and feet are dark brown or dusky, and the bill is small, stout, and pink. Recent fledglings may have darker bills, as well as notably short tails, yellow , and paler gray heads. Voice Its call is a high, soft tsip or stip. In flight it gives a soft ssip, a call said to resemble that of the chipping sparrow. The song is a series of clear, high-pitched whistles that accelerate into a rapid trill, which typically rises in pitch. Though similar to the song of the field sparrow, it is higher-pitched and more "mechanical". The accelerating trill is said to sound like a dropped ping pong ball. Similar species The combination of gray head and body is unique among New World sparrows. Though similar in plumage to the dark-eyed junco, the black-chinned sparrow is slimmer, and has a streaked back, brown edges to its wing feathers, and no white in its tail. Range and habitat The black-chinned sparrow breeds in the southwestern United States and throughout much of Mexico north of the Isthmus of Tehuantepec. It is regularly found from northern California east to western Texas, and as far north as southern Nevada and Utah, and has occurred as a or occasional breeder in Oregon and Colorado. A species of arid and semi-arid places, it lives in chaparral, sagebrush, pine-juniper woodlands, and other brushy shrubland. Much of its habitat is in remote, rugged, and rocky areas. It is significantly less common in edge habitat, and rare near the coast. It is found at elevations ranging from near sea level to in the United States, and from in Mexico. Some birds in Utah may move into desert ecotones as part of a post-breeding dispersal and some northern populations move into Chihuahuan Desert scrub during the winter. Most northern populations move south – primarily into Mexico – during the winter; some move to lower elevations as well. During migration, it is sometimes recorded in montane oak forest, but not in mixed pine-oak forest. Behavior Although the black-chinned sparrow appears to be relatively common where it occurs, it is an inconspicuous species that can be easy to overlook. In Mexico, it is generally found singly or in pairs, and only rarely in small groups. In the United States, it is sometimes found in small, loose groups, occasionally mingling with Brewer's or chipping sparrows. It flies close to the ground, with an undulating