The slender-tailed woodstar is a species of hummingbird in tribe Mellisugini of subfamily Trochilinae, the "bee hummingbirds". It is the only species placed in the genus Microstilbon. It is found in Argentina and Bolivia.
Region
Southern Andes
Typical Environment
Occurs in the eastern Andean foothills of south-central Bolivia and northwestern Argentina. It uses dry to semi-humid montane scrub, the edges and clearings of Yungas cloud forest, and second-growth thickets. It also visits hedgerows, riparian corridors, and gardens with abundant tubular flowers. Local presence can be patchy, tracking flowering cycles.
Altitude Range
800–2800 m
Climate Zone
Highland
Ease of Keeping
Beginner friendly: 1/5
This tiny hummingbird is the sole member of the genus Microstilbon and is aptly named for the male’s very slender, elongated tail. It forages by traplining between scattered flowering shrubs and trees and is often mistaken for a large bee when zipping between blossoms. Despite its small size, it can be quite territorial around rich nectar sources.
Temperament
solitary and territorial
Flight Pattern
short rapid wingbeats with agile hovering
Social Behavior
Generally solitary outside of breeding, defending small nectar-rich patches against other hummingbirds and insects. Courtship involves rapid chases and display flights by the male. The species builds a tiny cup nest of plant fibers and spider silk on a sheltered branch.
Migratory Pattern
Resident
Song Description
Often quiet, giving thin, high-pitched tsip notes and short dry trills during foraging or aggression. Wing hum is audible at close range and can form part of display flights.
Plumage
Upperparts mostly shimmering green with a contrasting pale underside; males show a small iridescent gorget and an extremely long, narrow, forked tail. Females are paler below with warm buffy flanks, a short tail with white tips, and a subtle speckled throat.
Diet
Primarily feeds on nectar from tubular flowers such as sages and other Andean shrubs and trees. Supplements nectar with small arthropods, hawking tiny insects in flight or gleaning them from foliage for protein. Follows a trapline circuit to revisit productive blooms and may guard especially rich flower patches.
Preferred Environment
Forages along forest edges, scrubby slopes, and riparian thickets where flowering plants are scattered. Also visits gardens and secondary growth with abundant ornamental and native blossoms.
