White-bellied Woodstar

Quick Facts

  • Scientific Name: Chaetocercus mulsant
  • Spanish Name: Estrella de vientre blanco
  • Family: Trochilidae
  • Known Nicknames: Mulsant's Woodstar, White-bellied Hummingbird
  • Average Length: 7–9 cm / 2.8–3.5 in
  • Average Weight: 2.5–3.5 g / 0.09–0.12 oz
  • Wingspan: N/A
  • Key Feature: Iridescent green upperparts, white underparts, and a forked tail; male has a glittering violet-red throat patch
  • Primary Diet: Primarily Nectarivore
  • Range: Andes of Colombia, Ecuador, Peru, and Bolivia
  • Habitat: Humid montane forest edges, cloud forests, and adjacent shrubby areas at elevations of 1,500–3,000 m
  • Social Structure: Solitary
  • Nesting/Breeding: Cup-shaped nest on horizontal tree branch or in shrub
  • Conservation Status: Least Concern (LC)
  • Population Trend: Stable

The White-bellied Woodstar (*Chaetocercus mulsant*) is a dazzling miniature hummingbird, barely larger than a bumblebee, that inhabits the cloud forests of the Andes from Colombia to Bolivia. Its most striking feature is the male's iridescent, fiery magenta throat (gorget) that flares into a brilliant, forked tail, contrasting sharply with its snowy-white belly and dark green back. Females lack the vivid throat, sporting a speckled white chest and a shorter tail. A true jewel of the high-altitude mist, this species is renowned for its unique, buzzy, insect-like wingbeats and its hovering flight, often seen feeding on tubular flowers with astonishing precision. Despite its tiny size, it is a fierce defender of its feeding territories, making it both a captivating and resilient spectacle of the Andean canopy.

Fun Facts

Despite its tiny size—barely larger than a bumblebee—the White-bellied Woodstar is a ferocious aerial acrobat, capable of flying backward and hovering in place while beating its wings up to 80 times per second. Its tongue is twice the length of its body, allowing it to probe deep into tubular flowers for nectar, and it enters a state of torpor on cold nights, dropping its heart rate from over 1,000 beats per minute to near-zero to conserve energy. Males perform a quirky courtship dive, shooting up 30 feet in the air then plummeting at high speed, producing a sharp “peep” sound with their tail feathers as they pull up inches from the female.

Habitats & Distribution

The White-bellied Woodstar inhabits a range of montane and subtropical environments, primarily favoring humid to semi-humid forests, forest edges, cloud forests, and adjacent secondary growth or clearings. It is also found in more open, shrubby areas and gardens, often at elevations between 1,500 and 3,000 meters. Its geographical range spans the Andes from central Colombia south through Ecuador and Peru into western Bolivia, with isolated populations also recorded in the coastal mountains of northern Venezuela.

Behaviours & Reproduction

The White-bellied Woodstar is generally solitary outside of breeding, with males defending small feeding territories rather than forming pair bonds. Mating is brief and aerial; the male performs a high, circling display flight with exaggerated wing beats to attract a female, after which copulation occurs mid-air or on a perch. The female alone constructs a tiny cup nest of plant down and spider silk, often on a horizontal branch, where she lays two white eggs. Incubation lasts about 15–16 days, and the female feeds the chicks by regurgitation, with no male involvement in parental care. A unique strategy includes the use of torpor at night by both adults and chicks to conserve energy in their cool Andean habitat, slowing metabolism and body temperature significantly.

Diet

The White-bellied Woodstar primarily feeds on nectar from a variety of flowering plants, which it accesses by hovering in front of blossoms with its rapid, hummingbird-like wingbeats. Its long, specialized tongue allows it to extract nectar from deep, tubular flowers, and it is known to favor plants such as Fuchsia, Salvia, and various epiphytes in its Andean cloud forest habitat. Interestingly, to supplement its high-energy nectar diet, this tiny bird also consumes small insects and spiders, which it catches in flight or gleans from foliage, providing essential proteins and fats. Another fascinating aspect is its ability to enter a state of torpor on cold nights, drastically reducing its metabolic rate to conserve energy when food sources are scarce.

Colors

The male White-bellied Woodstar has a glittering magenta throat and iridescent green upperparts, with a white breast and belly that contrast sharply. Its tail is short, forked, and dark with white outer tips. The female lacks the magenta throat, showing a pale buffy underside and a white-tipped tail. Both sexes have a white postocular stripe. This hummingbird lacks specific camouflage adaptations, relying on its small size and rapid flight for concealment.