Southern White-fringed Antwren

The Southern White-fringed Antwren, Formicivora grisea, is a diminutive and active insectivorous bird, part of the Thamnophilidae family, commonly known as "typical antbirds". This species exhibits sexual dimorphism, with males and females sporting distinct plumage patterns.

Identification Tips

Adult males of the nominate subspecies are characterized by a striking white supercilium that extends down the neck and flanks, contrasting with their dark grayish-brown upperparts and black underparts with white underwing coverts. Females, on the other hand, display a buff supercilium and lighter cinnamon underparts. Subadult males initially resemble females but gradually acquire the adult male's darker throat and breast.

Habitat

The Southern White-fringed Antwren is found in a variety of wooded landscapes, preferring the understorey to mid-storey at the forest's edges. It is adaptable to different types of vegetation, including mangroves, second growth, riparian vegetation, tropical deciduous forest, and restinga scrublands.

Distribution

This species has a disjunct distribution across South America, with populations in northern Brazil, the Guianas, parts of Amazonian and eastern Brazil, Colombia, and Venezuela. It is typically found at elevations below 1,000 meters but can be found up to 1,600 meters in Venezuela.

Behaviour

The Southern White-fringed Antwren is a year-round resident, foraging actively in dense vegetation for insects and spiders. It is often seen foraging alone, in pairs, or in family groups, and occasionally joins mixed-species feeding flocks.

Song & Calls

The bird's vocal repertoire includes a "monotone song" of soft chup notes, a variable complex note described as "churet" or "chuweet", and a liquid phrase "kip-chrup". Both sexes sing, typically from within the concealment of foliage, primarily in the morning.

Breeding

Breeding seasons vary across its range, with nesting occurring between July and March. The nest is a suspended cup made of grass stems and plant fibers. Clutch size is typically two eggs, but details on incubation and parental care are not well documented.

Similar Species

The Northern White-fringed Antwren (Formicivora intermedia) was once considered conspecific but has been separated based on distinct vocalizations.

Diet and Feeding

The diet consists of a wide array of insects and spiders. The antwren employs various foraging techniques, including gleaning from foliage and making short sallies to catch moths in flight.

Conservation Status

The IUCN has classified the Southern White-fringed Antwren as Least Concern. It has a large range and is considered uncommon to fairly common within it. The species is found in several protected areas and is less vulnerable to habitat disturbance due to its adaptability to second-growth and edge habitats.