Setophaga ruticilla

The American Redstarts are easily distinguished from other wood-warblers breeding in North America by their combination of black plumage with contrasting bright wing and tail patches, orange in adult males and yellow in female, immatures and second-year males. These striking, sexually dimorphic plumages are useful in enabling redstarts to identify potential mates visually. These warblers also use the plumages in foraging for their small insect prey in the foliage of deciduous trees and shrubs. Moving around through leaves and small twigs, they flutter their wings and tail, “flashing” the brightly colored patches to startle hidden prey into flight where the redstarts catch them. The combination of leaf- and twig-gleaning with aerial capture makes their foraging more efficient, as well as making these warblers easier for birdwatchers to observe. (Sherry and Holmes 1997).

The declining status of American Redstarts in Texas is not surprising since this state is at the southwest corner of the redstart’s eastern breeding range where habitat and climate changes are often first apparent. The situation is similar to that in some western states where small populations of American Redstarts are decreasing or have disappeared. In Arizona, atlasers were unable to find any breeding evidence where breeding had formerly occurred (Corman 2005). In Colorado this redstart is still a rare summer resident with breeding found at 14 scattered locations spread through 4 latilong blocks following the east slope of the Rocky Mountains and 2 latilong blocks on the north border of the state. Most (13) of these locations were in riparian habitats (Baker 1998).

DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, researchers found a single confirmed breeding record in latilong-quad 31093-D7; 4 probable records in 30094-F6, 30097-F5, 31094-C1 and 33094-E4 and 15 possible records. As the map below indicates these records are in east Texas, mostly in the Pineywoods region along the Louisiana border.

Elsewhere American Redstarts breed most commonly from British Columbia east through southern Canada and the northern Great Lakes States to the Maritime Provinces and New England. The range continues south in the Appalachian Mountains to Tennessee with an additional population in Alabama. Breeding also occurs spottily in other states (Sauer et al. 2005). The species winters in Middle America and northern South America and throughout the Caribbean islands (Howell and Webb 1995, Sherry and Holmes 1997).

SEASONAL OCCURRENCE. Migrating American Redstarts are uncommon to locally common in the eastern half of Texas primarily from mid-April to early June and mid-August to mid-October. Breeding, based on old records, includes June (Oberholser 1974, Lockwood and Freeman 2004). June is peak month for eggs in nests across the total breeding range; with earliest egg dates in late May and latest dates for young in nests recorded in late July (Sherry and Holmes 1997).

BREEDING HABITAT. Across their breeding range American Redstarts prefer moist, deciduous, second-growth woodlands with abundant shrubs. In southern and western parts of the redstart’s range these habitats are often found near lakes, streams or swamps (Sherry and Holmes 1997).

The female selects a site usually next to the trunk of a tree or in a crotch of a bush with several more-or-less vertical stems. The female fits a tightly woven open cup into the site, using a variety of natural materials, including bark strips, grasses, plant down and fibers, hair, feathers, leaves, rootlets, lichens, twigs and moss often reinforced with spider silk. The structure which may be built in as little as 2.5 days or as long as >1 week, is lined with fine materials including hair and feathers. The outside diameter is about 6.7-7 cm (2.7-2.8 in), height 6.3-7.6 cm (2.5-3 in), inside diameter 4.5 cm (1.8 in) and the cup depth is 3.2-3.8 cm (1.3-1.5 in). The nest is similar to that of Yellow Warbler (Dendroica petechia), but is neater and has thinner walls.

In this cup female redstarts usually lay 4 (range 1-5) white eggs, speckled or blotched with red to brown, often in a wreath at the large end.. The female incubates the eggs for 10-13 days and the young birds leave the nest about 9 days after hatching. At least in the northern part of the redstart’s range, there is only one brood. Rates of parasitism by Brown-headed Cowbirds (Molothrus ater) vary from 0 to at least 70% depending on location (Harrison 1979, Sherry and Holmes 1997)

STATUS. American Redstarts are rare to uncommon and very local summer residents in forests of extreme east Texas (Lockwood and Freeman 2004). The map in Oberholser (1974) shows summer and breeding records in northeast Texas and scattered across the state south of the 32nd parallel. The differences between this and the TBBA map suggest a significant summer range reduction in the last 150 years. Oberholser (1974) quotes an 1888 report describing this redstart as “common” in Bowie County in summer, clearly different from the current status (Lockwood and Freeman 2004). The North American Breeding Bird Survey does not sample American Redstart in Texas but data from across its breeding range provides a 1980-2005 population trend of 0.8% population change per year (Sauer et al. 2005). In Oklahoma a decline has occurred and only 3 possible breeding records were found during their atlas work (Bay 2004). The future of American Redstart as a breeding species in Texas does not seem hopeful.  Text by Robert C. Tweit (2007)