The scarlet tanager is a medium-sized songbird. It measures between 6.3 and 6.7 inches (16 to 17 cm) in length and its wingspan is between 9.8 and 11.4 inches (24.8 to 29 cm). The most distinctive feature of the males of this species is their bright red color. Breeding males have a black tail and wings while the rest of their body is bright red. They possess a whitish bill, dark eyes and gray legs. Unlike their name would suggest, not all scarlet tanagers are red in color. Non-breeding males also have a black tail and wings, however, their body is bright olive-green. During molts in spring and fall, they show mixed red and olive green in body feathers. Females, on the other hand present an olive green to yellow body, with the brightest parts being the throat, rump, and undertail. Their tail is edged green, while their wings are brownish olive. Young scarlet tanagers resemble adult females. This species’ song corresponds to a series of short, burry syllables, resembling the song of a robin with a sore throat. Their call is a springy “chik-burr”.
The scarlet tanager is a Neotropical migrant. It spends the breeding season in eastern North America, in deciduous and mixed deciduous-coniferous woodlands and mature forests. It is occasionally found in suburban areas with large trees. Scarlet tanagers spend winters in montane evergreen forests in northern and western South America, from Panama to Bolivia. Males usually arrive from their winter habitats slightly before the females to claim a territory among the tall trees.
Their diet is composed of insects (including ants, dragonflies, termites, caterpillars, gypsy moths, and parasitic wasps), spiders, some earthworms, buds, and fruit. Scarlet tanagers capture insects while hovering and can also capture flying insects in midair.
Scarlet tanagers spend most of their time in the canopy foraging for food and are thus often missed despite their bright color. Predators include birds of prey, including owls and merlins. Their eggs and nestlings are vulnerable to blue jays, grackles, American crows, squirrels, chipmunks, and snakes. As a form of protection, scarlet tanagers mob most predators that come near them, diving and swooping while calling at them. The biggest threat to their populations comes from habitat fragmentation in several parts of its range, often due to road construction or land clearing for human expansion.