House Sparrows are a stout, stocky sparrow, with shorter legs and a thicker bill than native American sparrows. Members of both sexes are brown backed with black streaks throughout this area. Their undersides are pale buff. Males have white cheeks and a black bib, while females do not. The tail is usually three-quarters of the length of the wing. Males are slightly larger than females. Wing length is 76 mm and average mass is 28.5 grams.
House Sparrows are distributed almost worldwide, excluding the polar regions. They are native to the Palearctic and Ethiopian regions and have been introduced to the Nearctic, Neotropical, and Australian regions. Their introduction into North America occured in 1851, when a group of 100 birds from England was released in Brooklyn, New York.
In North America House Sparrows prefer areas that have been modified by humans, including farms, residential areas, and urban areas. They are absent from uninhabited woodlands, deserts, forests, and grasslands.
House Sparrows form monogamous pairs for each breeding season. Nests are built between February and May. House Sparrows nest in crevices inside and on buildings, and in coniferous and deciduous trees. Nests are built from dried vegetation, feathers, strings, and paper. Eggs are layed at any time in the nesting period. One to eight eggs can be present in a clutch, though there are usually 5, with the possiblity of four clutches per nesting season. Both males and females incubate the eggs for short periods of a few minutes each. Incubation lasts for 10 to 14 days. After the eggs are hatched, both males and females feed the young through regurgitation.
Both males and females incubate eggs and brood young until they have fledged. Both parents also provide their young with food.
A wild House Sparrow lived to be 13 years and 4 months old, though most will live for only several years.
House Sparrows tend to forage for food on the ground, using a hopping movement when not in flight. Their flight is direct, with continued flapping and no periods of gliding. House Sparrows aggressively protect a small territory just around their nesting site. This is believed to be strictly a protection of the nest site, and not of any feeding areas. Sparrows have been observed to threaten, and if necessary, attack 70 species of birds that have come into their nesting territory. In these attacks males attack males and females attack only females. House Sparrows are gregarious and active during the day. In North America there may be some local movements in response to weather changes but House Sparrow populations do not migrate extensively.
House Sparrows use a set of postures and behaviors to communicate with others of their species. House Sparrows also have a set of vocalizations that are used to attract mates, deter intruders, and warn others.
House sparrows eat various kinds of seeds supplemented by some insects. Rural birds tend to eat more waste seed from animal dung and seed from fields, while urban birds tend to eat more commercial birdseed, weed seed, and human trash. Studies of the contents of house sparrows' stomachs in Alabama, Connecticut, Illinois, Iowa, Massachusetts, Michigan, Missouri, Pennsylvania, and Vermont have shown approximate amounts of seed to be 60% livestock feed (corn, wheat, oats, etc.), 18% cereals (grains from storage or from fields), 17 % weed seed, and 4% insects.
Many hawks and owls hunt and feed on house sparrows. These include Cooper's hawks, merlins, snowy owls, eastern screech owls, and many others. Known predators of nesting young or eggs include cats, domestic dogs, raccoons, and many snakes. House sparrows avoid predation by foraging in small flocks so that there are many eyes watching out for potential predators.
House sparrows are abundant near human habitations. In these areas they serve as an important prey base for birds of prey and they may have an impact on plant communities because they consume large quantities of seeds. House sparrows seriously impact populations of native birds, such as bluebirds, chickadees, cliff swallows, and some woodpeckers. House sparrows take over the nesting cavities of native birds, including expelling adults and nestlings by force.
Because of their preference for human-modified habitats, house sparrows are considered a nuisance species, an aggressive competitor with native birds, and an agricultural pest. Large aggregations around buildings produce annoying noise and large quantities of feces.
House sparrows are well-suited for studies of general biological problems, such as the way animals evolve and pest control.
When first introduced into the United States in 1851, house sparrows were protected from predators and fed. However, populations expanded enormously in North America and they were soon considered a nuisance species. Since the 1960's, with the changes in farming to larger, single crop farms, populations have declined. They are not, however, seen as threatened and are not included in most Canadian and U.S. regulations.
Jennifer Roof (author), University of Michigan-Ann Arbor.
Lowther, Peter E. and Cink, Calvin L. 1992. The Birds of North America. No. 12. The American Ornithologists' Union.