Systematics

Two subspecies recognized:

ellioti, described as Atthis ellioti Ridgway 1878; type locality Volcán de Fuego, Guatemala

Occurs in the highlands of southern Mexico (south of the Isthmus of Tehuantepec) and Guatemala.

See Detailed Description.

selasphoroides, described as Atthis heloisa selasphoroides Griscom 1932; type locality Cerro Cantoral, Honduras

Occurs in the highlands of El Salvador and Honduras.

"Very slightly smaller than [nominate] heloisa; resembling ellioti Ridgway of Guatemala in having a normal outer primary and grayish brown auriculars; differing from all forms of heloisa in having buff, instead of white, tail tips, the black subterminal area more extensive and the median pair of tail-feathers always tipped with dusky in both sexes; both sexes also much more buff, less white, below, especially on the under tail-coverts; adult male differing further in lacking any bluish or purplish reflections on the gorget, and in a certain position of light in having the gorget ... a much more pronounced bottle-green" (Griscom 1932: 59).

Atthis ellioti is closely related to Atthis heloisa (Bumblebee Hummingbird), which replaces ellioti north of the Isthmus of Tehuantepec. These have been considered as conspecific (under the species name heloisa) by many authors (e.g. Ridgway 1911, Peters 1945).

Some authors place both species of Atthis in the genus Selasphorus (e.g. Howell and Webb 1995).

A recent phylogenetic survey of the phylogenetic relationships of hummingbirds, based on DNA sequence data from both mitochondrial and nuclear genes, did not include representatives of Atthis (McGuire et al. 2007, 2009). This survey reveals that hummingbirds (Trochilidae) constitute nine major clades, comprising the hermits, mangos, Patagona, topazes, coquettes, brilliants, mountain-gems, bees, and emeralds (McGuire et al. 2007, 2009). Atthis is presumed to belong to the bee clade; other genera confirmed as belonging to this clade are Archilochus, Calliphlox, Calypte, Chaetocercus, Myrtis, Rhodopis, and Selasphorus (McGuire et al. 2007), and additional genera that are assumed to belong to this clade, besides Atthis, are Calothorax, Doricha, Eulidia, Mellisuga, Microstilbon, Myrmia, Tilmatura, and Thaumastura (McGuire et al. 2009).