About Vireo brevipennis (P.L.Sclater, 1858)
The slaty vireo (Vireo brevipennis) is 11.5 to 12 cm (4.5 to 4.7 in) long. One individual weighed 11.8 g (0.42 oz), and two other individuals weighed 12.3 g (0.43 oz). Few other vireos have as striking a plumage as the slaty vireo, and its appearance is unique within its range. The sexes share identical plumage.
Adults of the nominate subspecies have an olive green crown, and blackish lores on an otherwise slate gray face. Their upperparts are slate, with an olive green tinge on the rump and uppertail coverts. Their wing coverts are olive green. The flight feathers of the wing and tail feathers are dull black or blackish slate, with wide olive green edges on their outer webs. Their chin is white, their throat, breast, and flanks are slate gray, and their belly and undertail coverts are white.
Juveniles have an olive head and upperparts, two buffy lemon wing bars, and whitish underparts with dusky sides on the breast. Subspecies V. b. browni has an olive green tinge from its lower back to its uppertail coverts, and paler gray underparts than the nominate subspecies. Both subspecies have a white iris, a black bill, and dark gray or dusky legs and feet.
The slaty vireo is found inland in southwestern Mexico, ranging from southern Jalisco south to central Oaxaca, and extends somewhat east into western Veracruz. It inhabits scrublands (often those with oaks), the understory and edges of pine-oak forest, and thickets. It occurs at elevations between 1,200 and 3,000 m (3,900 and 9,800 ft).
