Colibri améthyste

En bref

  • Scientific Name: Calliphlox amethystina
  • Spanish Name: Estrella amatista
  • Famille : Trochilidae
  • Known Nicknames: Amethyst Woodstar Hummingbird
  • Average Length: 8–10 cm / 3.1–3.9 in
  • Average Weight: 2.5–3.5 g / 0.088–0.123 oz
  • Wingspan: 11–13 cm / 4.3–5.1 in
  • Key Feature: Male's iridescent amethyst throat and elongated tail streamers
  • Primary Diet: Nectarivore (primarily nectar) and occasional small arthropods
  • Range: Eastern and central South America (Venezuela to Argentina)
  • Habitat: Forest edges, open woodlands, gardens, and cerrado savanna
  • Social Structure: Solitary (except during courtship)
  • Nesting/Breeding: Small cup nest built on a horizontal tree branch
  • Statut de conservation : Préoccupation mineure (LC)
  • Évolution démographique : Stable

The Amethyst Woodstar (*Calliphlox amethystina*) is a dazzling hummingbird that lives up to its gemstone name, measuring just 7 to 9 centimeters in length, making it one of the smallest birds in South America. Its most striking feature is the male's brilliant, iridescent amethyst-purple gorget and crown, which flash like living jewels against a backdrop of emerald-green upperparts and a white breast. Unique among its relatives, this species has a deeply forked, swallow-like tail that fans out in flight, and it performs a spectacular U-shaped courtship dive, producing a sharp, metallic "zing" sound with its tail feathers. Despite its tiny size, this woodstar is a fierce aerialist, hovering with incredible precision to feed on nectar from tubular flowers in its rainforest and savanna habitats.

Faits amusants

Despite its diminutive size (one of the smallest birds in the world), the male Amethyst Woodstar performs a bizarre courtship display where it flies in a tight U-shape around the female, making a loud, buzzing “bee-like” sound with its tail feathers that is surprisingly audible over long distances. Its tongue is so long that it must be stored coiled around its skull when not in use, allowing it to reach deep into tubular flowers. Unlike most hummingbirds, it is known to occasionally “hawk” for tiny flying insects mid-air, not just for nectar, and it can enter a state of torpor on cold nights, lowering its heart rate from over 1,000 beats per minute to a near-dormant state to conserve energy.

Habitats et répartition

The Amethyst Woodstar inhabits a variety of open and semi-open environments, primarily within tropical and subtropical zones. Its habitats include forest edges, clearings, secondary growth, savannas, gallery forests, and even cultivated areas like gardens and plantations, ranging from sea level up to around 1,500 meters in elevation. Geographically, its distribution spans much of central and eastern South America, from eastern Colombia, Venezuela, and the Guianas, south through Brazil, eastern Peru, Bolivia, Paraguay, and into northeastern Argentina and Uruguay.

Comportements & Reproduction

Males are solitary and highly territorial, defending feeding sites from rivals with aggressive aerial chases and loud, buzzing wing sounds. Their courtship involves a dramatic U-shaped dive display, where the male climbs high and then plunges toward the female, pulling up at the last moment while producing a sharp, metallic squeak with his tail feathers. Females alone build a tiny cup nest from plant down and spider webs, laying two white eggs. They incubate the eggs for about 14–16 days and feed the chicks solely on regurgitated nectar and small arthropods, with no male involvement in parental care. A unique strategy is their ability to enter torpor on cold nights, reducing metabolic rate to conserve energy for the demands of reproduction.

Alimentation

The Amethyst Woodstar is a specialized nectarivore, feeding primarily on the high-energy nectar of a variety of tubular and cup-shaped flowers, including those from the genera *Erythrina*, *Fuchsia*, and *Heliconia*. It hovers in front of blossoms to extract nectar using its long, extendable tongue. A fascinating aspect of its diet is that it also consumes small insects and spiders, which it catches in flight or gleans from foliage, providing essential protein and fats for growth and reproduction, especially during the breeding season. This hummingbird must feed every 10 to 15 minutes throughout the day to fuel its incredibly high metabolism, consuming up to twice its body weight in nectar daily.

Couleurs

The male Amethyst Woodstar has a brilliant, iridescent amethyst-purple throat patch (gorget) that flashes metallic pink and violet, contrasting with a green-bronze back, white underparts, and a deeply forked tail. The female lacks the purple gorget, showing a white throat with subtle green spotting and a more rounded tail. Both sexes have a distinct white postocular stripe behind the eye, and their greenish-brown upperparts provide camouflage among forest foliage.