Bigeye thresher vs Cinnamon-bellied Ground-Tyrant

Alopias pelagicus compared with Muscisaxicola capistratus

Key Differences

• Bigeye thresher is Endangered while Cinnamon-bellied Ground-Tyrant is Least Concern.

Taxonomic Classification

Rank	Bigeye thresher	Cinnamon-bellied Ground-Tyrant
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	Tyrannidae
Genus	Alopias	Muscisaxicola
Species	Alopias pelagicus	Muscisaxicola capistratus

Evolutionary Relationship

Bigeye thresher and Cinnamon-bellied Ground-Tyrant share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bigeye thresher

EN — Endangered

Cinnamon-bellied Ground-Tyrant

LC — Least Concern

Physical Characteristics

Attribute	Bigeye thresher	Cinnamon-bellied Ground-Tyrant
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.

Cinnamon-bellied Ground-Tyrant

Habitat

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

Range

Found in Norway.

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.

Cinnamon-bellied Ground-Tyrant

The cinnamon-bellied ground tyrant (Muscisaxicola capistratus) is a small flycatcher in the family Tyrannidae, found in the arid steppe, puna grasslands, and rocky slopes of western and central Argentina and Bolivia. It inhabits open, barren, and semi-arid environments at elevations from approximately 2,000 to 4,500 meters in the eastern Andes foothills and Patagonian steppe, foraging on the ground for insects and small invertebrates. The plumage is brown above with a distinctive rufous-cinnamon belly that contrasts with paler underparts, giving the species its common name. Like other ground tyrants in the genus Muscisaxicola, it runs and pauses across bare or sparsely vegetated ground rather than perching on vegetation. The species is classified as Least Concern by the IUCN, with a restricted but apparently stable South American range. Ground tyrants as a group represent a highly successful Andean radiation into open, high-altitude habitats. This species is entirely absent from Europe; any database record associating it with Norway is a data artifact. Threats include overgrazing of native steppe vegetation by livestock, which can degrade foraging habitat, and climate-driven changes in Andean precipitation and vegetation cover.