Rusty-winged Antwren

The Rusty-winged Antwren, scientifically known as Herpsilochmus frater, is a diminutive bird, part of the Thamnophilidae family, often referred to as the "typical antbirds." This species exhibits a length ranging from 10 to 12.5 cm and a weight approximately between 10 to 12.5 g.

Identification Tips

Males of the nominate subspecies, H. f. frater, are characterized by a black crown and nape, a prominent white supercilium, and a black stripe through the eye. Their upperparts are ashy gray with black spots and streaks, and their wings are adorned with dark cinnamon red outer webs. Females, on the other hand, boast a rich chestnut-rufous crown and a buffy chestnut supercilium, with olive-gray upperparts and more pronounced white on the tail. Both sexes share a dark gray to brownish iris, a black maxilla, and a light gray mandible with a darker tip.

Habitat

The Rusty-winged Antwren is found in the interior and edges of lowland and foothill evergreen forests, including terra firme and gallery forests. It prefers dense vine tangles and is typically observed from the forest's mid-storey to its subcanopy.

Distribution

This species has a disjunct distribution across South America, with subspecies H. f. exiguus located in Panama and northwestern Colombia, and the nominate subspecies H. f. frater found from Colombia's Eastern Andes to northern Bolivia, and eastward through Venezuela, Guyana, Suriname, and Amazonian Brazil.

Behaviour

The Rusty-winged Antwren is considered a year-round resident within its range. It forages actively and methodically, often joining mixed-species feeding flocks and typically feeding between 8 and 30 meters above ground.

Song & Calls

The song of the Rusty-winged Antwren is a unique stuttered series of notes, starting with an accelerating sequence and shifting to a raspy rattle. Its calls include a descending rattled series and a short scolding note that varies tonally across its range.

Conservation Status

The IUCN, following HBW taxonomy, includes the Rusty-winged Antwren's subspecies in the assessment of the "northern rufous-winged antwren" and has classified it as Least Concern. The species is generally considered fairly common to common, with no immediate threats identified. It is found in many protected areas and extensive tracts of intact habitat.