Dysithamnus occidentalis
The Bicolored Antvireo (Dysithamnus occidentalis) is a small, enigmatic passerine belonging to the antbird family (Thamnophilidae), known for its subtle yet striking plumage. Measuring approximately 12-13 cm (4.7-5.1 in) in length and weighing around 18-22 grams, this species exhibits moderate sexual dimorphism. Males typically sport a slate-gray to blackish head, back, and wings, contrasting sharply with a bright rufous belly and flanks, hence its common name. Females are duller, often with ...
This species primarily inhabits the dense, humid understory and mid-story of montane cloud forests and humid evergreen forests, typically at elevations ranging from 1,200 to 2,200 meters (3,900-7,200 feet) above sea level. It prefers areas with a thick tangle of vegetation and mossy branches.
The diet of the Bicolored Antvireo consists primarily of insects and other small arthropods, which it obtains by gleaning meticulously from foliage and mossy branches.
The Bicolored Antvireo is a diurnal and rather inconspicuous bird, spending its day actively foraging in the lower to mid-canopy strata of its dense forest habitat. It often participates in mixed-species foraging flocks, moving slowly and deliberately, gleaning insects and other arthropods from l...
The Bicolored Antvireo is a resident species with a highly fragmented distribution along the western slopes of the Andes, occurring in three disjunct populations. The northernmost population is found in the Western and Central Andes of Colombia, extending narrowly into the northernmost part of Ec...
Vulnerable
- The Bicolored Antvireo is a "professional" member of mixed-species foraging flocks, often relying on the safety and increased foraging efficiency these groups provide. - Despite its striking bicolored plumage, this species is notoriously difficult to observe due to its preference for dense unde...