Ecuadorian Hillstar

Quick Facts

  • Scientific Name: Oreotrochilus chimborazo
  • Spanish Name: Colibrí del Chimborazo
  • Family: Trochilidae
  • Known Nicknames: Chimborazo Hillstar
  • Average Length: 11.5–13 cm / 4.5–5.1 in
  • Average Weight: 7.6–8.3 g / 0.27–0.29 oz
  • Wingspan: 14–15 cm / 5.5–5.9 in
  • Key Feature: Iridescent violet-blue head hood (males) and slightly decurved black bill
  • Primary Diet: Nectarivore and Insectivore
  • Range: Andes of Ecuador and extreme southern Colombia
  • Habitat: High-altitude paramo grassland and alpine scrub (3,500 to 5,200 meters elevation)
  • Social Structure: Solitary
  • Nesting/Breeding: Sheltered rock faces, cliffs, or caves
  • Conservation Status: Least Concern (LC)
  • Population Trend: Decreasing

The Ecuadorian Hillstar (*Oreotrochilus chimborazo*) is an extraordinary hummingbird uniquely adapted to the freezing, high-altitude páramo grasslands of the Ecuadorian Andes, thriving at elevations up to 5,000 meters. The male is particularly striking, boasting a glittering, iridescent violet-blue hood contrasted by a snow-white breast and a dark collar, while the female sports a more subdued, camouflaged olive-green plumage. To survive the extreme alpine cold and thin air, this resilient bird has developed remarkable adaptations: it saves precious energy by clinging to its favorite orange *Chuquiraga* flowers to feed rather than hovering, and it enters a state of deep nocturnal torpor—drastically lowering its body temperature and heart rate—to withstand the sub-zero mountain nights.

Fun Facts

To survive freezing Andean nights at altitudes up to 16,000 feet, this extreme-altitude specialist enters a nightly state of profound torpor, dropping its body temperature to near-freezing and slowing its heart rate from 1,000 beats per minute to just 30. To conserve precious energy in the thin, windy air, it rarely hovers, choosing instead to climb and cling directly to its favorite orange *Chuquiraga* flowers while feeding. It is also a cave-dweller of the hummingbird world, building thick, heavily insulated nests of moss and rabbit fur on protected rock walls that are so durable they are often passed down and reused by successive generations.

Habitats & Distribution

This high-altitude specialist is restricted to the Andes of Ecuador, with a small, localized population extending into the extreme south of Colombia. Its geographical range is highly fragmented, as it is primarily confined to the slopes of isolated volcanic peaks, including Mount Chimborazo, Cotopaxi, Antisana, and Pichincha. These distinct populations function almost like islands, separated by lower-elevation valleys that the species rarely crosses. It inhabits the cold, windswept alpine grasslands known as the *páramo*, typically at extreme elevations between 3,500 and 5,200 meters above sea level, right up to the snowline. Within this harsh, low-oxygen environment, it is strictly associated with rocky cliffs, ravines, and scrublands dominated by the chuquiragua plant (*Chuquiraga jussieui*). This spiny shrub is vital to its survival, serving as its primary food source and providing sheltered microclimates for nesting and roosting during freezing nights.

Behaviours & Reproduction

Highly territorial and solitary, this species exhibits a social structure centered around the aggressive defense of feeding territories, particularly by males guarding key nectar sources. To survive the freezing night temperatures of its high-altitude habitat, it relies on a vital behavioral and physiological adaptation: entering a state of deep nocturnal torpor inside caves or deep rock crevices, which drastically lowers its metabolic rate and body temperature. Mating is polygynous, with males performing dramatic aerial hovering displays to showcase their brilliant iridescent plumage to prospective mates. The female assumes all parental duties, employing a specialized reproductive strategy to protect her offspring from the harsh alpine climate. She constructs a remarkably bulky, heavily insulated cup nest using moss, plant down, and animal wool, securing it to the walls of caves or steep rocky cliffs. This strategic nesting in sheltered microclimates ensures the survival of her typical clutch of two eggs against extreme cold and wind.

Diet

The Ecuadorian Hillstar has a highly specialized diet centered almost exclusively on the nectar of the orange-flowered *Chuquiraga jussieui*, a hardy shrub native to the extreme high-altitude Andean paramo. Because hovering in the thin, freezing air at altitudes up to 5,000 meters is incredibly energy-intensive, this unique hummingbird has adapted by perching directly on the sturdy stems of these flowers to feed rather than hovering like most other species. To supplement this carbohydrate-rich nectar with essential protein, the Ecuadorian Hillstar also hunts small insects and spiders, either catching them in mid-air or gleaning them from rock faces and low vegetation. Due to the scarcity of food in its harsh habitat, individuals are fiercely territorial, aggressively defending their preferred patches of *Chuquiraga* bushes from competitors to secure their vital energy sources.

Colors

The male Ecuadorian Hillstar features a striking, iridescent violet-blue hood, olive-green upperparts, and a white breast split by a dark vertical chest stripe. In contrast, the female exhibits dull olive-green upperparts and a finely speckled greyish-white throat and underparts, providing vital camouflage against the rocky, low-vegetation paramo habitat where they nest. Both sexes have dark wings and white-sided tails, with the male's vivid, high-contrast coloration serving as a bold signal in their barren alpine environment.