The Greater Pewee is a member of the widespread genus Contopus which includes more than a dozen species ranging from Alaska to Argentina. The visually distinctive features of this plain, gray flycatcher are a spiky, tufted crest and a yellow-orange lower mandible contrasting with a dark upper one. In the United States and Mexico, the Greater Pewee (subspecies C. p. pertinax) is most easily identified by its territorial song Ho-say ma-ree-ah, which gives the bird one of its Spanish names.
In its pine (Pinus spp.) or pine-oak (Quercus spp.) breeding habitat, the Greater Pewee forages for flying insects by sallying from an exposed branch tip in the upper half of a tall conifer, usually a pine. The perch height used by this species is intermediate between those used by its close relatives breeding in the western United States: the Olive-sided Flycatcher (C. cooperi) forages from treetops, and the Western Wood-Pewee (C. sordidulus) forages from low branches. Through the day the male Greater Pewee moves around the perimeter of his large territory, feeding and singing.
This flycatcher vigorously attacks potential predators, including the Acorn Woodpecker (Melanerpes formicivorus), Steller's Jay (Cyanocitta stelleri), and squirrels (Sciurus spp.). Some other passerines, including the Plumbeous Vireo (Vireo plumbeus), Hepatic Tanager (Piranga flava), and Olive Warbler (Peucedramus taeniatus), often build their nests near nesting Greater Pewees, perhaps gaining protection from predators in doing so.
Migratory behavior of the Greater Pewee varies within its range. In the northern portion—Arizona, New Mexico, and northern Sonora (and probably northwestern Chihuahua), Mexico—most individuals are short-distance migrants. Further south in Mexico, some individuals are nonmigratory and remain in their breeding habitat year-round, while others migrate altitudinally to winter in riparian vegetation. At the southern end of the range in Belize, El Salvador, Guatemala, and Honduras, birds remain in their pine-oak breeding habitat all year.
The Greater Pewee was formerly called Coues's or Coues' Flycatcher (Am. Ornithol. Union American Ornithologists' Union 1983 and American Ornithologists' Union 1998a), honoring Elliot Coues, an army physician and ornithologist, who collected and described the species (Mearns and Mearns 1992a).
The reference list for this account contains many well-known names in ornithology, but none focused their studies on Greater Pewee. Nevertheless, the combination of details from their work provides basic information about the species and raises intriguing questions. The song of the southern subspecies, C. p. minor, is similar to that of the Dark Pewee (C. lugubris) of Costa Rica and western Panama (Skutch 1977), suggesting further studies of the taxonomy within the Greater Pewee and between other taxa are needed. Many other topics for further research are apparent from the data gaps in this account.
All data presented here are for C. p. pertinax, unless otherwise noted.