Damage

House sparrow, Passer domesticus. Male (left) and female (right).

House sparrows consume grains in fields and in storage. They do not move great distances into grain fields, preferring to stay close to the shelter of hedgerows. Localized damage can be considerable since sparrows often feed in large numbers over a small area. Sparrows damage crops by pecking seeds, seedlings, buds, flowers, vegetables, and maturing fruits. They interfere with the production of livestock, particularly poultry, by consuming and contaminating feed. Because they live in such close association with humans, they are a factor in the dissemination of diseases (chlamydiosis, coccidiosis, erysipeloid, Newcastle’s, parathypoid, pullorum, salmonellosis, transmissible gastroenteritis, tuberculosis, various encephalitis viruses, vibriosis, and yersinosis), internal parasites (acariasis, schistosomiasis, taeniasis, toxoplasmosis, and trichomoniasis), and household pests (bed bugs, carpet beetles, clothes moths, fleas, lice, mites, and ticks).

In grain storage facilities, fecal contamination probably results in as much monetary loss as does the actual consumption of grain. House sparrow droppings and feathers create janitorial problems as well as hazardous, unsanitary, and odoriferous situations inside and outside of buildings and sidewalks under roosting areas. Damage can also be caused by the pecking of rigid foam insulation inside buildings. The bulky, flammable nests of house sparrows are a potential fire hazard. The chattering of the flock on a roost is an annoyance to nearby human residents.

Nestlings are primarily fed insects, some of which are beneficial and some harmful to humans. Adult house sparrows compete with native, insectivorous birds. Martins and bluebirds, in particular, have been crowded out by sparrows that drive them away and destroy their eggs and young. House sparrows generally compete with native species for favored nest sites.

Legal Status

The house sparrow is afforded no legal protection by federal statutes because it is an introduced species. A few states, however, may offer them some protection by requiring permits or otherwise restricting control activities. Check with state or local governments before poisoning or shooting house sparrows.

Economics of Damage and Control

Barrows (1889) published the results of a US Department of Agriculture survey concerning the status of house sparrows in 1886, about 35 years after their successful introduction. By this time, house sparrows were recognized as a detriment to agriculture and native birds. Kalmbach (1940) analyzed 8,004 sparrow stomachs and found that only 20% of the foods (primarily insects) taken by adult sparrows were beneficial to humans, 25% were of neutral importance, and 55% were definitely detrimental to human interests. While 59% of nestling foods were beneficial to humans and only 28% injurious, he pointed out that their impact lasted for only 10 to 12 days.

A recent survey of bird problems across the United States indicated that 25% of the respondents in cities had problems with house sparrows, behind pigeons (71%), blackbirds (54%), and starlings (42%) (Fitzwater 1988). Extensive measures with traps are not cost-effective.