The black-throated sparrow (Amphispiza bilineata), also known as the desert sparrow or New World sparrow is present in San Bernardino County in plentiful numbers, as is it in the southwestern United States and Mexico.
It is referred to as the desert sparrow due to its preferred habitat of arid desert hillsides and scrub. These birds, however, should not be confused with the desert sparrows of Africa and Asia.
Black-throated sparrows are roughly 4.5 inches to 5.5 inches in length. They are pale gray on top, with a distinctive black and white head pattern. These birds’ throats do not turn black until they mature.
Black-throated Sparrows are very common in the Mojave Desert, living in a variety of dry open areas, including in barren flats of creosote bush which most birds avoid. They thrive as well among Mojave shrubs and cacti, and in saltbush. They occur as well in grasslands and pinyon-juniper woods.
In winter, flocks feed on the ground in open areas, making little tinkling, metallic and shrill callnotes and trills. In spring during the mating season, males perch atop low bushes to sing, using their high and bell-like song to defend nesting territory. Though larger groups may accumulate around sources of desert water, they travel generally in small groups.
Black throated sparrows feed mostly on seeds and insects, dining more on seeds in the winter and more on insects in the summer. They also devour fresh green shoots, other green vegetation, and ripe berries and fruits when available. They can survive without water for extended periods during the drier part of the year, drawing liquid from insects and green plants. The young are fed mostly insects.
They forage primarily while scampering on the ground but occasionally forage up in shrubs and desert trees. When an opportunity presents itself, they will make short flights to catch insects in mid-air.
They create loose nests of grass twigs and plant fibers carefully hidden in brush six to eighteen inches above the ground. The female of the species typically lays three or four white or pale blue eggs.
The nesting activity can vary with the timing of rains. A typical nest site is in a low shrub or branching cactus, well hidden and usually within 2 feet of the ground. Nests are sometimes located on the ground at base of shrub. A nest is bulky and sturdy, entailing an open cup of grass, weeds, plant fibers, and small twigs, lined with fine grass, plant down, and often with animal hair. Both parents will feed the nestlings once they hatch. A pair will often raise two broods per year.
Unlike some desert birds, the black throated sparrow has not adopted well to encroaching civilization and development. As a result, their numbers have declined in some areas. In their undisturbed habitat, these birds are yet widespread and common.
The black throated sparrow is a permanent resident in much of the Southwest, but migrates farther north. Its northern limit of breeding range may vary from year to year, with occasional northward “invasions.” Strays sometimes wander as far east as the Atlantic Coast.