The Buff-breasted Flycatcher is the smallest and most readily identifiable member of the genus Empidonax in the United States; it is by far the rarest. Its bright cinnamon breast and brown back provide a striking contrast to the other more drably plumaged members of its genus, particularly after fall molt. Although most U.S. birders know this flycatcher as a rare “southeastern Arizona specialty,” it actually occurs quite widely south of the United States in Mexico and Central America. In Mexico it occupies much of the higher mountains in western and southern portions of the country. Throughout its range, it prefers open pine-oak woodlands and montane riparian forests.
Many aspects of the life history of this species remain poorly known; its taxonomy is especially confusing. Its breeding biology has been studied only in Arizona, where it builds its nests of plant fibers and spiderwebs and usually places them in a conifer with a protective branch or stub overhead. This protective overhang may shield the nest and its occupants from rain, reduce radiative heat loss on cold summer nights, and perhaps deter parasitic cowbirds. Three to four creamy white eggs are laid in late May and June.
Although resident in most of its range, the Buff-breasted Flycatcher leaves Arizona and northern Sonora, Mexico, during the winter. Little is known about its wintering ecology. In Arizona, populations decreased markedly from the late 1800s until about 1970, probably owing to fire suppression and overgrazing of preferred habitat, mountain meadows. The U.S. population has increased since then but remains low, with only 20 to 40 individuals known annually in the 1980s. Fire may open new habitat for this species by clearing dense undergrowth which inhibits foraging.