Flame-throated Sunangel Hummingbird Species

The flame-throated sunangel (Heliangelus spectabilis) is a medium-sized hummingbird found in the Andes Mountains of South America. With its vibrant orange throat feathers and glittering green crown, this species is aptly named for its dazzling plumage. The flame-throated sunangel is a high elevation specialist, inhabiting the treeless mountainsides and scrublands above 10,000 feet. Here in the cool, thin air it flies with a rapid wingbeat, probing flowers with its slender curved bill. The flame-throated sunangel has several adaptations that allow it to thrive in the harsh conditions of the high Andes.

Range and Habitat

The flame-throated sunangel has a relatively small range confined to the Andes Mountains. Its range stretches from central Peru south through Bolivia to northwestern Argentina. Within this range it occurs in two disjunct populations—one in the Central Andes and another in the Southern Andes. It is found in various mountain chains including the Cordillera Blanca, Cordillera Vilcanota, and Cordillera Apolobamba.

This species inhabits the high elevation habitats known as elfin forest, mountain shrubland, and puna grasslands. Elfin forest is a stunted, windswept woodland that occurs above treeline. The twisted trunks and gnarled branches are draped in hanging lichens and mosses. Mountain shrubland is composed of small woody shrubs, scattered trees, and lush patches of herbs and grasses. Puna grassland is an expansive ecosystem of grasses and small plants that resembles alpine tundra. The flame-throated sunangel prefers forest edges, scrubby clearings, rocky slopes, and ravines from 10,000 to 17,000 feet in elevation.


The flame-throated sunangel is a medium-sized hummingbird reaching lengths of 3.5 to 4 inches and weighing around 5 grams. As its name suggests, the male has fiery orange feathers covering its throat that glitter as the bird turns its head. The rest of the body is primarily an iridescent emerald green above and grayish white below. A splash of bright yellow marks the lower belly. The forked tail is rufous-colored with a wide black subterminal band. The bill is slender, curved, and black.

The female is similar to the male, but the orange throat feathers are slightly duller and less extensive. Immature birds resemble adult females but have buffy scaling on the throat and breast. The flaming orange throat patch and glittering green crown make the male flame-throated sunangel nearly unmistakable. The similar Amethyst-throated Sunangel has an amethyst violet rather than orange throat.

Diet and Feeding

Like all hummingbirds, the flame-throated sunangel feeds on nectar and tiny insects. It uses its specialized tubular tongue to drink nectar from the flowers of high altitude plants such as the red-floweredColombian giant lichen and Andean hillstar. It also hawks small insects such as flies, beetles, and gnats captured in mid-air or gleaned from leaves and branches.

The long, curved bill of the flame-throated sunangel is adapted for accessing nectar from specialized flowers. When feeding, it hovers in front hummingbird-pollinated flowers and inserts its bill deep inside to probe for nectar. The bill’s flexible tip allows it to lap up nectar. Small stiff feathers around the bill, called rictal bristles, may help protect its eyes from pollen and petals.

Many of the flowers preferred by flame-throated sunangels are tubular in shape, reflecting the coevolution between deep-billed hummingbirds and long, curved flowers. This exquisite match benefits both the bird, which gains access to nutritious nectar, and the plants, which are pollinated by the bird.

Unique Adaptations

Life at high elevations poses special challenges for hummingbirds like the flame-throated sunangel. The combination of cold temperatures, fierce winds, intense sunlight, and low oxygen makes existence at altitudes over 10,000 feet testing. The flame-throated sunangel possesses special adaptations that help it survive and even thrive in the harsh puna environment.

One key adaptation is the ability to enter torpor, a state of decreased physiological activity characterized by reduced heart rate, breathing, and metabolism. At night and during cold spells, the sunangel reduces its body temperature and enters an energy-saving torpor. This helps conserve calories and reduce the risk of starvation in the flower-sparse habitat.

The flame-throated sunangel also has a high ratio of mitochondria to cell volume, which allows it to produce energy efficiently in the low oxygen conditions. It has an elevated hemoglobin concentration in its blood, improving its ability to extract oxygen from the thin air. Its wings are shaped to provide excellent lift for hovering at altitude, an ability vital for feeding on nectar.

Behavior and Breeding

The flame-throated sunangel lives alone or in pairs, defending flower-rich territories from other hummingbirds. When a rival intrudes, the resident bird performs aggressive aerial displays, rapidly climbing then diving while flashing its colorful throat. The species is highly territorial despite the relatively few flowering plants that occur naturally in its high elevation habitat.

Little is known about the breeding behavior of this species. Breeding apparently coincides with peaks in flower abundance from July to September. The nest is a small cup of moss and plant fibers attached to a vertical stem or root in a sheltered location. Typical clutch size is two eggs which are incubated by the female for about 16-19 days. The chicks are fed regurgitated nectar and insects by the female. Young sunangels apparently leave the nest at 22-26 days old.

Threats and Conservation

The remote, inaccessible habitat of the flame-throated sunangel has offered it protection from many threats facing other bird species. However, some concerning trends put the species at risk. Global warming poses a major threat as warmer temperatures drive plants and animals upwards, reducing available habitat. Insect prey populations also decline at higher elevations as temperatures rise.

Deforestation, mining, and agricultural expansion in the Andes degrade sunangel habitat and increase fragmentation. Overgrazing by livestock reduces flowering plants. Some small populations are threatened by tourism developments. The flame-throated sunangel is now classified as Near Threatened by the IUCN due to its small range and declining habitat. Protecting high elevation ecosystems will be crucial for the persistence of this unique Andean jewel. More surveys and monitoring are needed to assess populations across its range. Sustainable grasslands management and control of development in protected areas will also help secure the flame-throated sunangel into the future.


Few birds can rival the flame-throated sunangel’s dazzling beauty. Its fiery plumage seems to glow even in the dreary, fog-shrouded Andean backdrop. But beyond its good looks, it is a master of extreme environments and a vital pollinator. As an endangered keystone species, protecting this specialized hummingbird is crucial for maintaining the health of puna ecosystems. The survival of the flame-throated sunangel provides a measure of hope that these threatened sky island habitats will endure for future generations to appreciate.