The breeding male scarlet tanager is one of the easier North American birds to identify. Often seen in small flocks during migration, the scarlet sings on the breeding grounds and feeds high in the canopy. It moves sluggishly and can be difficult to spot. Monotypic. Length 7".

Sexually dimorphic. Both sexes have whitish wing lining. Breeding male: unmistakable, brilliant red all over, with black wings and tail. The bill, somewhat short and stubby, is thick at the base. Breeding female: females are entirely yellow-green, with yellower throat and sides, dark wings and tail, a thin eye ring, and wing coverts with greenish edging. Some adult females show weak wing bars. Winter adult: entirely greenish ­yellow, but retains black scapulars, wings, and tail.