The white-tailed goldenthroat hummingbird (Polytmus guainumbi) is a small hummingbird found in tropical regions of South America. With its vibrant plumage and graceful hovering flight, this species is a delight to observe in the wild. In this article, we’ll explore the identification, range, habitat, diet, behavior, reproduction, and conservation status of the white-tailed goldenthroat.
Identification
The white-tailed goldenthroat measures just 3-4 inches (8-10 cm) in length, making it one of the smaller hummingbird species. Several key features help distinguish it from other hummingbirds. The male has a bright golden-green throat and upper breast, with a steely blue crown and nape. The undertail coverts are white, as the name suggests. The female is similar but less vibrantly colored, with greenish upperparts and whitish underparts with green streaks on the throat. Both sexes have a thin dark bill and dark legs. Juveniles resemble adult females but with buffy edges to the feathers.
The white-tailed goldenthroat is aptly named, with the golden throat being the most prominent identification marker. When observing this hummingbird, listen for its high-pitched, squeaky vocalizations. In flight, it beats its wings up to 70 times per second, allowing it to precisely hover and change direction instantly. This agile, buzzing flight is characteristic of hummingbirds.
Range and Habitat
The white-tailed goldenthroat is found from eastern Panama through northwestern South America. Its range includes Colombia, Venezuela, Ecuador, Peru, and Brazil. Within this region, it occurs in tropical forests, woodland edges, plantations, and gardens from sea level up to 5,000 feet (1,500 m) elevation.
This species prefers habitats with abundant flowering plants, where it forages for nectar and small insects. It particularly favors flowering shrubs and trees and vegetation along watercourses. Some key plants it visits include coffee, poinsettia, fuchsia, and various flowering trees and epiphytes. The white-tailed goldenthroat’s small size allows it to hover and probe deep into tubular flowers.
Diet
Like all hummingbirds, the white-tailed goldenthroat has a specialized diet consisting mainly of nectar and small insects. Its long, slender bill and extensible tongue are perfectly adapted for extracting nectar from flowers. The bill length matches the depth of the preferred flowers. Primary nectar sources include shrubs and vines in the coffee and madder families, as well as epiphytes such as bromeliads.
The white-tailed goldenthroat supplements its diet with small insects like flies, mosquitoes, spiders, and aphids. It gleans insects from foliage or catches them mid-air during flight. The extra protein gained from insects supports the high metabolisms of hummingbirds.
Behavior
The feeding, territorial, and courtship behaviors of the white-tailed goldenthroat are fascinating to observe. It has a fast, weaving flight pattern as it visits a succession of flowers, licking nectar with its specialized tongue that extends past the tip of the bill. It aggressively defends flowering patches from intruders, engaging in acrobatic chase displays with bold loop-de-loop flight patterns.
During the breeding season, males perform elaborate courtship displays to attract females. They fly in U-shaped or figure-8 patterns, with the wings whistling on the upstroke. At the top of the display, the male hovers momentarily and spreads his tail feathers to show off the iridescent white tips. Females build a small cup nest out of plant fibers,spider webs, and lichens, which is attached to a vertical twig or fern frond.
Reproduction
The white-tailed goldenthroat breeds in the rainy season, with timing varying across its range. In Central America, breeding occurs from May to August, while in South America it may nest in most months. The female lays just two tiny white eggs in her delicate cup nest, incubating them for 14 to 19 days.
The chicks hatch with eyes sealed shut and almost devoid of feathers. The female cares for and feeds the chicks with regurgitated insects and nectar. They fledge in about 20 to 26 days, gaining their full adult plumage within a few months. The housing hummingbird may raise two or three broods per season. Males do not assist with chick rearing.
Conservation Status
With its broad distribution across Central and South America, the white-tailed goldenthroat is evaluated as a species of least concern on the IUCN Red List. However, some local declines have been noted, especially in areas of severe habitat loss. Agricultural expansion, logging, and development threaten its specialized forest habitat. Climate change and pesticide use may also impact hummingbird populations.
Nonetheless, the white-tailed goldenthroat remains common across most of its range. It adapts readily to gardens and other human-modified landscapes. You can support these energetic pollinators by planting native nectar sources in your yard. Avoiding pesticide use and providing sugar water feeders also benefit hummingbirds. With appropriate habitat, the aerial antics of the white-tailed goldenthroat will continue to dazzle observers across the Neotropics.
In summary, the white-tailed goldenthroat is a delightfully petite hummingbird species adorned in shining iridescent plumage. Its specialized adaptations for hovering flight, nectar feeding, and territorial displays make it a fascinating subject for birders and scientists alike. Ensuring habitat preservation across its range is key to the continued success of this tropical pollinator. The buzzing flight and glittering colors of the white-tailed goldenthroat add sparkle and life to forests and gardens through much of South and Central America.