Chestnut-breasted Coronet is the representative of the genus Boissonneaua on the east slope of the Andes, where it occurs from southeastern Colombia south to southern Peru; it also is found on the west slope of the Andes in southwestern Ecuador and northwestern Peru. Like other species of coronet, this is a stout, heavy-bodied hummingbird with a relatively short bill (or, the bill is short compared to the bills of similarly-sized Andean hummingbirds, such as the incas and star-frontlets, Coeligena). Chestnut-breasted Coronet forages in the subcanopy and canopy of humid montane forest. Chestnut-breasted Coronet easily is recognized by the conspicuous rufous underparts and tail, and by its characteristic habit of holding the wings upright over the back for a second or two after alighting on a new perch. Although this species rarely is numerous, it is widespread; nonetheless the natural history of Chestnut-breasted Coronet is very poorly known.