Trochilus surinamensis

The Green-tailed Goldenthroat is a small hummingbird, averaging about 9 cm in length and weighing around 4 grams. It is easily recognized by its shimmering green body and distinctive gold-tinged throat that catches sunlight with a brilliant flash. Adults exhibit a vivid green crown and nape, with a white postocular stripe that provides a striking contrast to the darker feathers. The iridescent plumage of the males is slightly more vibrant than that of the females, although both sexes are similarly colored. The tail, as its common name suggests, features green feathers with a subtle blue sheen visible in certain light conditions. Juvenile birds resemble adults but often have duller plumage, lacking the full iridescence seen in mature individuals. In flight, the Green-tailed Goldenthroat's silhouette is characterized by a rapid wing beat and a slightly forked tail, which aids in its agile maneuvers. When perched, it displays an upright posture, often on slender branches or exposed twigs near flowering plants. This species can sometimes be confused with other small hummingbirds, such as the Glittering-throated Emerald, but its unique throat and tail coloring help distinguish it.

The primary diet of the Green-tailed Goldenthroat consists of nectar from a wide variety of flowering plants, making it an important pollinator in its ecosystem. It demonstrates a preference for tubular flowers, such as those of the Heliconia and Justicia species. The hummingbird uses its specialized bill to access deep floral nectaries, while its tongue rapidly licks up the nectar. In addition to nectar, the Green-tailed Goldenthroat supplements its diet with small insects and spiders, which provide essential proteins and nutrients. This insectivorous feeding is particularly important during the breeding season when the energy demands are higher. The species typically forages alone, employing a technique of hovering in front of flowers, although it may occasionally join mixed-species feeding flocks. Feeding occurs throughout the day, with peaks in activity during early morning and late afternoon when nectar production is highest.

The Green-tailed Goldenthroat exhibits a solitary and territorial nature, especially during the breeding season. Males establish and defend feeding territories, using vocalizations and aerial displays to deter rivals. These displays involve rapid, acrobatic flights accompanied by distinctive calls to assert dominance. Courtship involves elaborate aerial chases and vocal duets, after which a successful male may mate with multiple females. Outside the breeding season, these hummingbirds may become less territorial, sometimes joining mixed-species flocks to exploit abundant food sources. They demonstrate a strong response to predators, employing evasive flight maneuvers and utilizing dense foliage for cover. The species is primarily diurnal, with peak activity occurring during the cooler hours of the morning and late afternoon. Its daily routine includes periods of intense foraging interspersed with rest on sheltered perches.

The Green-tailed Goldenthroat constructs small, cup-shaped nests using plant fibers, spider silk, and lichens, often concealed on slender branches or within dense foliage. Preferred nest locations are typically 1 to 3 meters above ground, providing protection from ground predators while maintaining proximity to feeding sites. The female solely undertakes nest building, incubation, and chick rearing. A typical clutch consists of two tiny, white eggs, which she incubates for about 14 to 17 days. Upon hatching, the altricial chicks remain in the nest for approximately 20 to 24 days, during which the female provides all nourishment. The species typically raises one to two broods per year, depending on environmental conditions and resource availability.

The vocalizations of the Green-tailed Goldenthroat include a series of high-pitched, rapid trills and whistles that serve as both territorial signals and communication between mates. Its primary song comprises a combination of sharp 'chip' notes, delivered in quick succession with an energetic rhythm. Alarm calls are more abrupt and harsh, designed to warn of potential threats. During the dawn chorus, males become particularly vocal, establishing their presence and defending territories with a flurry of sound. The hummingbird's calls can be likened to the tinkling of a distant bell, adding a melodic quality to the cacophony of the tropical forest.

• 1The Green-tailed Goldenthroat can visit up to 1,500 flowers in a single day, showcasing its vital role as a pollinator.
• 2Despite its small size, the Green-tailed Goldenthroat can fly at speeds exceeding 50 km/h, thanks to its rapid wing beats.
• 3This species' iridescent plumage appears differently depending on the angle of light, a phenomenon called structural coloration.
• 4The heart of a Green-tailed Goldenthroat can beat more than 1,200 times per minute, supporting its high-energy lifestyle.
• 5The species is known to consume over half its body weight in nectar and insects daily to meet its metabolic needs.
• 6Hummingbirds, like the Green-tailed Goldenthroat, have such keen memory they can remember every flower they've visited.
• 7The Green-tailed Goldenthroat's wings can beat up to 80 times per second, allowing for exceptional hovering ability.

The IUCN currently lists the Green-tailed Goldenthroat as a species of Least Concern, with population trends considered stable. However, habitat destruction due to deforestation and agricultural expansion poses significant threats to its long-term survival. Conservation efforts focus on preserving key habitats and promoting sustainable land-use practices. Historically, the species has demonstrated resilience, maintaining stable populations despite localized pressures. Continued monitoring and habitat protection are essential to ensure its persistence in the face of ongoing environmental change.