House Sparrows aren’t related to other North American sparrows, and they’re differently shaped. House Sparrows are chunkier, fuller in the chest, with a larger, rounded head, shorter tail, and stouter bill than most American sparrows. They measure 15 to 17 centimters in length, with a wingspan of 19 to 25 centimters. Male House Sparrows are brightly colored birds with gray heads, white cheeks, a black bib, and rufous neck – although in cities you may see some that are dull and grubby. Females are a plain buffy-brown overall with dingy gray-brown underparts. Their backs are noticeably striped with buff, black, and brown. House Sparrows are noisy sparrows that flutter down from eaves and fencerows to hop and peck at crumbs or birdseed. Look for them flying in and out of nest holes hidden behind shop signs or in traffic lights, or hanging around parking lots waiting for crumbs and picking insects off car grills. House Sparrows have lived around humans for centuries. Look for them on city streets, taking handouts in parks and zoos, or cheeping from a perch on your roof or trees in your yard. House Sparrows are absent from undisturbed forests and grasslands, but they’re common in countryside around farmsteads. This species is of low conservation concern.
The House Sparrow was introduced into Brooklyn, New York, in 1851. By 1900 it had spread to the Rocky Mountains. Two more introductions in the early 1870s, in San Francisco and Salt Lake City, aided the bird’s spread throughout the West. House Sparrows are now common across all of North America except Alaska and far northern Canada.
The House Sparrow takes frequent dust baths. It throws soil and dust over its body feathers, just as if it were bathing with water. In doing so, a sparrow may make a small depression in the ground, and sometimes defends this spot against other sparrows.
The House Sparrow prefers to nest in manmade structures such as eaves or walls of buildings, street lights, and nest boxes instead of in natural nest sites such as holes in trees.
Due to its abundance, ease to raise and general lack of fear towards humans, the House Sparrow has proved to be an excellent model organism for many avian biological studies. To date, there have been almost 5,000 scientific papers published with the House Sparrow as the study species.
House Sparrows in flocks have a pecking order much the way chickens in a farmyard do. You can begin to decipher the standings by paying attention to the black throats of the males. Males with larger patches of black tend to be older and dominant over males with less black. By wearing this information on their feathers, sparrows can avoid some fights and thereby save energy.
Source: House Sparrow Overview and Identification Information, All About Birds, The Cornell Lab of Ornithology