A hummingbird approximately 10.8 cm long, with simple yet contrasting coloration, featuring a bronzy to golden-green upperparts and entirely white underparts. The back is relatively uniform green, with the crown and wings only slightly darker. The underparts are white from the throat to the undertail coverts, showing only small green patches on the sides of the throat and along the sides of the breast. The tail is relatively short and has broad white areas on the outer feathers, particularly noticeable in flight. Small white spots around the eye stand out against the dark head. The bill is long, slender, and nearly straight; the upper mandible is dark, while the lower mandible is reddish with a dark tip. The legs and iris are dark. The sexes are similar, although females often show slightly creamier tones on the throat and breast. Juveniles are duller and exhibit a greater extent of greenish coloration on the underparts.
Geographic Distribution: This species includes two subspecies distributed along the central Andes. The subspecies chionogaster inhabits the eastern Andean slopes of Peru. The subspecies hypoleuca occurs from southeastern Peru and Bolivia to northwestern Argentina, where it is primarily found in the Yungas of Jujuy, Salta, and Tucumán, extending into Catamarca and La Rioja. There are also isolated records from Santiago del Estero and a documented record from Valle Fértil Department in San Juan Province. It occurs from approximately 200 to 2,300 m above sea level and undertakes local altitudinal movements.
Habitat: It inhabits forest edges, riparian woodlands, wooded ravines, secondary forests, shrublands, and open areas with shrubby vegetation. In northwestern Argentina it is mainly associated with the Yungas, although it also occupies drier transitional habitats and intermontane valleys. In Catamarca and La Rioja it may be found in arid mountainous areas with abundant shrubs and riparian vegetation. It is especially frequent in areas with abundant flowering plants and is commonly associated with streams, ravines, and dense vegetation. In Argentina it ranges from foothill forests to high montane environments, also occupying drier ravines and mountain valleys.
Diet: It feeds primarily on nectar obtained from a wide variety of native and cultivated flowers. It is especially common in habitats rich in flowering shrubs and trees. Its diet is supplemented with small arthropods, which it captures both in flight and from vegetation. It usually feeds alone, moving among flowers at different vegetation levels and making local movements according to resource availability.
Behavior: This is a relatively inconspicuous and unobtrusive hummingbird that often goes unnoticed among vegetation. It moves constantly among flowers, performing short and precise flights. Individuals frequently use exposed perches from which they vocalize for extended periods. Its voice consists of long series of high-pitched, repetitive, and monotonous notes that may gradually accelerate and slow toward the end of the sequence.
Nesting: It builds a small cup-shaped nest made of plant fibers, mosses, and other soft materials, often externally covered with lichens for camouflage. The nest is usually placed on low branches or shrubs. The clutch consists of two white eggs, incubated exclusively by the female.
Conservation Status: Classified as Least Concern (LC) at the international level. In Argentina, it has no national threat category. Although it may be locally common in suitable habitats, its populations depend on the availability of floral resources and the conservation of the habitats it occupies, both in the Yungas and in the mountain systems of northwestern Argentina.
Author of this compilation: María Belén Dri and Diego Carús – 23/06/2026