About Mitrospingus cassinii (Lawrence, 1861)
Mitrospingus cassinii has two subspecies that are very poorly differentiated from one another. Adult individuals of the species 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, and the face bears a large black "mask". The species' upperparts are lead gray. The throat is light gray, which transitions to olive yellow on the breast and flanks, and further transitions to a gray-olive-yellow blend on the belly. Juvenile Mitrospingus cassinii are similar to adults, but have less yellow on the crown and a buffy tinge to the underparts. The subspecies M. c. costaricensis (dusky-faced tanager) is found along the Caribbean coast, ranging from Heredia Province in Costa Rica south to extreme northwestern Panama. The nominate subspecies is found on both slopes of western Panama, extending south through western Colombia to Guayas Province in Ecuador; it also occurs on the east slope of Colombia's Central Andes. Dusky-faced tanagers inhabit low dense shrubbery, thickets, and second growth. They can also be found along forest edges, within forest gaps, alongside forest streams, and in swampy areas. In Costa Rica, the species generally occurs up to 300 m (980 ft) in elevation, but can be found as high as 600 m (2,000 ft). Its upper elevation limit is 1,200 m (3,900 ft) in Panama. In Colombia, it occurs 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).
