It looks like the first sparrows where brought over in 1851, to control insects, and because they would have been familiar to people coming from Europe.
When Europeans first arrived in the Americas, there were Native American cities, but none of the species Europeans had come to expect in cities: no pigeons, no sparrows, not even any Norway rats. Even once European-style cities began to emerge, they seemed empty of birds and other large animals. In the late 1800s, a variety of young visionaries, chief among them Nicholas Pike, imagined that what was missing were the birds that live with humans and, he thought, eat our pests. Pike, about whom little is known, introduced about 16 birds into Brooklyn.
Interestingly, when the first birds were released in Brooklyn, New York, in 1851, they were legally protected. However, as they became more abundant, and people began to see them as pests, they lost their protected status.
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.
The Story of the Most Common Bird in the World
Reasons given for introduction were to establish wildlife familiar to European immigrants, or to control insect infestations. However, in agricultural areas, an average of 60% of the House Sparrows' diet consists of livestock feed (corn, wheat, oats, etc.), 18% cereals (grains from fields and in storage), 17% weed seeds, and only 4% from insects. Urban birds tend to eat more commercial birdseed, weed seed (e.g., crabgrass), and human scraps.
House Sparrow History
English house sparrows were first brought to New York around 1850. At the time, the city was facing a serious quandary: The snow-white linden moth was defoliating Manhattan Island, devouring its fruit trees and its leafy elms. City planners hoped that the sparrows would see the linden moth larvae as an all-you-can-eat buffet. And they did.
The Truth About Sparrows
It was just one, introduction at one time, there were quite a few different introductions over the years.
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