House Sparrows

You see them everywhere… singing outside your bedroom window, eating squashed bugs off your car windshield, cleaning up spilled crumbs at sidewalk cafes. They mob bird feeders full of millet and take up space in nest boxes intended for other species. I’ve even found them in a tiny town in the middle of the Utah desert, miles from anything wet or green. One would think that House Sparrows are one of the most successful species ever to populate planet Earth.

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Male House Sparrow

Not closely related to North American sparrows, House Sparrows are relative newcomers to the Western Hemisphere. They were deliberately introduced during the latter half of the 19th century in repeated attempts to establish a breeding population in the U.S.

While the story is a bit foggy, apparently the birds were imported to eat insects that were damaging crops. If so, it was an egregious error. House Sparrows are primarily seed eaters, and according to one study, 78% of those seeds come from agricultural crops intended for livestock or human consumption.

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Female House Sparrow

As early as 1887, people were becoming aware of the mistake that had been made. States began to pass laws encouraging the extermination of the immigrants, but it was far too late. There are now approximately 150 million House Sparrows living in the Western Hemisphere—from Canada to Central America, and throughout the temperate parts of South America.

As the numbers of House Sparrows soared, they began to have a detrimental impact on several species, including Tree Swallows and Purple Martins. However, the most serious repercussions involved bluebirds.

For a variety of reasons, bluebird populations took a nose-dive during the early 1900s.  Winters during the 1890s were exceptionally severe, and many birds died. It takes time for populations to recover, and the repeated cold weather was very damaging, at least to Eastern Bluebird numbers (no one was counting Western and Mountain Bluebirds at that time).

Both bluebirds and House Sparrows nest in holes excavated by woodpeckers. During the last several hundred years, much land that used to be forested has been cleared for farming. So much land has been cleared that there are few trees available for perching and nesting. Also, because dead trees are now routinely cut down, fewer rotting trees with holes in them are available for the birds to use. If the birds can’t find a suitable cavity for their nest, they are unable to breed for that season.

Of the two species, House Sparrows are much more aggressive than the even-tempered bluebirds. They will evict bluebirds from their homes, often killing both the nestlings and the parents in the process. People who provide nest boxes for birds such as bluebirds, swallows, chickadees and nuthatches are responsible to ensure that no House Sparrows harass their tenants.

In a curious case of come-uppance, the House Sparrow is actually the victim of another introduced species, the House Finch. While House Finches are native to the west, they were limited in their range until a number of birds were released on Long Island, NY, in the 1940s. The highly adaptable species quickly colonized its new territory. House Finches are now found from northern Florida into Canada. At least in the eastern U.S., as the newcomer finches usurp food and nest sites, House Sparrow numbers have decreased. (See www.birds.cornell.edu for more information.)

While most birdwatchers in the U.S. consider House Sparrows anathema, the situation is strikingly different in Europe. In their native habitat, these birds are in serious trouble. Recent surveys show a 60% decrease in sparrow populations in Great Britain and western Europe. (Other songbirds are also experiencing significant reductions in population numbers.) The causes are unknown, and probably complex, although habitat destruction must play a significant role. It is certainly ironic that a bird considered a pest species in our country is now on the threatened species list at home.

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3 Responses to House Sparrows

  1. Lawry Sager says:

    The story of these birds arrival in the U.S isn’t necessarily “foggy”, heck, I’ll bet you could get all the details on the web.
    The way I’ve always heard it…some chap from across the pond thought that we should have all the bird species mentioned by the Immortal Bard. So…some were brought and released in NYC where they did quite well, thank you, eating seeds from the abundant horse apples in that busy city. A prominent Boston physician-can’t recall his name, but something of an ornithologist, if memory serves-actually called for the extermination of Loggerhead -or both N.A. species of-Shrikes! Yikes! This part can be found in one of Edward Forbush’s “Birds of Massachusetts” set from a century ago.
    But I really checked out this site because I wondered about the connection between weaver finches and MT. Plovers, a species that I’ve worked with in the field and have a gained a certain affinity for.
    I’ll be back.

  2. Lawry Sager says:

    Oops! Shouldn’t try to think when I’m tired…a couple correction are in order.
    It was the “American Acclimatization Society” that decided we needed House Sparrows in the U.S. and several attempts were made to introduce them. First successful intro apparently around 1850 in Brooklyn, NY. (Hawaiian ones came from New Zealand).
    And the good doctor who would kill shrikes to save the “sparrows”? Thomas Brewster, best known then for his book about oology (birds eggs), and his name on both that spiffy little Spizella, Brewer’s Sparrow, and, of course, Brewer’s Blackbird. Bueno, bye!

  3. LAH says:

    Lawry,
    I said it was foggy because in an extensive web search, I found a number of conflicting “authentic” stories. Rather than take the time to sort them all out, for what is really an aside in my article, I just called it foggy and moved on.

    The “Shakespeare” birds were European Starlings, as I mentioned in my later article on that topic.

    I appreciate your comments, providing information I omitted. Thanks!

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