Bigeye thresher vs Ring-necked Duck

Alopias pelagicus compared with Aythya collaris

Key Differences

• Bigeye thresher is Endangered while Ring-necked Duck is Least Concern.

Taxonomic Classification

Rank	Bigeye thresher	Ring-necked Duck
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Aves (Birds)
Order	Lamniformes (Mackerel Sharks)	Anseriformes (Anseriformes)
Family	Alopiidae	Anatidae
Genus	Alopias	Aythya
Species	Alopias pelagicus	Aythya collaris

Evolutionary Relationship

Bigeye thresher and Ring-necked Duck share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bigeye thresher

EN — Endangered

Ring-necked Duck

LC — Least Concern

Physical Characteristics

Attribute	Bigeye thresher	Ring-necked Duck
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Bigeye thresher

Habitat

Typically found in marine environments from coastal waters to deep ocean.

Range

Distributed across Colombia and Taiwan. Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Ring-necked Duck

Habitat

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

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Colombia, Ecuador, Venezuela).

Bigeye thresher

The Bigeye thresher (Alopias pelagicus) is a species in the genus Alopias. It is currently classified as Endangered on the IUCN Red List. Typically found in marine environments from coastal waters to deep ocean.

Ring-necked Duck

Ring-necked Duck (Aythya collaris) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.

Shared Countries

Both species can be found in 2 countries:

🇨🇴 Colombia 🇹🇼 Taiwan