American Redstart, Setophaga ruticilla

American Redstart, Setophaga ruticilla, Female or Immature Male. Photograph taken within a residential community in Hereford, Arizona, September 2020. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

Background and Identification

The American Redstart is a small wood warbler known for its striking plumage and lively behavior. It is a favorite among birdwatchers. Both sexes display a distinctive tail-flicking behavior, which helps flush out insects from foliage. Behavioral and evolutionary biologists have studied American Redstarts for multiple decades attempting to determine why the plumage of first-year males resembles that of the females. This could be an evolutionary adaptation to keep first-year males from looking desirable to females and siring offspring. In Mexico, the American Redstart is called Redstart Americana.

American Redstarts exhibit sexual dimorphism, although male and female individuals fall within the same size and weight ranges. Mature individuals, both male and female, are about 11–13 cm long and 6–9 g in mass. Adult males are easily identifiable by their black and bright orange coloring. They have black upperparts with vivid orange patches on their wings, sides, and tail. This makes adult males easily distinguishable from all other species. Females and immature males have gray-olive upperparts with yellow patches instead of orange.

Habitat and Geographical Range

The American Redstart occupies a wide variety of habitats in all seasons. They are a highly migratory species. These include open wooded habitats, secondary forests, fencerows, and deciduous woodlands in the summer. In its winter range, it is found in low to mid-elevations in tropical and subtropical habitats where woods and dense trees are present. They can be found in primary and secondary forests, coffee and citrus plantations, and even isolated trees in residential urban areas. They also inhabit mangrove forests, specifically black mangroves, scientifically known as Avicennia. 

The American Redstart has a large geographical range. Year-round, they inhabit most of North and Central America. During the breeding season, which spans from May to August, they are primarily found in Eastern North America, extending from southern Canada to the United States. In the Winter, Redstarts migrate to Central America, the Caribbean, and the northern parts of South America. Here they occupy tropical forests, mangroves, and shrubs.

Common Misidentifications

The American Redstart’s bright coloration and active foraging behavior make it relatively distinctive, but it can still be confused with other species. Female American Redstarts, with their more subdued yellow markings, can be mistaken for other female warblers such as the Yellow Warbler, Steophaga petechia. The Redstart’s tail-flicking behavior and the pattern of its wing and tail patches help distinguish them.

Conservation Status

From a conservation perspective, the American Redstart is currently considered of Least Concern with stable, widely distributed populations.