Amethyst Woodstar

Representing one of the smallest avian species in the Neotropics, this tiny hummingbird measures between 6 and 7.5 centimeters (2.3 to 2.9 inches) in total length and weighs a mere 2.3 to 2.5 grams. It exhibits pronounced sexual dimorphism. The adult male features bronzy-green upperparts and a spectacular, iridescent amethyst-pink to purple throat patch (gorget), bordered below by a conspicuous white breast band. Its tail is deeply forked, displaying elongated, narrow outer rectrices of a dark brownish-black color. Conversely, the female possesses a whitish throat sprinkled with fine dark speckles, pale cinnamon or buffy underparts, and a much shorter, rounded tail tipped with white and rufous. Both sexes possess a straight, medium-length black bill.

Geographical distribution: This species is widely but patchily distributed across eastern South America. Its geographic range encompasses portions of Colombia, Venezuela, Ecuador, Peru, the Guianas, extensive areas of Brazil (ranging from the Amazon basin southward to Rio Grande do Sul), eastern Bolivia, Paraguay, and northeastern Argentina (primarily within the Misiones province). Its regional presence is highly dynamic, often associated with seasonal migrations.

Habitat: It primarily frequents forest edges, second-growth woodlands, shrubby savannas known as Cerrado, semi-open scrublands, agricultural plantations, and suburban gardens. It occurs from sea level up to elevations of approximately 1,500 meters (4,900 feet). It generally avoids the dark, continuous interior of primary rainforests, favoring ecotones and transitional zones where solar penetration stimulates abundant floral resources.

Feeding: Primarily nectarivorous, its diet is supplemented with essential proteins obtained from minute arthropods. It feeds on a diverse array of flowering herbs, shrubs, and trees, showing a preference for plant families such as Fabaceae, Myrtaceae, Rubiaceae, and Malvaceae. It extracts nectar using a rapid, extensile bifurcated tongue while maintaining a high-frequency hovering flight. Additionally, it captures small flying insects, such as dipterans and tiny hymenopterans, in mid-air through acrobatic aerial hawking or by gleaning them directly from foliage.

Behavior: It exhibits a distinctive flight pattern that closely resembles the flight and low buzzing hum of a large hymenopteran, such as a bumblebee, frequently holding its tail cocked upward at an angle while foraging. Due to its diminutive size, it occupies a subordinate position in the feeding hierarchy when competing with larger hummingbird species. However, males aggressively defend localized feeding territories during peak blooming periods. It engages in complex latitudinal and altitudinal migrations tied to the phenological cycles of its food plants.

Nesting: Reproductive responsibilities are undertaken exclusively by the female. She constructs a minuscule, cup-shaped nest utilizing soft plant down, seed fibers, and mosses, tightly bound together with spider silk to provide structural elasticity. The exterior of the nest is camouflaged with bits of lichen to blend seamlessly with the branches of small trees or shrubs, typically situated at heights of 2 to 5 meters above the ground. The clutch consists of two white, elliptical eggs incubated solely by the female for a period of 13 to 16 days. The altricial chicks hatch blind and naked, relying entirely on maternal care and regurgitated food for 20 to 22 days before fledging.

Conservation status: It is currently classified as Least Concern (LC) on the IUCN Red List of Threatened Species. Although its global population size has not been precisely quantified, the species remains relatively common throughout its extensive range. Localized threats include habitat loss, deforestation, and agricultural expansion; however, its ability to utilize disturbed habitats, secondary forests, and urban parks helps buffer the species against severe population declines.