[3] The scarlet tanager, a mid-sized passerine, is marginally the smallest of the four species of Piranga that breed north of the Mexican border.

The somewhat confusing specific epithet olivacea ("the olive-colored one") was based on a female or immature specimen rather than erythromelas ("the red-and-black one"), which authors attempted to ascribe to the species throughout the 19th century (older scientific names always takes precedence, however).

They can occur, with varying degrees of success, in young successional woodlands and occasionally in extensive plantings of shade trees in suburban areas, parks, and cemeteries.

Scarlet tanagers are often out of sight, foraging high in trees, sometimes flying out to catch insects in flight and then returning to the same general perch, in a hunting style known as "sallying".

Any flying variety of insect can readily be taken when common, such as bees, wasps, hornets, ants, and sawflies; moths and butterflies; beetles; flies; cicadas, leafhoppers, spittlebugs, treehoppers, plant lice, and scale insects; termites; grasshoppers and locusts; dragonflies; and dobsonflies.

[13] Plant components of their diet include a wide variety of fruits that are eaten mainly when insect population are low: blackberries (Rubus allegheniensis), raspberries (R. ideaus), huckleberries (Gaylussacia sp.

[16] In western New York, fledgling success increased from 22% in scattered patches of woods to as high as 64% in extensive, undisturbed hardwood forest.

[7] Exposure and starvation can occasionally kill scarlet tanagers, especially when exceptionally cold or wet weather hits eastern North America.

[18] Recorded nest predators are primarily avian like blue jays (Cyanocitta cristata), common grackles (Quiscalus quiscula) and American crows (Corvus brachyrhynchos), although others such as squirrels, chipmunks, raccoons (Procyon lotor), domestic cats (Felis catus), and snakes take a heavy toll.

[5][19][20] Scarlet tanagers birds do best in the forest interior, where they are less exposed to predators and brood parasitism by the brown-headed cowbird.

Specifically, their numbers are declining in some areas due to habitat fragmentation, but the IUCN still classifies the scarlet tanager as being of least concern.