(Photo and story by Pam Hunt)

House Sparrows (Passer domesticus) don’t get a lot of love on this side of the Atlantic. They aren’t native to North America and can even be a threat to native cavity-nesting species like swallows and bluebirds. But across the pond, they are a beloved feature of farms, gardens, and towns, so well-liked that they were imported from Europe in the 1850s. From these and subsequent introductions, the species spread throughout the conterminous United States and southern Canada. While House Sparrows occupy a wide native range across Europe, North Africa, and Asia, their non-native range is at least as large: encompassing most of the Americas, Africa south of the Sahara, eastern Australia, and numerous oceanic islands. Closer to home, it didn’t take long for House Sparrows to reach New Hampshire. They first showed up in the 1860s, probably because of nearly supplementary introductions in Boston and southern Maine.

The sparrow’s global success was facilitated by its adaptation to human-altered landscapes, with both urban and agricultural areas providing a wealth of food and nest sites. By the early decades of the 20th century, however, populations had started to decline, including in the native European range. The early phase of this decline has been widely attributed to the replacement of horses by the automobile, with a resultant loss of abundant spilled grain. More recent factors include declines in farmland and changes to agricultural practices, including more intensive use of pesticides. And because House Sparrows are social birds, there is even speculation that declines accelerated as there were fewer sparrows to congregate together. Declines in England have been extreme enough that House Sparrows are now a conservation priority there.

Although populations are in long-term decline on this side of the Atlantic as well (Figure 1), we don’t share Europeans’ concerns. As an introduced species, House Sparrows have had detrimental effects on native birds, particularly those that nest in cavities. Sparrows will evict bluebirds and Purple Martins from nest boxes and even take over the hollow mud nests built by Cliff Swallows. Sometimes they’ll even kill young they find in nests. As a result, people who maintain man-made housing for these birds actively remove sparrow nest when they find them. This is not feasible for largely inaccessible Cliff Swallow nests, and House Sparrow remains an important treat to that species where swallow populations are small.

In city centers and most farms (i.e., those without Cliff Swallows), where their threats to native birds are minimal, House Sparrows are rarely much of a problem. Their “cheerful” chirping may be one of the few signs of avian life for residents of many urban areas, and we shouldn’t discount the possibility of them being “gateway birds” to a greater appreciation of the natural world. It’s also possible that House Sparrows are something of a “canary in a coal mine.” If a species so well adapted to living alongside people is in decline, it might be sign of some important environmental issue that we haven’t identified. Pesticides in particular are of growing concern. While neonicotinoids, the dominant insecticides in use today, have long been touted as safe for non-target organisms, more and more studies are showing negative effects on birds. If an invasive species is being impacted by these chemicals, it’s reasonable to assume native ones are also sensitive.

State of the Birds at a Glance:

• Habitat: Developed areas
• Migration: Resident
• Population trend: Strongly decreasing
• Threats: Pesticides, cats, collisions
• Conservation actions: None identified

More information on “The State of New Hampshire’s Birds” is available here. Full species profiles in the format of “Bird of the Month” are now available here.

You can help collect valuable data on House Sparrows and other winter birds by participating in NH Audubon’s “Backyard Winter Bird Survey.” The survey will occur on February 8-9, 2025. Visit the Backyard Winter Bird Survey webpage for details.