The Ruddy-tailed Flycatcher, known scientifically as Terenotriccus erythrurus, is a diminutive passerine bird that graces the family Tityridae with its presence. This avian wonder is the sole representative of its genus, Terenotriccus, and is sometimes considered part of the Myiobius genus, though it stands apart in voice, behaviour, and structure.
Adults of this species measure a compact 9.0–10.2 cm in length and tip the scales at a mere 7 g. They are adorned with grey-olive upperparts, while their rump, tail, wings, and eye ring boast a rich rufous hue. The throat presents a buff colour, transitioning to cinnamon on the breast and fading to a pale buff on the belly. Both sexes are similarly attired, with juveniles displaying a brighter plumage above and a browner tail and breast.
The Ruddy-tailed Flycatcher favours the lushness of wet mountain forests and the adjacent tall second growth. It thrives from sea level up to 1,000 m altitude, and occasionally higher, up to 1,200 m.
This species has a broad range, from southeastern Mexico to northern Bolivia, north-central Brazil, and the Guianas. It is found east of the Andes in the Amazon Basin and the Guianas, and to the west of the Andes in Colombia and Ecuador, extending into Central America.
A creature of solitary habits, the Ruddy-tailed Flycatcher is not one to frequently join mixed-species feeding flocks. It exhibits a preference for insects, particularly leafhoppers, which it skillfully plucks from foliage or captures in mid-air with acrobatic finesse.
The auditory repertoire of this species includes a distinctive "see-oo see" call and an insistent "eek eek eek eek eek" song. In a subtle display, it may flick both wings upward, producing a faint whirring sound.
The female Ruddy-tailed Flycatcher is solely responsible for constructing the nest—a pear-shaped pouch of plant fibres and leaves with a visored side entrance, suspended 2–6 m high in the undergrowth from a twig or vine. She incubates the two chocolate-blotched white eggs for 15–16 days until they hatch, without any assistance from the male in caring for the eggs or the young.
While there are no specific similar species mentioned, the Ruddy-tailed Flycatcher can be distinguished from other flycatchers by its unique colouration and size.
The diet of the Ruddy-tailed Flycatcher consists mainly of insects, with a particular taste for leafhoppers. It employs both perching and aerial tactics to secure its prey.
The International Union for Conservation of Nature (IUCN) has classified the Ruddy-tailed Flycatcher as Least Concern, indicating that, for now, this species does not face an immediate threat of extinction in the wild.