vs Cock-tailed Tyrant

Cocconeis disculus compared with Alectrurus tricolor

Key Differences

is Not Evaluated while Cock-tailed Tyrant is Vulnerable.

Taxonomic Classification

Rank		Cock-tailed Tyrant
Kingdom	Chromista (Chromista)	Animalia (Animals)
Phylum	Ochrophyta (Ochrophyta)	Chordata (Chordates)
Class	Bacillariophyceae (Bacillariophyceae)	Aves (Birds)
Order	Achnanthales (Achnanthales)	Passeriformes (Songbirds)
Family	Cocconeidaceae	Tyrannidae
Genus	Cocconeis	Alectrurus
Species	Cocconeis disculus	Alectrurus tricolor

Conservation Status

NE — Not Evaluated

Cock-tailed Tyrant

VU — Vulnerable

Physical Characteristics

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

Habitat & Geographic Range

Habitat

Native to Europe and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, and Sweden.

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.

Cocconeis disculus is a freshwater and brackish-water diatom in the family Cocconeidaceae, belonging to the class Bacillariophyceae—the diatoms, a group of unicellular photosynthetic algae encased in ornate silica cell walls called frustules. Like all members of the genus Cocconeis, C. disculus is an adnate, epiphytic species, meaning it lives attached to substrates—typically the surfaces of aquatic macrophytes, filamentous algae, and sediment particles—rather than living freely in the water column. The frustule of Cocconeis species is distinctive in its bilateral symmetry and the characteristic difference between its two valves: the rapheless valve (RV) lacks the raphe slit present on the raphe valve (RV), a feature used in species identification. Cocconeis disculus has been documented from freshwater bodies across South America and various parts of the Northern Hemisphere, with distribution reflecting its tolerance of a range of water temperatures and nutrient conditions. Diatoms like C. disculus are foundational components of aquatic food webs, fixing carbon through photosynthesis and providing a nutritious food source for grazing invertebrates, protists, and larval fish. The species also contributes to the biosilica cycle through the production and dissolution of its silica frustule. As a benthic, substrate-attached organism, Cocconeis disculus serves as a sensitive bioindicator of water quality conditions in freshwater monitoring programs. Its conservation status is not formally evaluated.

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.