Blue-mantled Thornbill Hummingbird Species

The blue-mantled thornbill is a small hummingbird found in the tropical regions of South America. With its vibrant iridescent blue plumage and long, downcurved bill, this tiny bird is considered one of the most strikingly beautiful hummingbirds in the world. In this article, we will explore the identification, distribution, habitat, diet, behavior, breeding, conservation status and interesting facts about this jewel-like species.


The blue-mantled thornbill measures only 8-10 cm in length and weighs just 2-3 grams, making it one of the smallest hummingbird species. The male has glossy iridescent blue plumage on its head, back, rump and uppertail, with a bright blue-violet throat patch. The female is similar but has green plumage on the head and back instead of blue, and lacks the male’s vivid throat coloring. Both sexes have a long black bill with a distinctive downward curve, and white underparts with greenish sides. The legs are short and black. Juveniles resemble adult females but have buffy edges on the feathers.

This hummingbird’s sparkling blue plumage distinguishes it from all other South American hummingbirds except the similar, but larger, blue-throated starfrontlet. The blue-mantled thornbill can be identified by its smaller size, longer bill, buffy white breast band and lack of a white spot behind the eye.

Distribution and Habitat

The blue-mantled thornbill is found along the eastern slopes of the Andes Mountains in South America. Its range extends from western Venezuela through Colombia, Ecuador and Peru. It occurs at elevations between 2400-4300 meters, inhabiting humid montane forest and elfin woodland, as well as scrublands and mountain meadows with scattered trees and shrubs.

In Colombia, this species is fairly common on both slopes of the Central and Eastern Andes. In Ecuador, it is widespread on the eastern Andean slopes and high elevation valleys. In Peru, it is localized to a few patches of elfin forest and scrub. Across its range, the blue-mantled thornbill prefers habitats with an abundance of flowering plants and facilitates movement between nectar sources.

Diet and Feeding

Like all hummingbirds, the blue-mantled thornbill has a specialized diet consisting mostly of nectar from flowers. It uses its long, slender bill to drink nectar from a variety of Andean flowering plants such as fuchsias, lupines, angel’s trumpets and other tubular blossoms. The bill allows the bird to reach nectar at the base of long corollas. This species prefers to feed at flowers located high in the forest canopy.

The blue-mantled thornbill supplements its diet with small insects including beetles, ants, wasps and spiders. It gleans insects from leaves and branches or snatches them out of the air. The bird’s fast, acrobatic flight enables it to pursue insects in mid-air.


The blue-mantled thornbill is active and energetic, constantly fluttering its tiny wings to stay aloft. It hovers in front of flowers when feeding and engages in chasing flights with other hummingbirds. Despite its small size, this species can be aggressive, chasing larger hummingbirds from their perches or favored nectar sources.

When not feeding, these hummingbirds perch on small exposed branches to rest. As with other Andean hummingbirds occupying the high elevation cloud forest, they are adapted to tolerate cold temperatures and periods of torpor to conserve energy overnight.

Males are territorial and use ritualized display flights to defend feeding areas. They perform aerial maneuvers and dives up to 5 meters in height, with their colorful throat patches exposed. Their wings produce a buzzing “chirps” during these displays.


The breeding season for the blue-mantled thornbill occurs from April to August in Colombia, coinciding with periods of increased flower abundance. Courtship displays by the male involve rapid hovering and aerial pursuits of the female.

The tiny cup-shaped nest is constructed by the female from soft plant fibers, lichens and moss, bound together with spider webs. It is situated on a high horizontal branch, attached to a vertical trunk or tucked into thick vegetation 10-20 meters above ground.

The female lays just two tiny white eggs. She incubates the eggs for about 16-19 days. The chicks are fed regurgitated food by both parents, and leave the nest at 20-26 days old. The female may raise a second brood in one season.

Conservation Status

The blue-mantled thornbill has a relatively limited distribution but is fairly common throughout its range. Its remote montane forest habitat means there are no major threats to the overall population at present. For these reasons, the species is evaluated as Least Concern on the IUCN Red List of Threatened Species. However, some localized declines have occurred in Ecuador and Venezuela due to habitat loss from land conversion to agriculture. Ongoing habitat protection is needed to ensure healthy numbers across its Andean range.

Interesting Facts

– This hummingbird’s scientific name Chalcostigma comes from the Greek words “chalcos” meaning copper or bronze and “stigma” for spot or mark, in reference to its shiny bluish plumage. The species name stanleyi honors the American ornithologist Hiram Stanley.

– Male blue-mantled thornbills produce a distinctive humming “song” with their wings during breeding displays. The feather shafts and surfaces vibrate to create this buzzing sound.

– Along with the Long-tailed Sylph, the blue-mantled thornbill has the longest bill proportional to its body size of any hummingbird species. This allows it to feed on flowers with deep corollas.

– Tiny feathery tufts above its eyes may help channel airflow while the bird is feeding at flowers.

– This species and the similar blue-throated starfrontlet occasionally hybridize where their ranges overlap in Colombia and Ecuador. The resulting hybrids show a mix of plumage features from both species.

In summary, the dazzling blue-mantled thornbill is a diminutive yet distinctive hummingbird, adapted to the cold, high mountain forests of the northern Andes. While relatively common, conservation measures are needed to protect its specialized habitat and ensure this gem-like bird continues to glisten over its Andean realm.