Nestling: no down, yellow gape flanges, red mouth
Fledgling: underparts grayish, upperparts brownish
Adult Female: back and wings brown with dark streaks
Adult Male: black bill mask, throat, and breast, white stripe on shoulder
Adult Size: approximately 6.25″ long and weigh 28 grams
In the mid-1800’s, little brown House Sparrows were introduced into Brooklyn, New York, from Europe to establish wildlife familiar to European immigrants and it was also believed, that these birds would control the canker worms infesting trees in city parks. This notion proved to be incorrect since only 4% of the House Sparrows’ diet consists of insects. Because House Sparrows have no known predator, these highly adaptable birds have made themselves comfortable, spreading their wings across all of North American in vast numbers. These songbirds are the most abundant on this continent, with an estimated 150 million birds established in 48 states. House Sparrows are cavity-nesters making their nests in holes of buildings and other structures such as streetlights, signs, house eaves, traffic lights, vines climbing the walls of buildings, and in dryer vents.
MAJOR THREATS TO OUR NATIVE SPECIES
House Sparrows are strong competitors for nest boxes, at times displacing the species the nest box was intended for, such as bluebirds, swallows, and purple martins.
House Sparrows aggressively claim and defend prime nesting sites and often displace other species that have established a nest and are incubating a clutch.
House Sparrows breed earlier than other species, so once the male establishes a territory, he remains there year-round and starts defending that territory early in the season. This activity often prevents later-arriving species from nesting.
House Sparrows are known to evict other nesting birds, destroying their eggs, killing their nestlings and sometimes even killing the incubating female.
House Sparrows also discourage other birds from foraging in the same area.
House Sparrows are prolific breeders, raising up to four broods per season (compared to just one or two for bluebirds), each brood averaging four to five eggs. They are excellent nest builders and rebuild nests at a rapid rate. Eggs hatch in 11 days, babies fledge in 14 days. Young are independent in 7-10 days after leaving the nest. House Sparrows also have a relatively long lifespan.