Emerald-bellied puffleg

Eriocnemis aline

Cali Valle Del Cauca Colombia

Quick Facts

  • Scientific Name: Eriocnemis aline
  • Spanish Name: Calzadito pechiblanco
  • Family: Trochilidae
  • Known Nicknames: Emerald-bellied puffleg
  • Average Length: 8–9 cm / 3.1–3.5 in
  • Average Weight: 4.0–4.5 g / 0.14–0.16 oz
  • Wingspan: 10–12 cm / 4.0–4.7 in
  • Key Feature: White leg puffs and a brilliant emerald-green belly with a white pectoral patch
  • Primary Diet: Nectarivore (Nectar and small arthropods)
  • Range: Andean regions of Colombia, Ecuador, and Peru
  • Habitat: Humid montane forests and cloud forests
  • Social Structure: Solitary and territorial
  • Nesting/Breeding: Cup nests made of moss and lichen
  • Conservation Status: Least Concern (LC)
  • Population Trend: Stable

The Emerald-bellied puffleg (*Eriocnemis aline*) is a breathtaking hummingbird native to the humid montane forests of the Andes, spanning from Colombia to Peru. This small avian gem is most famous for its namesake "pufflegs"—conspicuous, snowy-white downy feathers that encircle its legs like tiny cotton balls. Its general appearance is dominated by shimmering, metallic emerald-green plumage, which is dramatically interrupted by a brilliant, large white patch on the center of its breast that glitters in the dappled sunlight. Beyond its striking coloration, this species features a deeply forked, dark bluish-black tail and a slender bill perfectly adapted for sipping nectar from high-altitude blooms. This combination of iridescent greens and stark whites makes it one of the most visually captivating and easily identifiable residents of the cloud forest canopy.

Fun Facts

This hummingbird is famous for its distinctive "wooly boots," which are actually dense tufts of white down feathers that serve as insulation against the frigid temperatures of high-altitude cloud forests. Beyond its fashion sense, the species is fiercely territorial, often engaging in a rhythmic "shuttling" display where it zips back and forth like a pendulum to ward off rivals. Adding to its visual flair, it possesses a brilliant, highly reflective white breast patch that functions like a signal mirror, flashing intensely during courtship flights to grab attention in the misty canopy.

Habitats & Distribution

This species is found along the eastern slopes of the Andes, stretching from central Colombia through Ecuador to central Peru. Its range is relatively narrow and follows the high-altitude mountain chains where specific climatic conditions are met. Within these regions, it occupies localized areas of suitable terrain, typically occurring at elevations between 2,300 and 2,800 meters, though it is occasionally recorded as low as 1,700 meters. It primarily inhabits humid montane forests and cloud forests, showing a preference for dense undergrowth and forest edges. These environments are characterized by high moisture levels and frequent mist or fog. In addition to primary forests, it can also be found in secondary growth and shrubby clearings where it searches for nectar-producing flowers.

Behaviours & Reproduction

Primarily solitary and fiercely territorial, these birds aggressively defend nectar-rich floral patches against intruders. Their social structure is characterized by independence, with interactions limited almost exclusively to brief mating displays. Males utilize their distinctive white leg puffs during aerial maneuvers to attract females, participating in a polygynous mating system where they provide no parental care. The female handles all aspects of reproduction, from weaving a cup-shaped nest of moss and lichen to incubating the eggs and feeding the young. She typically selects sheltered locations in the forest undergrowth to protect the brood from predators and harsh weather. This division of labor allows males to focus on defending high-quality territories while the female ensures the development and fledging of the next generation.

Diet

The Emerald-bellied puffleg primarily sustains itself on a nectar-rich diet sourced from a variety of flowering plants, particularly those within the Ericaceae, Rubiaceae, and Melastomataceae families. These hummingbirds are known to frequent both tubular and open-faced blossoms, using their specialized, long tongues to extract energy-dense fluids that fuel their high-metabolism flight. Interestingly, while nectar provides their primary caloric intake, they also supplement their diet with small insects and spiders, which they catch mid-air or glean from foliage to obtain necessary proteins and minerals. A fascinating aspect of their feeding behavior is their adaptability; they can act as "trap-liners," following established routes between scattered floral resources, or fiercely defend specific high-quality flower patches from other nectar-seeking competitors.

Colors

The Emerald-bellied puffleg features shimmering metallic green plumage with a large, brilliant white patch on the center of its breast. It is distinguished by signature dense, snowy-white feather "puffs" around its legs and a dark, deeply forked tail. While its iridescent green provides camouflage within humid forest canopies, the stark white markings serve as unique visual identifiers.