The Glittering-throated Emerald (*Chionomesa fimbriata*) is a dazzling hummingbird found across the tropical lowlands of South America, renowned for its iridescent throat that flashes brilliant emerald and turquoise in the sunlight. This small bird, measuring about 9–11 cm, has a slender, slightly decurved black bill and a bright white stripe behind the eye, contrasting with its metallic green upperparts and a forked, dark-blue tail. A unique feature is its specialized, fringed tongue, which it uses to rapidly lap nectar from long-tubed flowers, and males perform a distinctive U-shaped display flight during courtship, producing a sharp, metallic *tsip* call. Its ability to hover with precision and its shimmering plumage make it a living jewel of the rainforest canopy.

Faits amusants

Despite its dazzling iridescent throat, the Glittering-throated Emerald has a surprisingly aggressive streak, often seen dive-bombing much larger birds like toucans or hawks that venture near its feeding territory. It can rotate its wings in a full circle during hovering, allowing it to fly backward and even upside down to steal nectar from hard-to-reach flowers. A quirky adaptation is its use of spider webs as a construction material for its tiny cup-shaped nest, which it then camouflages with lichen to look like a knot on a branch. During the breeding season, males perform a pendulum-like display flight, swinging back and forth in front of a female while making a sharp, metallic *tick* sound with their tail feathers.

Habitats et répartition

The Glittering-throated Emerald occupies a broad range of open and semi-open habitats across northern and central South America. It is commonly found in forest edges, clearings, secondary growth, savannas, gardens, and cultivated areas, often near rivers or streams. It avoids dense, humid forest interiors, preferring sunny spots with flowering plants. Its geographical range extends from Colombia, Venezuela, the Guianas, and Trinidad, south through much of Brazil, eastern Peru, and northern Bolivia, and east into the Amazon basin. It also occurs in parts of the Cerrado and Caatinga biomes, adapting well to human-modified landscapes like parks and plantations.

Comportements & Reproduction

The Glittering-throated Emerald is generally solitary outside of breeding, with males defending nectar-rich feeding territories. Mating is a brief, non-monogamous affair: the male performs a U-shaped courtship display, hovering and singing to attract a female, who may mate with multiple males. After copulation, the male provides no parental care. The female alone builds a small cup-shaped nest of plant down and spider webs, often on a horizontal branch tip. She lays two white eggs and incubates them for about 14–15 days, then feeds the chicks regurgitated insects and nectar. A unique reproductive strategy involves the female frequently reusing or repairing old nests for subsequent broods, which can occur multiple times per season in its tropical range. The young fledge after 20–26 days and become independent soon after.

Alimentation

The diet of the Glittering-throated Emerald consists primarily of nectar from a wide variety of flowering plants, which it collects using its long, extendable tongue while hovering. Interestingly, this hummingbird is not a strict specialist; it actively supplements its sugary diet by catching small insects and spiders in flight or gleaning them from foliage, providing essential proteins and fats. Another notable fact is that it exhibits traplining behavior, regularly visiting a circuit of specific flowers in a predictable sequence to maximize energy efficiency.

Couleurs

The Glittering-throated Emerald has a predominantly bright green body with a coppery-bronze sheen on the tail and wings. Its most striking feature is the iridescent, glittering throat patch, which shifts from emerald green to vivid blue or violet depending on the light. A small white postocular spot is present behind the eye, and the underparts are paler, often whitish-gray with green flanks. This hummingbird has no specific camouflage adaptations, as its brilliant colors are used for display rather than concealment.