A small, lively wood-warbler (Parulidae), the American Redstart is unforgettable for its conspicuous pirouettes, acrobatic fly-catching sorties, and conspicuous orange-on-black plumage in adult males—yellow-on-gray in females and first-year males. The brightly colored “flash patterns,” which the redstart displays while fanning its tail and drooping its wings, appear to flush prey from vegetation but also serve in communication among individuals of various ages and sexes. The flattened bill with well-developed rictal bristles and proportionately large wing and tail area facilitate in-flight pursuit of insect prey, a behavior used more often than phylogenetically related parulids. This warbler is also vocally conspicuous, especially during the breeding season, with its series of high-pitched phrases sung in a variety of song types and patterns. The fact that the plumage of first-year males resembles that of the female has elicited considerable interest among behavioral and evolutionary biologists.

Corresponding with its broad geographic range (Figure 1), this species occupies a wide variety of open wooded habitats in summer, including secondary forests, fencerows, and deciduous woodlands. Within its overwintering range it is found in virtually any low- to mid-elevation tropical or subtropical habitat with woods or trees, including mangroves (especially black mangroves, Avicennia), primary forest, secondary forest, coffee and citrus plantations, and even isolated trees in residential urban areas.

American Redstarts are locally abundant in much of their breeding range, particularly where appropriate habitat remains. Based on Breeding Bird Survey data (1966–2013), populations have declined in particular habitats (especially in some fragmented and urbanized landscapes) and regions while increasing in others, with only a slight decline in survey-wide abundance ( Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxtent Wildlife Research Center 2014b. Available from http://www.mbr-pwrc.usgs.gov/bbs/. Close Sauer et al. 2014b).

Its broad geographic range and abundance, conspicuous foraging and communication behaviors, and accessibly low nests, coupled with concern about declining populations of migratory birds (e.g., Sherry, T. W. and R. T. Holmes. 1995. "Summer versus winter limitation of Neotropical migrant landbird populations: what are the issues and what is the evidence?" In Ecology and management of Neotropical migratory birds: a synthesis and review of the critical issues., edited by T. Martin and D. Finch. Oxford, UK: Oxford Univ. Press. Close Sherry and Holmes 1995, Sherry, T. W. and R. T. Holmes. 1996a. Winter habitat limitation in Neotropical-Nearctic migrant birds: implications for population dynamics and conservation. Ecology no. 77:36-48. Close Sherry and Holmes 1996a, Faaborg, J., R. T. Holmes, A. D. Anders, K. L. Bildstein, K. M. Dugger, Jr. Gauthreaux, S. A., P. Heglund, K. A. Hobson, A. E. Jahn, D. H. Johnson, S. C. Latta, D. J. Levey, P. P. Marra, C. L. Merkord, E. Nol, S. I. Rothstein, T. W. Sherry, T. S. Sillett, F. R. Thompson III and N. Warnock. 2010b. Recent advances in understanding migration systems of New World land birds. Ecological Monographs no. 80 (1):3-48. Close Faaborg et al. 2010b), have all contributed to making the American Redstart a model species for understanding the ecology and evolution of long-distance migration ( Boulet, M. and D. R. Norris. 2006. "Introduction: The past and present of migratory connectivity." In Patterns of migratory connectivity in two Nearctic-Neotropical songbirds: New insights from intrinsic markers, edited by M. Boulet and D. R. Norris, 1-13. Washington, DC: American Ornithologists' Union. Close Boulet and Norris 2006), including habitat quality, seasonal interactions and mechanisms, carry-over effects, migratory connectivity, sexual selection, and year-round demography. These conceptual advances in redstarts have benefited from novel application of technologies like stable-isotope analysis, satellite imagery, and 3D territory overlap, as well as renewed emphasis on full annual cycle ecology and experimental hypothesis testing ( Sherry, T. W. and R. T. Holmes. 1995. "Summer versus winter limitation of Neotropical migrant landbird populations: what are the issues and what is the evidence?" In Ecology and management of Neotropical migratory birds: a synthesis and review of the critical issues., edited by T. Martin and D. Finch. Oxford, UK: Oxford Univ. Press. Close Sherry and Holmes 1995, Marra, P. P., K. A. Hobson and R. T. Holmes. 1998. Linking winter and summer events in a migratory bird by using stable-carbon isotopes. Science no. 282:1884-1886. Close Marra et al. 1998, Faaborg, J., R. T. Holmes, A. D. Anders, K. L. Bildstein, K. M. Dugger, Jr. Gauthreaux, S. A., P. Heglund, K. A. Hobson, A. E. Jahn, D. H. Johnson, S. C. Latta, D. J. Levey, P. P. Marra, C. L. Merkord, E. Nol, S. I. Rothstein, T. W. Sherry, T. S. Sillett, F. R. Thompson III and N. Warnock. 2010b. Recent advances in understanding migration systems of New World land birds. Ecological Monographs no. 80 (1):3-48. Close Faaborg et al. 2010b, Wilson, S., S. L. LaDeau, A. P. Tøttrup and P. P. Marra. 2011b. Range-wide effects of breeding- and nonbreeding-season climate on the abundance of a Neotropical migrant songbird. Ecology no. 92 (9):1789-1798. Close Wilson et al. 2011b, Tonra, C. M., P. P. Marra and R. L. Holberton. 2013. Experimental and observational studies of seasonal interactions between overlapping life history stages in a migratory bird. Hormones and Behavior no. 64 (5):825-832. Close Tonra et al. 2013, Cooper, N. W., T. W. Sherry and P. P. Marra. 2014. Modeling three-dimensional space use and overlap in birds. Auk no. 131 (4):681-693. Close Cooper et al. 2014).