The Blue-winged Mountain-Tanager is a common, widespread tanager of lower Andean cloud forests. Large and brilliantly patterned in yellow, black, and blue, this species is conspicuous and unmistakable. It is almost always found in groups of 3 to 10 birds that move quickly through the forest, and it may be one of the "nuclear species" around which mixed-species feeding flocks form. Ranging from northern Venezuela south through northwestern Bolivia, this species shows a fair amount of geographic variation across its range. Among the more distinctive subspecies are the following: in eastern Colombia and northeastern Ecuador birds have green backs (subspecies baezae); in southwestern Colombia and western Ecuador, birds have blue edgings in the flight feathers (subspecies cyanoptera); and in populations in Bolivia and southeastern Peru, the rump is bright blue (subspecies flavinucha).