

Brook Floater

VU — Vulnerable

Common Tern

EN — Endangered

Physical Characteristics

Attribute	Brook Floater	Common Tern
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Brook Floater

Habitat

Native to North America, inhabiting ecosystems characteristic of the region.

Range

Found in United States. 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.

Brook Floater

The Brook Floater (Alasmidonta varicosa) is a species in the genus Alasmidonta. It is currently classified as Vulnerable on the IUCN Red List. Native to North America, inhabiting ecosystems characteristic of the region.

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 1 countries:

🇺🇸 United States