Cock-tailed Tyrant vs Shelled Slug

Alectrurus tricolor compared with Testacella haliotidea

Key Differences

• Cock-tailed Tyrant is Vulnerable while Shelled Slug is Data Deficient.

Taxonomic Classification

Rank	Cock-tailed Tyrant	Shelled Slug
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Chordata (Chordates)	Mollusca (Mollusks)
Class	Aves (Birds)	Gastropoda (Gastropoda)
Order	Passeriformes (Songbirds)	Stylommatophora (Stylommatophora)
Family	Tyrannidae	Testacellidae
Genus	Alectrurus	Testacella
Species	Alectrurus tricolor	Testacella haliotidea

Evolutionary Relationship

Cock-tailed Tyrant and Shelled Slug share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cock-tailed Tyrant

VU — Vulnerable

Shelled Slug

DD — Data Deficient

Physical Characteristics

Attribute	Cock-tailed Tyrant	Shelled Slug
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cock-tailed Tyrant

Habitat

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

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Shelled Slug

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Widely distributed across Europe (9 countries), North America (United States), and Oceania and the Pacific (New Zealand).

Cock-tailed Tyrant

The cock-tailed tyrant (Alectrurus tricolor) is a striking and unusual flycatcher in the family Tyrannidae, named for the remarkable elongated, spatula-shaped outer tail feathers of the male, which can exceed the body length and are displayed during aerial courtship flights over open grasslands. The species inhabits wet and seasonally flooded grasslands, cerrado savanna, and campos in the interior of South America, including central Brazil, eastern Bolivia, Paraguay, and northeastern Argentina — not Norway, as erroneous database entries suggest. Males combine conspicuous black, white, and rufous plumage with their extraordinary tail streamers in an elaborate display to attract females on leks; females are cryptically streaked brown. The cock-tailed tyrant is a ground- and low-vegetation forager, preying on insects and other small invertebrates gleaned from grass stems and caught in aerial sallies. The species is classified as Vulnerable by the IUCN due to extensive and continuing conversion and degradation of its native Neotropical grassland habitat through intensive soy and sugarcane agriculture, cattle ranching, fire management changes, and drainage of seasonally flooded grasslands. Populations have declined significantly across much of its range, particularly in Brazil and Paraguay. The species is a flagship for threatened grassland conservation in South America, where relatively little protection has historically been directed at open-country habitats compared to forest ecosystems.