Sylphe de King

En bref

  • Scientific Name: Aglaiocercus kingii
  • Spanish Name: Silfo colilargo
  • Famille : Trochilidae
  • Known Nicknames: Sylph, King's Sylph, Long-tailed Sylph
  • Average Length: 15–20 cm / 5.9–7.9 in (including tail)
  • Average Weight: 4–7 g / 0.14–0.25 oz
  • Wingspan: 11–13 cm / 4.3–5.1 in
  • Key Feature: Extremely long, deeply forked iridescent blue tail feathers (up to 12 cm / 4.7 in in males)
  • Primary Diet: Nectarivore (nectar) and occasional small arthropods
  • Range: Andes of Colombia, Ecuador, Peru, and Venezuela
  • Habitat: Humid montane forest edges and clearings, cloud forest, and paramo
  • Social Structure: Solitary (except during breeding)
  • Nesting/Breeding: Small cup-shaped nest built on a branch or fern, often near water
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : Stable

The Long-tailed Sylph (*Aglaiocercus kingii*) is a dazzling hummingbird found in the cloud forests of the Andes, renowned for its extraordinary tail feathers. Males boast two iridescent, elongated outer tail feathers that can reach up to 15 centimeters in length, ending in broad, metallic-blue or violet spatules, which they flaunt in dramatic aerial displays. The bird’s general appearance is equally striking: a glittering emerald-green body, a deep blue throat, and a short, slightly curved black bill. A special feature is its unique, slow-motion flight style during courtship, where the male hovers with its tail feathers sweeping forward like a pendulum, creating a visual spectacle to attract females.

Faits amusants

Despite its tail making up nearly two-thirds of its total body length, the male long-tailed sylph performs a bizarre, bee-like hovering display where it swings this extravagant appendage in a pendulum motion to attract females. It has a uniquely curved bill perfectly matched to drink from tubular flowers like *Fuchsia*, and it will aggressively chase away much larger hummingbirds from its feeding territories, sometimes even clamping onto their feathers mid-air. During the rainy season, these birds have been observed bathing by sliding down wet leaves like tiny, iridescent toboggans.

Habitats et répartition

The Long-tailed Sylph inhabits humid montane forests, cloud forests, and forest edges, frequently occurring in areas with abundant epiphytes and flowering plants like bromeliads and orchids. It is also found in secondary growth and shrubby clearings adjacent to mature forest, typically at elevations between 1,000 and 2,500 meters. Its geographical range extends along the eastern slope of the Andes from western Venezuela through Colombia, Ecuador, and into northern Peru.

Comportements & Reproduction

The Long-tailed Sylph is generally solitary outside of breeding. Males are highly territorial, defending specific feeding areas and display perches to attract females. During courtship, the male performs a dramatic U-shaped dive in front of a perched female, producing a loud, buzzing sound with his tail feathers. Mating is brief and promiscuous; the male takes no part in nesting or parental care. The female builds a small, cup-shaped nest from plant down and spiderwebs, often attached to a vertical branch or leaf tip. She lays two white eggs and incubates them alone for approximately 15–16 days. A unique reproductive strategy involves the female relying on a highly specialized, energy-rich diet of nectar and small arthropods to fuel the demanding process of egg-laying and chick-rearing, often timing her breeding to coincide with peak flower availability.

Alimentation

The Long-tailed Sylph primarily feeds on nectar from a variety of long-tubed, brightly colored flowers, which it accesses with its specialized, extendable tongue while hovering. A fascinating aspect of its diet is its heavy reliance on high-energy nectar to fuel its extremely rapid metabolism and energetically costly hovering flight, requiring it to visit hundreds of flowers daily. Unlike many other hummingbirds, it is also known to consume a significant amount of small insects and spiders, actively gleaning them from leaves and bark or catching them in mid-air, which provides essential protein, fats, and amino acids during breeding season and for chick development.

Couleurs

The male Long-tailed Sylph is iridescent emerald green with a brilliant blue throat patch, a deep violet crown, and elongated, forked tail feathers that are metallic blue-black. The female is less vibrant, with a green back, white underparts heavily spotted with dark green, and a much shorter tail, providing camouflage among foliage. Both sexes have a white postocular stripe.