The house sparrow or English sparrow (Passer domesticus) is one of the most widespread and abundant birds in the world and has been the subject of hundreds of studies. It occurs as an associate of humans in all 254 counties of Texas. It was first introduced into North America in 1850 at Brooklyn, New York, and J. M. Brown released two pairs at Galveston, Texas, in 1867 and made subsequent releases at intervals until 1872. Between 1880 and 1905 the species spread rapidly throughout the state. Years of the first recorded appearance of the house sparrow in selected cities and towns include Jefferson (1882), Houston (1884), San Saba (1886), Brownsville (1889), Gainesville and Waco (1892), San Angelo (1895), San Antonio (1896), Kerrville (1897), Colorado City (1899), Uvalde and Cotulla (1900), Langtry (1901), Texline and Canadian (1903), and Corpus Christi (1905). Some authorities credit the rapid spread of the house sparrow to roosting birds moving from one city to another in freight cars. Adverse to this idea is the appearance of the species in Rocksprings in 1900 and in Mobeetie in 1901; neither community was served by a railroad.
Selected biological data of the house sparrow include length, six inches; wingspan, nine inches; weight, one ounce. Its call is a cheep, chissis with various grating, twittering, or chirping notes. Its maximum speed of flight is thirty-three miles an hour. It usually spends its entire life in a very small area, but flocks may fly two to three miles from their roosts to feeding sites in grainfields. Foraging flocks and roosts sometimes contain several hundred birds. In some urban areas of Texas, house sparrows may greatly outnumber all other species of birds. Sexual display of house sparrows may begin as early as February and is followed by the building of nests in protected locations. Nests are placed from eight to thirty feet above the ground. Preferred sites are under the eaves of houses, in gutters, holes and crevices in buildings, or in tree cavities. The nest is roofed over and has an entrance hole in the side. The outer layer consists of grass or straw and the inner lining of softer materials, such as feathers, hair, string, fine grasses, or paper. Nests are commonly used year after year. House sparrows are slightly territorial and will defend the area immediately surrounding the nest. Egg laying begins during March and early April and extends through the middle of August. One to six clutches of eggs with one to six eggs a clutch may be laid. The eggs are incubated for ten to sixteen days; both the male and female share this responsibility. The young are naked when hatched but rapidly develop juvenile plumage and are fully feathered when they leave the nest, between the fifteenth and seventeenth days. The juvenile plumage is replaced as a result of a molt that begins four to six weeks after fledging. Thereafter the plumage is renewed annually by a molt that begins near the end of, or immediately following, the breeding season. The height of molt in both juvenile and adult sparrows in northwestern Texas occurs in September.
House sparrows are known to eat more than 830 different foods. Although the diet consists of less than 4 percent animal food, the eating of various species of harmful insects is considered to be beneficial. More insects are taken during the breeding season, when about two-thirds of the diet of the nestlings may consist of animal material. Plant foods eaten include cracked corn, oats, wheat, sorghums, barley, buckwheat, rice, millet, and seeds of such native plants as ragweed, crabgrass, smartweed, pigweed, amaranth, bristlegrass, witchgrass, Johnson grass, annual bluegrass, chickweed, and plantain. Cultivated fruits are sporadically damaged by house sparrows, which may also feed on buds, sprouts, and foliage of various fruit trees and garden plants. The feeding habits of house sparrows are, in their totality, considered to be detrimental to the interests of man.
More than forty species of ectoparasites, including mites, ticks, lice, flies, and fleas, have been reported from North American house sparrows. Sparrows are also susceptible to viral, bacterial, protozoan, and fungal diseases as well as infection by flukes, tapeworms, and roundworms. In Hale County, Texas, nestling house sparrows are involved in the amplification of western encephalitis virus, which can be passed to mosquitoes and then to humans.
Storms often kill large numbers of house sparrows. In October 1923 several hundred birds were killed by a hailstorm at Marfa. Predators on adult house sparrows include Cooper's and sharp-shinned hawks, screech owls, northern shrikes, and house cats. Grackles and fish crows are fond of the eggs and the young. The house wren and starling are competitors for nest sites, and both are known to destroy the eggs of the house sparrow. Although house sparrows suffer heavy mortality in their first year of life, there are records of individuals living to the age of eleven years in the wild and twelve years in captivity. House sparrows were initially observed to be very aggressive toward many species of native birds. Although this aggressive tendency is now somewhat abated, house sparrows still compete for nests and nest sites with such birds as martins, swallows, wrens, and bluebirds. House sparrows were originally protected in Texas by an 1883 law that prohibited the killing of any "sparrow." They are not protected today and are generally considered to be a nuisance species that must occasionally be controlled on a local basis. House sparrows can be readily maintained and bred in captivity and are used frequently as laboratory animals for experimental studies.