Bigeye thresher vs Choco Vireo

Alopias pelagicus compared with Vireo masteri

Taxonomic Classification

Rank	Bigeye thresher	Choco Vireo
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Aves (Birds)
Order	Lamniformes (Mackerel Sharks)	Passeriformes (Songbirds)
Family	Alopiidae	Vireonidae
Genus	Alopias	Vireo
Species	Alopias pelagicus	Vireo masteri

Evolutionary Relationship

Bigeye thresher and Choco Vireo share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bigeye thresher

EN — Endangered

Choco Vireo

EN — Endangered

Physical Characteristics

Attribute	Bigeye thresher	Choco Vireo
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.

Choco Vireo

Habitat

Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 4 distinct biome types within the Neotropic biogeographic realm.

Range

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

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.

Choco Vireo

The Choco Vireo (Vireo masteri) is a small, poorly known passerine in the family Vireonidae, with a highly restricted range in the western Andes foothills on the Pacific slope of Colombia and possibly adjacent Ecuador. It was described scientifically only in 1997, reflecting the challenges of survey work in the remote, wet, and botanically complex terrain of the Colombian Chocó. The Choco Vireo is a small greenish-yellow vireo with a distinctive facial pattern including a pale supercilium and dark eye-stripe. Like other vireos, it forages methodically through mid-canopy and sub-canopy foliage, gleaning caterpillars, beetles, and other invertebrates from leaves. Its song is a series of high, slurred phrases repeated with characteristic vireonid persistence. The species appears restricted to humid montane and foothill forest at elevations roughly between 800 and 1,800 metres — a zone severely impacted by the expansion of coca cultivation, illegal logging, and cattle ranching in the Colombian Pacific region. The IUCN classifies the Choco Vireo as Endangered given its extremely small and severely fragmented range and continued loss of suitable forest habitat. Very little is known about its population size, ecology, or breeding biology, making targeted survey and monitoring urgently needed.

Shared Countries

Both species can be found in 1 countries:

🇨🇴 Colombia