![]() ![]() House sparrows may be highly adaptable, but that doesn’t mean they can thrive with every modification humans make to the environment. The answer likely lies in a combination of factors, all tied to rapid changes in both cities and farms. Theories abound as to why house sparrows have declined. Photo © Brian Henderson / Flickr Sparrow Falling What happened? A house sparrow scrounging crumbs in an urban area. European countries now recognize a World Sparrow Day to raise awareness of the plight of this once-abundant species. While the United Kingdom population has recently stabilized, the bird remains of concern to conservationists. The species is listed by the Royal Society for the Protection of Birds as a species of high conservation concern. In England, house sparrow populations have declined by half. However, the bird is experiencing similar declines in many parts of its native habitat, including the United Kingdom and Western Europe. After all, house sparrows compete with native species and are generally viewed as a pest. Many birders view this as a good-news story. In Philadelphia, the city where the sparrows were introduced to control inchworms, the birds have largely disappeared. According to the Cornell Lab of Ornithology, house sparrow numbers in North America have declined by 84 percent since 1966. The house sparrow appears to be a clear winner in the Anthropocene: an adaptable bird capable of thriving equally well on cities and in farms.īut over the past few decades, ornithologists have noted a new trend: house sparrows are in widespread decline. ![]() The sparrows, according to the research, diverged from other Old World sparrows around 11,000 years ago, just as agriculture was taking hold in the Middle East. The researchers hypothesized that these changes helped sparrows adapt to human settlements dominated by agricultural fields and livestock. Recent research published in the Proceedings of the Royal Society B found that house sparrows underwent genetic changes, including modified skull development and a gene that helps create the enzyme amylase that helps break down starch. A house sparrow at the Merced National Wildlife Refuge, California. But by then the bird was firmly established – and spreading. By the 1880s, just three decades after the first introduction, several U.S. Public sentiment turned quickly against the house sparrow. Backyard birders who erect birdhouses have undoubtedly noticed house sparrows bullying wrens and other native species. It nests in cavities, and pushed out native species like Eastern bluebirds. The house sparrow is also an aggressive little bird. They thrive on a variety of foods, including spilled grain and even garbage. As with so many such pest control efforts, the cure proved worse than the disease. For instance, their 1868 introduction to Philadelphia was apparently an effort to control inchworms. The reason for many of these reasons was for pest control. Ornithologists and others raised concerns over the merits of house sparrows, but their arguments proved futile against sparrow enthusiasts releasing cages full of birds. Nest boxes were installed in cities to increase sparrow populations. However, this set off a wave of introductions throughout the United States.įor a time, some sources refer to a “ sparrow fad,” with private individuals breeding birds, and others catching them and releasing them into new areas. The first introduction to North America was to New York City in 1851 or 1852, although the 8 pairs released seemed to fare poorly. It is the most widespread wild bird on earth.Īs with many aspects of conservation history, many of the details of sparrow introductions are poorly documented. Largely due to intentional releases by humans, house sparrows are now found on every continent except Antarctica, as well as many islands. The house sparrow ( Passer domesticus) is native to Eurasia, but beginning in the mid-1800s, it spread around the globe. The real story of their spread and decline is a bit more complex, and may have implications for urban conservation. House sparrows are often considered one of the most adaptable birds, capable of thriving amongst our farms, suburbs and cities. ![]() Given their constant presence, it seems odd to be writing this: House sparrow populations have been declining worldwide, including in their native range. They cheep incessantly, often drowning out other birdsong. I look out my window, and they’re everywhere: hundreds of house sparrows flit around our shrubs, hop around the yard, and steal food from our backyard chickens.Īt this time of year, the males puff up and display, making them appear like much larger birds. ![]()
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