The Bahama Woodstar is a hummingbird found in the Bahamas that comprises two subspecies. One of these, Calliphlox evelynae evelynae, is found throughout the islands, especially in the northern Bahamas. The other, Calliphlox evelynae lyrura, is found only among the southern Inaguan Islands of the archipelago. The name “lyrura” for lyre-tailed, refers to the male’s forked tail, which resembles a classical lyre harp.
A research team including biologist Christopher J. Clark of the University of California, Riverside, argues in a paper published in the January issue of The Auk that the two subspecies should be recognized as distinct species.
“The two subspecies were originally described as separate species, partly on the basis of small differences in the tail feathers between them, but were then classified in 1945 as subspecies of the Bahama Woodstar,” explained Clark, an assistant professor of biology. “It’s time now to call these two distinct species of hummingbirds.”
Both C.e. evelynae and C.e. lyrura produce mechanical sounds with their tails during courtship displays. The researchers recorded the pops and whistles produced when air runs along male tail feathers during mating display dives.
They also collected field recordings of scolding calls and songs of the two subspecies. They compared beak and wing lengths. Using tissue samples, they investigated the degree to which populations of evelynae and lyrura diverged in genetics.
They found that:
- The tail of the adult male lyrura is more strongly forked than that of evelynae
- The sounds produced by lyrura tail feathers were significantly higher pitched than those of evelynae, as a result of different feather shapes
- Scolding calls qualitatively differed between lyrura and evelynae
- Male lyrura have a distinctly different song than male evelynae; male evelynae produced rambling songs while songs of the male lyrura sounded like wet squeaky shoes
- evelynae and lyrura populations diverged genetically sometime between about 400,000 years ago and about 1 million years ago
“Our findings suggest that lyrura is best considered a full species,” Clark said.
In a petition to the classification committee of the American Ornithologists’ Union (see page 36 of this PDF), Clark suggests keeping the name Bahama Woodstar as the common name of the northern evelynae population. For lyrura, he recommends Inagua Sheartail but says the species also could be named Inagua Lyretail, Inagua Hummingbird, or Lyre-tailed Hummingbird.
The committee is expected to announce its decision on this and other proposals in summer 2015.
Read the paper
Teresa J. Feo, Jacob M. Musser, Jacob Berv, and Christopher James Clark (2015). Divergence in morphology, calls, song, mechanical sounds, and genetics supports species status for the Inaguan hummingbird (Trochilidae: Calliphlox “evelynae” lyrura). The Auk 132, Issue 1. Full text.