Original description: Peucaea carpalis Coues 1873
Taxonomic history in AOU/AOS Check-list
AOU 1 (1886): Rufous-winged Sparrow, Peucaea carpalis
AOU 2 (1895): Rufous-winged Sparrow, Peucaea carpalis
= AOU 3 (1910): Rufous-winged Sparrow, Aimophila carpalis
AOU 4 (1931): Rufous-winged Sparrow, Aimophila carpalis
AOU 5 (1957): Rufous-winged Sparrow, Aimophila carpalis carpalis
AOU 6 (1983): Rufous-winged Sparrow, Aimophila carpalis
AOU 7 (1998): Rufous-winged Sparrow, Aimophila carpalis
Coues named Charles Bendire’s “homely little bird” Peucaea carpalis (“shouldered,” in reference to the species’ rusty lesser coverts), and suggested that it was most closely related to the Rufous-crowned Sparrow. In 1899, the American Ornithologists’ Union reclassified both of those species as members of the genus Aimophila, following a recommendation made “provisionally” by Robert Ridgway in the same number of the Auk.
Over much of the twentieth century, ornithology wrestled with the Aimophila problem, attempting to sort the species into groups of evolutionarily allied taxa and to create a scheme that would reflect the relationships among those groups. In 1955, Robert W. Storer identified two clusters of species, one inhabiting arid tropical scrub and the other inhabiting temperate grassland and savanna; unfortunately, Storer found that four of the species traditionally assigned to Aimophila did not fit comfortably into either group, and he thus declined to recommend that the genus be split. An ambitious study published in 1977 identified three species groups (plus the Five-striped Sparrow, then still considered an Aimophila), “which had separate evolutionary histories and probably are not as closely related to each other as some earlier authors thought.” Like Storer, Wolf concluded that radiation within each group had proceeded in a different ecological setting: the thorn forests of Middle America, pine-oak woodland in Middle America, and “weedy, open country of Middle America and [the] United States.” He too stopped short of proposing a new generic classification, suspecting that one or the other of these groups might prove more closely related to other passerellid genera than to the remaining members of Aimophila.
More substantial progress came as morphological analysis yielded to molecular study in taxonomy. In 2003, Rebecca J. Carson and Greg S. Spicer analyzed three mitochondrial genes across 34 species of passerellid sparrow, producing several phylogenetic trees that all placed the Rufous-crowned Sparrow nearer the “brown” towhees and the Cassin and Bachman Sparrows nearer the Grasshopper Sparrow, confirming the paraphyly of the traditional Aimophila at least for those three species.
Six years later, another study, this one treating all thirteen of the Aimophila species then recognized, affirmed that the Rufous-crowned, Rusty, and Oaxaca Sparrows were only distantly related to the other members of the genus as traditionally understood, and that South America’s Tumbes and Stripe-capped Sparrows likewise stood apart. The remaining Aimophila—the Bachman, Cassin, Botteri, Black-chested, Bridled, Stripe-headed, Rufous-winged, and Cinnamon-tailed Sparrows—were found to cluster neatly with the Grasshopper Sparrow (and its South American relatives). DaCosta and his co-authors suggested that the name Aimophila, founded originally on the Rusty Sparrow, should apply only to the first three species, while Rhynchospiza should be revived for the Tumbes and Stripe-capped Sparrows. The clade including the rest of the species would require a name of its own: Audubon’s venerable Peucaea, erected in 1839 for the Bachman Sparrow.
The American Ornithologists’ Union endorsed the change in its 2010 Supplement to the Check-list, removing the Rufous-winged Sparrow and its clade mates from the old, broad Aimophila and formally placing them in the resurrected Peucaea.
Relationships
The Rufous-winged Sparrow’s closest relative is currently thought to be the quite similar Cinnamon-tailed Sparrow, Peucaea sumichrasti. All other Peucaea sparrows are more closely allied to one another than any is to either the Rufous-winged or the Cinnamon-tailed Sparrow, an affirmation of the grouping proposed by Robert Ridgway more than a century ago.
IUCN Conservation Status: Of least concern
Though Rufous-winged Sparrow populations appear to be robust at present, their historical vacillation and restricted range suggests that the species’ status is tenuous. In Arizona, where the bulk of the species’ United States range is within a short distance of the suburban sprawl of Tucson, development and urbanization are likely to pose considerable local risk. Rufous-winged Sparrows do occur in low-density residential areas, but their breeding success in such marginal habitats, which among other dangers host populations of free-roaming housecats, is unknown.
The drastic decline of the Rufous-winged Sparrow in southeast Arizona in the 1880s was likely due at least in part to vegetation changes caused by overgrazing, which reduces grass cover and encourages dense stands of woody vegetation, all to the detriment to the sparrow.
