The American redstart is a small warbler, measuring 4.3 to 5.1 inches (11 to 13 cm) in length with an average wingspan of 6.3 to 7.5 inches (16 to 19 cm). Adult males are black with orange patches on the sides of the chest and across the wings and tail. Females have a light gray head, a gray to light green back and yellow patches on the sides of their breast and in the wings. They have a faint, broken white eye-ring and black legs. Young birds are similar in appearance to the adult females, except for a darker tail and irregular patches of black on the head, breast or back. The American redstart song is a series of high notes, some with an accented ending note: “Wee-see, wee-see, wee-see”. The most characteristic call is “tsee, tsee, tsee, tsee, tsway”. During courtship, the male shows the females a variety of potential nest sites. The female selects the final location and builds the nest, usually against a tree trunk.
American redstarts inhabit moist deciduous forests with abundant shrubs. They are Neotropical migrant birds, spending the summer in the central and eastern United states and Canada, and wintering in Central America and the northern part of South America. In addition to natural forests, American redstarts inhabit shade-grown coffee plantations during the winter.
This species feeds mostly on insects and some small fruit. American redstarts move rapidly through the forest foraging for prey, flashing their wings and tail to flush the insect prey from the foliage.
While the American redstart is widespread and abundant, declines in the population have been noted in many areas. The main threats they face are from habitat loss of both their breeding and wintering grounds. Forest fragmentation creates more edges, which leaves American redstarts vulnerable to predation by cowbirds that lay their eggs inside the nests of other bird species. Other predators of this species include accipitrine hawks and condors.