The Rio Branco antbird is a Critically Endangered bird species in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is found in Brazil and Guyana.
Region
Northern Amazonia (Rio Branco–Takutu basins of Brazil and adjacent Guyana)
Typical Environment
Occurs patchily along the Rio Branco and its tributaries in northern Brazil, spilling into adjacent parts of southwestern Guyana. It favors dense river-edge thickets, secondary riparian scrub, and gallery forest understory, often on sandy or seasonally flooded substrates. The species uses vine tangles, young regenerating growth, and edges of savanna–forest ecotones. It is generally absent from tall, closed-canopy terra firme forest away from waterways.
Altitude Range
0–300 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 1/5
A highly range-restricted antbird, it is tied to dense riparian scrub along the Rio Branco and nearby drainages. Pairs often duet, with male and female giving contrasting notes. It may attend army-ant swarms opportunistically but more often forages independently in low, tangled vegetation. Its tiny range and ongoing habitat loss from fire and agricultural expansion have made it Critically Endangered.
Temperament
secretive and territorial
Flight Pattern
short rapid wingbeats close to the ground
Social Behavior
Typically found in pairs that maintain small territories year-round. Pairs engage in antiphonal duets and remain in dense cover while foraging. Nests are placed low in shrubs or tangles near water, with both sexes participating in care.
Migratory Pattern
Resident
Song Description
A clear, whistled series from the male, often accelerating or slightly rising, answered by a harsher rattle or churring notes from the female. Calls include sharp chips and scolds given from cover.
Plumage
Male is mostly glossy black with contrasting small white spots or bars on the wing coverts; tail is black. Female is warm rufous-brown above with buffy to cinnamon underparts and a darker tail; wings show faint pale spotting. Both sexes have a slender, slightly hooked bill suited to gleaning insects.
Diet
Feeds primarily on arthropods such as insects and spiders, gleaned from leaves, twigs, and vine tangles. It makes short sallies to pick prey from foliage or the ground and occasionally probes dead leaves. It may sometimes attend army ant swarms to capture flushed prey but is not an obligate follower.
Preferred Environment
Forages in dense understory of river-edge scrub, gallery forest margins, and regenerating thickets. Most activity occurs within 0–2 m of the ground in shaded, tangled vegetation near water.
