Bronze-tailed Thornbill

Colombia

Jul 17

Bronze-tailed Thornbill (Chalcostigma heteropogon)

Name Origin:
The genus name Chalcostigma comes from the Greek chalkos meaning “bronze” and stigma meaning “mark” or “spot,” referring to the metallic throat patches of these mountain hummingbirds. The species name heteropogon combines heteros meaning “different” and pogon meaning “beard,” describing the bird’s distinctive, multicolored throat.

Quick Facts

🪶 Length: 9–10 cm (3.5–3.9 in)
⚖️ Weight: 3–4 g (0.10–0.14 oz)
🌎 Range: Andes of Colombia and northwestern Venezuela
🧭 Elevation: 2,800–4,000 m (9,200–13,100 ft)
🌸 Diet: Nectar and small insects
🏡 Habitat: Páramo, elfin forest, and high-elevation shrubby slopes
🧬 Clade: Lesbiini "Coquettes and Thornbills" (high-Andean specialists)
📊 Status: Least Concern (IUCN)

Subspecies & Distribution

Monotypic species with no recognized subspecies.

Distribution: Found in the Eastern Andes of Colombia from Norte de Santander south to Cundinamarca, and in northwestern Venezuela in the Mérida Andes. It inhabits high-altitude páramo shrublands and upper montane scrub between 2,800 and 4,000 meters, where it feeds among flowering shrubs and Espeletia plants.

Species Overview

The Bronze-tailed Thornbill is one of the most striking hummingbirds of the high Andes. Its glowing purple throat and bronzy tail stand out against the gray-green tones of the páramo. Though small, it is a hardy mountain species that thrives in thin, cold air and frequent mist, feeding tirelessly on alpine flowers.

Male Description:
The male has bronzy-green upperparts, a shining violet-purple gorget, and grayish underparts with a soft green wash. The tail is bright bronze with rufous and copper reflections. The bill is short and straight, well-suited to tubular flowers found in its alpine habitat.

Female Description:
The female resembles the male but is duller overall. She has a paler throat with faint violet or buffy spotting, lighter underparts, and a bronzy-green tail with pale tips. Her plumage blends well with the páramo vegetation.

Habitat & Behavior:
This species inhabits open páramo and shrubby slopes near the tree line, often foraging along the edges of elfin forests. It feeds primarily on nectar from Espeletia, Puya, and Bomarea, and supplements its diet with small insects. The Bronze-tailed Thornbill is territorial, perching on tall shrubs to watch over its feeding grounds. It flies swiftly between flowers, often pausing briefly to hover. At night, it may enter torpor to conserve energy in cold conditions.

Conservation Note:
The Bronze-tailed Thornbill is listed as Least Concern by the IUCN but can be locally uncommon. Its specialized high-Andean habitat is vulnerable to grazing, fires, and agricultural expansion. Protecting páramo ecosystems and maintaining floral diversity is essential for the survival of this resilient and radiant Lesbiini hummingbird.