Swallow-tailed Hummingbird

Identification

The swallow-tailed hummingbird is a relatively large hummingbird, measuring 15–17 cm in length with nearly half of this comprising its distinctive long, deeply forked tail that gives the species its common name. Weighing up to 9 g, it is among the largest typical hummingbirds across much of its range. The plumage is brilliant iridescent green with a striking blue head, upper chest, tail, and vent. The remiges are blackish-brown, and the bird features well-developed white ankle tufts and a slightly decurved medium-long black bill. Females are approximately one-fourth smaller and slightly duller than males, while immature birds resemble females but display particularly dull, brownish-tinged heads.

This species is virtually unmistakable in the field, though occasionally confused with the male violet-capped woodnymph, which has only a blue cap with the remainder of the head green like the belly. The swallow-tailed hummingbird's blue coloring extends across the entire head and upper body. Subspecies vary mainly in plumage hue, with blues ranging from green-tinged to deep royal blue and greens from golden bronze to blue-tinged. The bird's voice includes relatively loud psek notes, weaker twitters, and an excited tik call.