None in general English use; Chupamirto morada chico, Tijereta Oaxaqueña (Spanish).
Endemic resident of Mexico from central Guerrero and southern Puebla east to eastern Oaxaca.
None recognized.
Wing, males 35–39 mm (ave. of 8, 36.7 mm), females 36.5–40.5 mm (ave. of 3, 38.5 mm). Exposed culmen, males 17–18.5 mm (ave. of 8, 17.9 mm), females 18.5–19 mm (ave. of 3, 18.7 mm) (Ridgway, 1911). Eggs, 12.4 × 8.2–8.3 mm (Rowley, 1984).
Three birds of unspecified sex had a mean mass of 2.9 g (Brown and Bowers, 1985).
Adult male. Upperparts metallic bronze to bronze-green, this color extending to the four middle rectrices, which are much shorter than the outer three pairs; the rest of the rectrices plain purplish bronzy black, the second from the outermost the longest, and the outermost with rounded rather than pointed tips (compare lucifer hummingbird); a small white postocular stripe, above a gorget of metallic magenta-purple feathers; Gorget bounded below by a white throat, the white extending down the median portion of the breast to the under tail-coverts; Sides and flanks metallic bronze or bronze-green, with some cinnamon-rufous on the flanks; iris brown; feet and bill black.
Residential ranges of the sparkling-tailed hummingbird (inked), beautiful hummingbird (hatched), and Mexican sheartail (cross-hatching, plus an arrowhead showing an extralimital breeding location). (Adapted from Howell and Webb, 1995)
Adult female. Upperparts similar to the male, but somewhat duller throughout, especially on the forehead, and without a metallic gorget; tail shorter and double-rounded rather than forked in profile, with the middle pair of rectrices bronze-green, the second pair blackish near the tips, and the three lateral pairs cinnamon-rufous basally and with subterminal black bands and white spots or tips; underparts including the throat dull grayish buffy, which becomes more cinnamon-toned on the flanks.
Immature male. Initially similar to the female, but gradually developing a forked tail and a metallic gorget. Young birds of both sexes probably have parallel striations on the upper mandible.
In the hand. Adults of both sexes differ mainly from the lucifer in their slightly shorter bills (17–19 mm, vs. 19–22 mm), which are less decurved. Males have outermost rectrices that are round-tipped and nearly as wide as the adjacent pair, rather than pointed and much narrower. Females have shorter wings (35–39 mm, vs. 39–44 mm), and shorter middle rectrices (12–16.5 mm vs. 16–21 mm) than is the case with the lucifer.
In the field. This tiny hummingbird closely resembles the lucifer hummingbird and is only incompletely geographically separated from it. These two species can be safely distinguished only in the hand: Both species are unique in their long, slightly decurved bills and (in adult males) their magenta-red iridescent gorgets and somewhat forked tails. Females of the two species are even more similar than males, but as with the male the female’s bill of this species is somewhat shorter and is only very slightly decurved. Vocalizations include the usual high-pitched chirps of hummingbirds, and thin and high-pitched squeaky notes that are produced during aerial courtship display.
This species is associated with arid brush, thorn forest, and scrubby open habitats with scattered trees or elevated perches, from about 1000 to 2000 meters’ elevation (Howell and Webb, 1995). In Oaxaca the species is an uncommon permanent resident in arid subtropical scrub, at elevations of about 1000 to 2200 meters (Binford, 1989).
No migrations or local movements have been documented.
No specific information is available, but the ecology of this species is unlikely to differ substantially from that of the lucifer hummingbird.
Rowley (1984) found a nest with two eggs during early May, in a garden in the city of Oaxaca. At the time of the nest’s discovery, the female was sitting on two fresh eggs. The nest was situated approximately 2.5 meters above ground, and it was attached to the forking branch of a Bougainvillea vine. The lining was composed of very small plant down, perhaps from a milkweed, and the outside was covered by brown composite pappi. Incubation intervals by the female lasted 2 to 15 minutes.
This species is a very close allopatric relative of the lucifer hummingbird, scarcely separable from it at the species level.