Introduction
The Blue-throated Hillstar (Oreotrochilus cyanolaemus) is a critically endangered hummingbird endemic to a small area of the high Andes in southwestern Ecuador. It was discovered in 2017 and formally described in 2018. The species occupies cold, windswept páramo and is especially associated with flowering shrubs and rocky terrain around the Cordillera de Chilla-Tioloma-Fierro Urco.
Physical Description
The Blue-throated Hillstar is a medium-sized hummingbird, measuring approximately 13 to 14 centimetres in length. It has the compact body, relatively long bill and pointed wings typical of the hillstars, a group adapted to life in open, high-elevation habitats.
The sexes are strongly dimorphic. The adult male has a vivid, iridescent ultramarine-blue throat, an iridescent teal-green head and upperparts, and mainly white underparts. A narrow black band separates the blue throat from the breast, while another dark stripe runs down the centre of the belly.
The female is mainly shining teal-green to bronze-green above, with dusky markings on the flanks, chin and upper throat. The lower throat is largely whitish but carries scattered iridescent blue-green feathers. Immature males resemble females until the adult throat pattern develops.
Range and Habitat
The species is endemic to southwestern Ecuador and is known from a very small area in the western Andes, particularly the Cordillera de Chilla-Tioloma-Fierro Urco. It has been recorded at roughly 3,300 to 3,800 metres above sea level, although local observations and published accounts vary slightly by site.
Blue-throated Hillstars inhabit páramo, a high-altitude ecosystem of grassland, boggy ground, low shrubs, mosses, rocky outcrops and small streams. They are frequently associated with flowering Chuquiraga jussieui, locally known as chuquiragua, as well as other shrubs and bromeliads. Males often use shrubby patches and exposed perches, while females may occur near more open ground, streams and low vegetation.
The species is considered non-migratory, although individuals may make local movements between flowering patches and suitable habitat. Its extremely restricted distribution means that fire, grazing, plantations and other changes in páramo habitat can affect a large proportion of the global population.
Where to See This Species
Cerro de Arcos Reserve, Loja Province, Ecuador
Cerro de Arcos is the most reliable documented place to look for the Blue-throated Hillstar. The reserve protects high-elevation páramo containing rocky arches, shrubs, streams and flowering Chuquiraga, and it was established specifically to safeguard habitat for this species. Birds may be encountered around flowering shrub patches and rocky areas, particularly during suitable weather and flowering periods. Visits should be arranged in advance through the reserve’s local conservation and tourism partners, and conditions can be cold, windy and wet.
Nearby accommodation: Guambusari and surrounding rural communities provide the nearest practical base. Visitors should arrange local guest-house, lodge or camping accommodation in advance, as facilities are limited.
Behaviour and Diet
Blue-throated Hillstars spend considerable time perched, conserving energy in an environment where thin air makes sustained hovering more demanding. Rather than hovering continuously in front of flowers, they commonly cling to branches or flower stems, feeding sideways or even upside down. They may also make short flights between feeding and perching sites.
The principal recorded food plant is Chuquiraga jussieui. The birds also visit other flowering shrubs, including Macleania rupestris, and have been observed feeding from Puya bromeliads and other plants. Insects, including flies, provide additional protein and are sometimes taken during short aerial sallies.
Males can be territorial and may chase immature males or compete with other hummingbirds at concentrated food sources. The species is generally associated with rocky outcrops, low shrubs, streams and exposed perches. Like other high-Andean hummingbirds, it is thought to use nocturnal torpor in sheltered crevices to reduce energy expenditure during cold nights.
Breeding information remains limited. Known nests have been found in caves or rock crevices, where they are sheltered from wind and rain. The open-cup nests are made from materials including moss, rootlets, twigs, dry leaves, feathers and soft bromeliad fibres. Recorded nesting activity includes the rainy season, particularly from January to March, and nests generally contain two white eggs.
Identification Tips
- Look for a compact hummingbird in high páramo, especially around flowering Chuquiraga shrubs, rocky outcrops and small streams.
- An adult male is distinctive because of its brilliant blue throat, teal-green head and upperparts, white underparts and dark central belly stripe.
- Females and immature males are less immediately striking. Their green-to-bronze upperparts, dusky throat markings and scattered blue-green throat feathers are useful clues.
- Watch for unusual feeding posture. The bird often clings to flowers or branches instead of hovering continuously.
- The species has a very restricted range, so location is an important part of identification. In suitable southern Ecuadorian páramo, the combination of habitat, blue-throated male plumage and hillstar behaviour is highly distinctive.
Conservation Status
The Blue-throated Hillstar is classified as Critically Endangered, with a decreasing population estimated at approximately 80 to 110 mature individuals. The estimate is precautionary and remains subject to revision as surveys continue.
The main threats are the loss and degradation of páramo habitat, burning to create or maintain grazing land, overgrazing, replacement of native vegetation with timber plantations and potential mining activity. Off-road recreation and other disturbance may add local pressure. Climate change may intensify these threats by altering rainfall, fire conditions, vegetation and the availability of flowering plants.
Conservation measures include the creation and expansion of the Cerro de Arcos Reserve, protection of additional habitat, population monitoring, restoration of native plants and cooperation with local communities. Protecting flowering shrubs, rocky nesting sites, streams and connected páramo is essential because the species occupies such a small area.
Frequently Asked Questions
Where does the Blue-throated Hillstar live?
It lives only in a small area of high-elevation páramo in the Andes of southwestern Ecuador, particularly around the Cordillera de Chilla-Tioloma-Fierro Urco.
How rare is the Blue-throated Hillstar?
It is one of the world’s rarest hummingbirds. The current working estimate is about 80 to 110 mature individuals, and the population is considered to be declining.
What does the Blue-throated Hillstar eat?
It feeds mainly on nectar from flowering páramo plants, especially Chuquiraga jussieui. It also visits other shrubs and bromeliads and catches small insects such as flies.
How can the male be identified?
The adult male has a brilliant ultramarine-blue throat, a teal-green head and upperparts, white underparts and dark markings through the centre of the belly.
Does the Blue-throated Hillstar migrate?
It is considered non-migratory. Individuals may nevertheless move locally between flowering plants, rocky shelters and suitable habitat patches.
Where is the best place to look for this species?
Cerro de Arcos Reserve in Loja Province is the best-documented wildlife-viewing site. Visits should be arranged in advance, and observers should follow local guidance to avoid disturbing the birds or their fragile páramo habitat.
References
- Sornoza-Molina, Freile, Nilsson, Krabbe and Bonaccorso, The Auk
- American Bird Conservancy
- Fundación de Conservación Jocotoco
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