The House Sparrow (Passer domesticus), is a member of the Old World sparrow family Passeridae. This bird is loosely considered a relative of the Weaver Finch family. It occurs naturally in most of Europe and much of Asia. It has also followed humans all over the world and has been intentionally or accidentally introduced to most of the Americas, sub-Saharan Africa, New Zealand and Australia as well as urban areas in other parts of the world. It is now the most widely distributed wild bird on the planet.
The House Sparrow is about 6 inches long. The male House Sparrow has a gray crown, cheeks and underparts, black on the throat, upper breast and between the bill and eyes. The bill in summer is blue-black, and the legs are brown. In winter the plumage is dulled by pale edgings, and the bill is yellowish brown. The female has no black on head or throat, nor a gray crown. Her upperparts are streaked with brown. The juveniles are deeper brown, and the white is replaced by buff; the beak is dull yellow. The House Sparrow is often confused with the smaller and slimmer Tree Sparrow, which, however, has a chestnut and not gray crown, two distinct wing bars, and a black patch on each cheek.
The House Sparrow is gregarious at all seasons in its nesting colonies, when feeding and in communal roosts. In spring, flowers (especially those with yellow colors) are often eaten. Crocuses, primroses and aconites seem to attract the house sparrow most. The bird will also hunt butterflies. Although the Sparrows’ young are fed on the larvae of insects, often destructive species, this species eats seeds, including grain where it is available.
The House Sparrow nests in holes in masonry or rocks, in ivy or creepers on houses or banks, on the sea-cliffs, or in bushes in bays and inlets. When built in holes or ivy, the nest is an untidy litter of straw and rubbish, abundantly filled with feathers. Large, well-constructed domed nests are often built when the bird nests in trees or shrubs, especially in rural areas. Five to six eggs, profusely dusted, speckled or blotched with black, brown or ash-gray on a blue-tinted or creamy white ground, are usual types of the very variable eggs. They are variable in size and shape as well as markings. Eggs are incubated by the female. The House Sparrow has the shortest incubation period of all the birds: 10-12 days and a female can lay 25 eggs a summer in New England.
Although only an introduced species to North America in the late 19th century, the House Sparrow is one of the most abundant birds there and the population is estimated at approximately 150 million. It is one of only three birds in United States and Canada that is not protected by law. As an invasive non-indigenous species, it is legal to kill House Sparrows and destroy their eggs at any time in most places in the United States.
Because the House Sparrow is smaller than the less aggressive native birds with which it competes, it is impossible to keep them out of nest boxes built for many native birds. Attempts to counter the effects of the House Sparrow on native bird populations include the trapping and shooting of adults and the destruction of their nests and eggs.