The dusky-faced tanager (Mitrospingus cassinii ) is a species of bird in the family Mitrospingidae. It is found in Colombia, Costa Rica, Ecuador, and Panama.
The two subspecies are "very poorly differentiated." The adults are 18 to 18.5 cm (7.1 to 7.3 in) long and weigh 32 to 39 g (1.1 to 1.4 oz). Their crown and nape are mustard yellow. The face has a large black "mask". Their upper parts are lead gray. The throat is light gray transitioning to olive yellow on the breast and flanks and further to a gray-olive-yellow blend on the belly. The juvenile is similar but has less yellow on the crown and a buffy tinge to the underparts.
The dusky-faced tanager of subspecies M. c. costaricensis is found along the Caribbean coast from Costa Rica's Heredia Province south to extreme northwestern Panama. The nominate is found on both slopes of western Panama south through western Colombia to Guayas Province in Ecuador. It also occurs on the east slope of Colombia's Central Andes.
The dusky-face tanager inhabits low dense shrubbery, thickets, and second growth. It is found along forest edges, gaps in forest, and along forest streams and swampy areas. In Costa Rica it generally ranges up to 300 m (980 ft) but can be found up to 600 m (2,000 ft). Its upper limit in Panama is 1,200 m (3,900 ft). In Colombia it is mostly below 800 m (2,600 ft) though it has been recorded up to 1,100 m (3,600 ft). In Ecuador it can be found as high as 800 m (2,600 ft).
The dusky-faced tanager appears to primarily eat fruits, though it also eats insects and seeds.
The dusky-faced tanager's breeding phenology has not been thoroughly studied. Breeding or breeding-condition birds have been recorded between March and May from Costa Rica, Panama, and Colombia. Two well-described nests were cups suspended in shrubs. The apparent clutch size is two, and nestlings were attended by at least three adults.