Behavior: The Peucaea sparrows are among the most furtive of North American birds. The Rufous-winged Sparrow provides a mild exception to the rule, and even when it is not singing, this is a fairly easy bird to find and to watch. Almost all foraging is on the ground, often in the shade of a mesquite tree; feeding birds hop slowly through the grass, stopping to spend sometimes minutes at a time in the search for insects and seeds. If disturbed, they often simply scamper a few feet deeper into the grass and resume feeding. They seem to quickly lose interest in quiet and patient observers, and often pick their way back along the ground to feed unconcerned at very close range.
If startled or hard pressed by a human or other potential predator, Rufous-winged Sparrows fly off in surprisingly strong, swooping flight. Unlike Chipping or American Tree Sparrows, they only rarely flee into the tops and outer branches of trees, instead landing in denser vegetation low in a mesquite or other thorny bush.
Males sing from conspicuous perches in low mesquites or other trees, usually no more than fifteen feet from the ground, though they may exceptionally sing from a roof or telephone wire.
Voice: Male Rufous-winged Sparrows sing nearly throughout the year, with peaks discernible in wet springs and especially during the late summer monsoon period, when many nest. Nearly three dozen different song types have been described in this species. The basic pattern common to most songs is a series of chipping or lisping notes followed by a trill; the trill may be higher or lower than the introductory notes. Some songs lack the initial notes, and the trill can then be reminiscent of the song of the Canyon Towhee. In some songs, the trill is very fast and dry, resembling that of a Chipping Sparrow or Worm-eating Warbler; in others, it is slow and loose, like a Pine Warbler’s or distant Northern Cardinal’s song. A warbling vocalization, also given only by males and in some individuals reminiscent of a brief Common Yellowthroat song, may serve as pair recognition or a summons to reunion when feeding groups have scattered.
The most distinctive call notes of this species is a frequently heard low-pitched and rich plipt, fuller than the thin chips of many other sparrows; this note or one very like it is repeated to form the introduction of some male songs. There is also a high, silvery teep, recalling the calls of the Black-throated Sparrow, or even an insect, but with a decided and abrupt decay.
Detailed description and measurements drawn from standard reference works
Adult Peucaea carpalis carpalis: Tail feathers brownish gray with very narrow paler edges. Upper tail coverts and rump gray-brown. Back and scapulars gray-brown, the feathers with broad darker shaft streaks and faintly grayer edges, forming sparse streaks. Primaries and secondaries gray with faintly paler edges. Tertials gray with dull gray-buff to gray edges on outer web. Greater and median coverts dark gray-brown with dull whitish or buffy-white edges and tips, forming two wing bars. Lesser coverts, often concealed by drooped scapulars, bright chestnut brown. Marginal coverts of under wing white. Nape gray with two parallel rusty streaks, continued from crown.
Under tail coverts tinged buffy; vent, belly, and breast pale gray to grayish white. Flanks with faint buffy tinge. Throat whitish to white, separated from whitish jaw stripe by neat, narrow black lateral throat stripe. Ear coverts grayish.
Crown with broad rusty stripes and narrow gray streaks, the gray often forming a central crown stripe. Grayish ear coverts separated from whitish jaw stripe by neat, narrow black whisker and bordered above by rusty line behind eye. Narrow white eye ring, usually broken in front and at rear. Broad gray supercilium bordered below by rusty line behind eye; paler whitish in front of eye. Whitish lore usually crossed by very narrow rusty or blackish line.
Tarsus and toes pinkish yellow. Thick-based, rather stumpy bill yellow below, gray above with yellow edges.
Juvenile Peucaea carpalis carpalis: Tail feathers brownish with very narrow paler edges. Upper tail coverts and rump gray-brown. Back and scapulars buffy brown, the feathers with darker brown shaft streaks and paler brownish edges, forming sparse streaks. Primaries and secondaries brownish with faintly paler edges. Tertials brown-gray with dull buffy edges on outer web. Greater and median coverts dark brown with dull buffy edges and tips, forming two wing bars. Lesser coverts brown to chestnut brown. Marginal coverts of under wing white. Nape buffy gray with fine brownish streaks, continued from crown.
Under tail coverts, vent, belly, flanks, and breast pale buffy to buffy gray with dusky streaks concentrated on breast and flanks. Throat grayish or whitish, separated from buffy whitish jaw stripe by narrow sooty brown lateral throat stripe. Ear coverts grayish with scattered brown streaks or spots.
Crown grayish brown with broad dark brown streaks. Ear coverts separated from buffy whitish jaw stripe by narrow sooty brown whisker and bordered above by dark brown line behind eye. Narrow white eye ring, usually broken in front and at rear. Broad gray-brown supercilium bordered below by dark brown line behind eye; grayer in front of eye. Whitish or buffy lore usually crossed by very narrow blackish line.
Tarsus and toes pinkish yellow. Thick-based, rather stumpy bill yellowish pink below, gray above with yellowish edges.
Length 123-136 mm (4.8-5.4 inches)
Wing 53-65 mm (2.1-2.6 inches)
Tail 57-69 mm (2.2-27 inches)
W:T 0.97
Mass 13-17 g
