Elaenia obscura is a large elaenia measuring approximately 18.5 cm in length, with a robust appearance, a relatively small head, and a comparatively long tail. Its plumage is predominantly olive and fairly uniform. The head, back, and tail are dark olive or olive-brown, while the throat and underparts range from pale yellow to olive-yellow, generally becoming paler toward the belly. The wings display two conspicuous whitish or buff wing bars. It has a thin whitish eye-ring and a relatively short, broad bill that is very distinctive, blackish on the upper mandible and with the base of the lower mandible pinkish or flesh-colored, giving it a clearly bicolored appearance. The sexes are similar.
It may be confused primarily with females and juveniles of the Slaty Elaenia (Elaenia strepera), a species with which it may occur locally. However, the Highland Elaenia is larger, has a more uniformly olive coloration, lacks sexual dichromatism, and does not show the slate-gray tones characteristic of the male Slaty Elaenia. It also has a completely different vocalization.
Until a few years ago, the present-day Southern Elaenia (Elaenia sordida), which inhabits the Atlantic Forest and adjacent regions of eastern South America, was treated as a subspecies of this species (Elaenia obscura sordida). Both are now recognized as full species based on vocal, morphological, and biogeographic differences.
Geographic distribution: This species is distributed along the eastern slope of the Andes from southern Ecuador through Bolivia to northwestern Argentina. In Argentina, it is mainly restricted to the Yungas of Jujuy, Salta, Tucumán, and Catamarca provinces. It is most commonly found between 800 and 1,700 m above sea level, although it may occasionally occur at higher elevations.
Although it has traditionally been considered resident, several authors suggest the existence of local or altitudinal seasonal movements, with some populations apparently descending to lower elevations during winter, although these movements remain poorly understood.
Habitat: A characteristic inhabitant of the Yungas, especially montane rainforest and humid montane forests, including alder (Alnus acuminata) woodlands. It frequents forest edges, secondary forests, humid ravines, and small fragments of wooded vegetation, tolerating a certain degree of disturbance. It primarily uses the middle and upper strata of the vegetation.
Diet: It feeds mainly on arthropods as well as a variety of fruits and berries. Food is usually obtained through short flights, hovering, and brief sallies from elevated perches. It generally forages alone or in pairs.
Behavior: Generally solitary, inconspicuous, and difficult to observe. It tends to remain hidden within the foliage more than most species of the genus, although it often perches upright on high, exposed branches for extended periods. It is a rather vocal species, especially at dawn. Its vocal repertoire includes harsh whistles and vibrating or growling notes, often combined into complex phrases.
Nesting: Breeding takes place mainly between November and February. It builds a small cup-shaped nest made of plant fibers, mosses, and lichens, usually lined internally with feathers. The nest is placed on branches or forks of trees and shrubs, typically several meters above the ground. The clutch consists of two white eggs with reddish-brown spots concentrated mainly toward one pole.
Conservation status: This species is classified as Not Threatened (NA) at the national level and as Least Concern (LC) internationally. Although it has a relatively restricted distribution associated with the Yungas, it may be locally common and can tolerate moderately disturbed and fragmented habitats. The loss and degradation of montane forests represent its main potential threat.
Author of this compilation: María Belén Dri and Diego Carús – 15/07/2026