How Did House Sparrows Get to America? An 1850s Import

The Brooklyn releases of the 1850s

In the mid-19th century, the shade trees of eastern American cities were being stripped by caterpillars, especially the larvae of a moth that dangled from the trees on silk threads. Many people believed a familiar European bird would solve the problem, and some immigrants simply missed the sparrows of home.

Members of the Brooklyn Institute arranged for sparrows to be shipped from England. A first small group was released in 1851 but apparently did not survive. A larger shipment, often said to be about 100 birds, followed in 1852; the birds were kept over the winter and released in 1852 and 1853, including at Green-Wood Cemetery in Brooklyn. Accounts of the exact dates and numbers differ, but this release is usually credited with founding the North American population.

The birds settled in quickly. They found plenty of food in streets full of horses, spilled grain and garbage, and plenty of nest holes in buildings, with few competitors used to living so close to people.

How did house sparrows spread across America?

The Brooklyn birds were only the beginning. Through the 1850s, 1860s and 1870s, sparrows were deliberately released in many other places, including Philadelphia, Boston, Salt Lake City and San Francisco, and they were moved from city to city by enthusiasts. Some towns imported birds directly from Europe; others caught sparrows in established cities and released them elsewhere.

Once established, the birds spread on their own. They followed railroads, feeding on grain spilled from freight cars and at stockyards, and settled in every new town and farm. By the end of the 19th century they occupied most of the eastern and central United States and southern Canada, and by the early 20th century they had reached the Pacific coast.

Today the house sparrow lives from Canada’s Northwest Territories south to Panama and is among the most widespread birds on the continent, most abundant in grain-growing regions such as the Midwest.

The “Sparrow War”

As sparrow numbers soared, opinion turned. In the 1870s and 1880s, American naturalists argued bitterly over whether the bird was a friend or a pest, a dispute later dubbed the “English Sparrow War.” The ornithologist Thomas Mayo Brewer defended the sparrow, while Elliott Coues led the attack against it.

In 1889, the U.S. Department of Agriculture published a long report by Walter B. Barrows, The English Sparrow in North America. Based on reports from thousands of correspondents, it concluded that the bird did more harm than good to crops and native birds and recommended stopping its protection and its further introduction. Several states that had once protected the sparrow reversed course.

The irony is that house sparrows mostly eat seeds, not caterpillars. Adults feed insects to their chicks, but they did little to solve the problem that inspired their import.

Effects on native birds

The biggest impact of house sparrows in North America is competition for nest holes. They take over birdhouses, woodpecker holes and other cavities used by native birds, including:

• Eastern bluebird, whose declines in the 20th century were partly blamed on sparrows and starlings taking its nest sites.
• Tree swallow and purple martin, which nest in boxes and cavities that sparrows also seek.
• Cliff swallow, whose mud nests sparrows sometimes occupy.

Male house sparrows defending a nest site can be aggressive, and they are known to break eggs and kill nestlings of other birds. Because of this, the house sparrow is widely regarded as an invasive species in North America.

House sparrows have also been linked to the spread of disease, for example carrying avian pox and avian malaria that harmed native forest birds in Hawaii. Their numbers in North America have themselves dropped by roughly 80% since the 1960s (see why are house sparrows declining?).

Where else were house sparrows introduced?

The 19th century was the era of “acclimatization societies,” groups that shipped European animals around the world. The house sparrow was one of their most successful exports.

Thanks to these releases, as well as birds that hitched rides on ships, the house sparrow has become the most widely distributed wild bird in the world. A few attempts failed, for example in Greenland and Cape Verde. Western Australia has prevented the species from settling by removing any sparrows that arrive.

Sparrows and starlings

The house sparrow was not the last European bird to be brought to North America. The European starling was released in New York’s Central Park in 1890 and 1891 and spread across the continent even faster (see how did starlings get to America?). Together, the two species are among the best-known examples of how a few well-meant releases can change the bird life of an entire continent.