Wedge-tailed Hillstar

Identifying the Wedge-tailed Hillstar involves recognizing its unique field marks. Adult males display a striking iridescent green plumage on their back and crown, while their throat shines with a vibrant blue. The most distinctive feature is their elongated tail, which is wedge-shaped, a trait that gives the bird its common name. Females, while less colorful, exhibit a more subdued green on their backs and a white underbelly with light spotting. Juveniles resemble females but with more muted colors, making them harder to distinguish at first glance. In flight, the Wedge-tailed Hillstar's silhouette is noteworthy, with its long tail often fanned out, creating a dramatic presence against the Andean skies. When perched, the bird maintains an upright posture, often showcasing its tail's unique shape. The species is sometimes confused with other hillstars, such as the White-sided Hillstar, but the latter lacks the distinctive wedge-shaped tail and has different throat coloration. Observing these details can help birders accurately identify the Wedge-tailed Hillstar in its natural habitat.

The diet of the Wedge-tailed Hillstar primarily consists of nectar from native flowering plants, such as chuquiraga and other high-altitude flora. These flowers provide a rich source of energy essential for the bird's fast-paced lifestyle. Secondary food sources include small insects and spiders, which supply necessary proteins and nutrients. Seasonal dietary changes occur as different plants bloom at varying times, prompting the hillstar to adjust its foraging behavior accordingly. The bird employs a hovering flight technique to feed, using its specialized tongue to extract nectar while maintaining balance in windy, high-altitude conditions. Typically, the hillstar feeds throughout the day, with peak activity observed during early morning and late afternoon when nectar production is at its highest.

The Wedge-tailed Hillstar exhibits intriguing behaviors that reflect its adaptation to the Andean environment. It is generally solitary outside of the breeding season, with individuals maintaining territories around rich nectar sources. Territorial behavior involves aggressive displays and vocalizations to ward off intruding hillstars and other hummingbirds. During courtship, males perform aerial displays, characterized by rapid dives and sharp, loud calls to attract females. Once a mate is secured, the bond is brief, and the male does not participate in nest building or chick rearing. The hillstar is diurnal, with its activity patterns closely tied to the availability of food and environmental conditions. In response to predators such as hawks and falcons, the bird relies on its agile flight to evade capture, often taking refuge in dense vegetation or rocky crevices.

Nesting for the Wedge-tailed Hillstar involves careful construction and strategic placement. The female builds a cup-shaped nest using plant fibers, moss, and lichens, often camouflaged against rock faces or under overhangs to protect from the elements and predators. Nests are typically situated at elevations that offer both safety and proximity to food sources. Clutch sizes usually consist of two eggs, with the female solely responsible for incubation, which lasts about 16 to 18 days. Following hatching, the chicks remain in the nest for approximately three weeks before fledging. The female provides all parental care, feeding the young with regurgitated nectar and insects. Typically, the Wedge-tailed Hillstar raises one brood per breeding season, although favorable conditions may allow for a second.

The Wedge-tailed Hillstar's primary song consists of a series of high-pitched, thin notes delivered in rapid succession, creating a melodious yet somewhat metallic quality. These vocalizations serve as territorial markers and play a role in courtship displays. Call notes are sharp and abrupt, used in aggressive encounters or as alarms to signal danger. During the dawn chorus, the hillstar's song blends with the calls of other Andean birds, creating a vibrant acoustic landscape. Compared to other hummingbirds, its vocalizations are distinctive, aiding identification in the field.

• 1The Wedge-tailed Hillstar can hover in place like a helicopter, allowing it to feed from flowers without landing.
• 2Despite its small size, the Wedge-tailed Hillstar's heart can beat over 1,200 times per minute during flight.
• 3The species' name 'hillstar' reflects its affinity for mountainous regions and its star-like appearance in flight.
• 4Wedge-tailed Hillstars can enter torpor, a hibernation-like state, to conserve energy during cold nights.
• 5The bird's unique tail shape not only aids in identification but also enhances its maneuverability in flight.
• 6Each individual hillstar has a unique iridescent throat patch, which reflects light differently at various angles.
• 7The Wedge-tailed Hillstar contributes to pollination by transferring pollen on its head and bill as it feeds.

Currently, the Wedge-tailed Hillstar is classified as Least Concern by the IUCN, with a stable population trend. However, ongoing threats include habitat degradation due to agricultural expansion and climate change, which could alter its high-altitude habitat. Conservation efforts focus on preserving the páramo ecosystem, ensuring that this unique habitat remains intact. Historical population changes have shown resilience, but continuous monitoring is essential to detect any future declines. Local initiatives aim to promote sustainable land use practices that benefit both the hillstar and the indigenous communities.