White-eared Hummingbird is a medium sized hummingbirda with a straight bill that is bright red, with a black tip, and is broad at the base. The sexes are similar in pattern, but females are duller in color. The most distinctive feature of this species is the head pattern: the sides of the head are blackish, and bordered above by a bold white stripe (the white "ears"). The upperparts generally are coppery green, becoming more cinnamon rufous on the rump. The tail is of medium length and blunt tipped or with a slight central notch. The male has a bluish violet forecrown and chin, and a glittering green throat. The underparts are whitish, heavily speckled with green. The female lacks the violet forecrown and chin, and throat of the female is white, speckled with green.
White-eared Hummingbird has a distinctive facial pattern, and usually is unlikely to be confused with any other species. Some care must be taken, however, to distinguish females and immatures of White-eared from comparable plumages of Broad-billed Hummingbird (Cynanthus latirostris). Broad-billed Hummingbird is slimmer than White-eared, with a longer bill, a less prominent postocular streak and paler (less blackish) sides to the head, and the underparts (especially on the throat) are less heavily speckled with green. Calls also differ between the two species: the chatter call of Broad-billed is buzzier and less metallic than the corresponding call of White-eared.
The following description is based on Ridgway (1911) and Williamson (2001), and refers to nominate leucotis; see also Geographic Variation:
Adult male: Forecrown, loral region, malars, chin, and upper throat rich metallic violet or bluish violet, becoming velvety black on the suborbital and auricular regions, and duller black on the crown. Broad white postocular stripe, extending backwards and downwards above and behind the auriculars, reaching the sides of the neck. Upperparts generally bright metallic green to bronze green, the uppertail coverts more bronzy, and the feathers of the rump and uppertail coverts margined with rusty or cinnamon rufous. Central pair of rectrices bright bronze green; adjacent pair darker, and the outer pairs of rectrices bronzy black, tipped with bright bronze or bronze green. Remiges purplish dusky, the inner secondaries glossed with bronze green. Lower throat brilliant metallic emerald green, sharply defined against the dark violet blue of the upper throat and chin. Breast and flanks bronze or bronze green, feathers with grayish margins. Center of breast and belly dull grayish white. Tibial tufts dull white. Undertail coverts grayish brown, faintly glossed with bronze, and centrally margined with dull whitish.
Adult female: Upperparts similar to adult male, but crown dusky brown, the feathers (especially on the forecrown) sometimes margined with pale rusty brown. Lateral pair of rectrices broadly tipped with brownish gray. Face pattern similar to that of male. Underparts pale brownish gray or dull grayish white, spotted with metallic bronze green, the spotting more prominent on the sides. Undertail coverts centrally grayish, broadly margined with dull grayish white.
Immature male: Similar to adult female, but has an irregular patch of metallic green feathers on the throat, and the pale tips of the outer rectrices are smaller and less distinct.
Second year male: Similar to the adult male, but the violet blue of the forecrown and chin is reduced or absent.
Immature female: Very similar to adult female. Upperparts slightly duller, the feathers with broad, dull cinnamon ;to tawny edges; a buffy wash on the underparts; and more extensive pale tips on the outer rectrices.
The preformative molt (July-February) is complete, as is the definitive prebasic molt (June-January) (Pyle 1997). In northern migratory populations, the prebasic molt commences on the breeding ground, but may be completed on the wintering grounds (Pyle 1997). Wagner (1957) suggested that the timing of molt in Mexico may differ between the sexes, with molt in males more prevalent August-November, but is earlier (March-May) in females (although it is possible that Wagner's data includes more than one age class/sex?).
Iris: dark brown
Bill: adult male, bright coral red with black tip; adult female, maxilla blackish with some coral red or orangish basally, mandible orange or red with a black tip; immature male, maxilla may be mostly blackish, or with red, sometimes extensive, at the base
Tarsi and toes: dark brown, dusky
Bare parts color data from Dickey and van Rossem (1938), Johnsgard (1997), and Williamson (2001).
Total length: 9-10 cm (Howell and Webb 1995, Williamson 2001)
Linear measurements (from Ridgway 1911):
male (leucotis, n = 17)
wing length: mean 55.3 mm (range 52.5-59.5 mm)
tail length: mean 33 mm (range 30.5-45.5 mm)
bill length: mean 16.6 mm (range 14.5-18.5 mm)
female (leucotis, n = 15)
wing length: 51.9 mm (range 49-55 mm)
tail length: 31.3 mm (range 30-33.5 mm)
bill length: 17.4 mm (range 16-18.5 mm)
male, mean 3.6 ± 0.3 g (n = 158; Dunning 1984)
female, mean 3.2 ± 0.2 g (n = 51; Dunning 1984)