Andean Hillstar

Overview

The Andean Hillstar occupies some of the highest elevations of any hummingbird, living on rocky slopes and puna grassland well above the treeline in the central Andes. Its plumage and physiology are adapted to the cold, thin air of this extreme environment.

Adult males show a glittering emerald-green throat bordered below by a violet-purple band, set against a white belly, while females lack these bright gorget colors and appear more subdued overall.

Feather Identification

• Body feathers: Bronze-green above with a notably white belly and undertail region
• Throat feathers: In males, small iridescent scale-like feathers form a glittering green gorget bordered by a violet-purple breast band
• Tail feathers: Somewhat forked, dark with white outer edges in some individuals
• Shaft color: Pale on the white belly feathers, dark above
• Size: Slightly larger and more robust than many lowland hummingbirds, an adaptation to cold high-altitude conditions
• Similar species: The white belly combined with the male's green-and-violet throat pattern separates it from other high-Andes hummingbirds

Plumage Details

Adult males display an iridescent green throat patch bordered by a violet-purple chest band, bronze-green upperparts, and a clean white belly. Females lack the bright gorget and breast band, showing duller green upperparts and pale, sometimes speckled underparts. Juveniles resemble females. There is no strong seasonal plumage shift, though feather wear can dull colors between molts.

Habitat & Range

Andean Hillstars inhabit high-altitude puna grassland, rocky outcrops, and shrub-steppe in the central Andes of Peru, Bolivia, and northern Chile and Argentina, often at elevations above 3,000 meters. The species is largely resident, though some populations make local elevational movements tied to flower availability.

Behavior & Field Notes

This hummingbird feeds on nectar from low-growing high-altitude flowers, often perching to feed rather than constantly hovering, an energy-saving adaptation to the cold climate. It also consumes small insects. At night and in cold conditions it can enter torpor to conserve energy. Nests are built in sheltered rock crevices or under overhangs, offering protection from wind and cold. Calls are thin, high-pitched chips typical of high-altitude hummingbirds.