House Sparrows are very common in the United States, especially in cities and towns. They’re easy to find near buildings, barns, and other centers of human activity.
But are they an invasive species?
House Sparrows are an invasive species in most of the world, posing a threat to native birds they compete with for food and nesting space. They are native to Europe, and they were first introduced to the United States in Brooklyn, New York, in 1851.
Why House Sparrows Are an Invasive Species
House Sparrows are considered an invasive species because they were introduced to new areas where they weren’t native and then started to outcompete native bird species.
They now inhabit all of North and South America, Africa, Europe, Australia, and New Zealand.
What Is an Invasive Species?
Invasive species are non-native species that reproduce so quickly and effectively in their new environment that they drown out or stifle the development of native species.
They sometimes do this by depleting other species’ food sources, while other times, they prey upon native species to an extreme degree.
The Natural Range of the House Sparrow vs. Where They Live Now
House Sparrows are native to Europe and Northern Africa but have since been introduced to South Africa, North and South America, Australia, and New Zealand.
House Sparrows were introduced to the United States through Brooklyn, New York in 1851 when 100 birds were released into the wild to control insect populations and reduce the new residents’ feelings of homesickness.
Since then, House Sparrows have expanded their range to encompass the entire United States.
Impacts of House Sparrows on Native Populations
The Cornell Lab of Ornithology recently launched a citizen science project called The Birdhouse Network to monitor the impact that House Sparrows and other invasive species have on native birds.
The lab found that House Sparrows comprised 43% of the group of competitor birds taking nesting boxes from native species.
This means that House Sparrows have been preventing native birds from using nest boxes on a large scale, making it harder for them to find safe spaces to lay eggs and raise young.
House sparrows are quite aggressive in how they go after nests, and will even attack and kill native birds to steal their nests.
How To Reduce the Impact of Invasive Species Like the House Sparrow
Keeping House Sparrow populations under control gives native species a chance to propagate, ultimately leading to healthier ecosystems.
Thankfully, there are several humane ways to do this.
Deterring House Sparrows From Nesting
You can take several steps to prevent House Sparrows from taking over your yard and your nest boxes.
One way to deter House Sparrows is to avoid using certain foods in your feeders, namely filler grain like cracked corn or millet.
These foods attract House Sparrows more than other birds, and they will follow their favorite foods.
Another way to deter House Sparrows is to place nest boxes in isolated areas, as House Sparrows tend to flock to areas with heavy human traffic.
Ideally, your nest boxes should be closer to forested areas than they are to houses and other buildings.
House sparrows are not a protected species in the United States, and so physically removing House Sparrow nests or eggs from nest boxes is also a legal option.
However, most conservationists will not remove bird nests unless they have significant experience and can do so with precision and care.
Supporting Native Birds
Nesting places and food sources have become increasingly scarce for North American birds.
Because of this, the impact of non-native bird species on natives has been even more of a threat.
By supporting these birds with food, water, and shelter, you can make resources less scarce and reduce the impacts of competition.
What Do Native Birds Eat?
Native birds eat a wide range of food, from seeds to fruits to insects. The best way to support them is to plant trees and shrubs that provide all these food sources.
That said, offering additional food sources through feeders is also helpful for native birds.
Consider offering high-fat seeds and suet, as well as nectar and tree nuts.
Make sure that you offer supplemental food consistently across all seasons, as birds need the support year-round.
Providing Shelter for Native Birds
In addition to providing food, native plants can provide valuable shelter for native birds.
By planting native trees, shrubs, and flowers, you can make it more likely that birds will find a place to live in your yard and deescalate the competition between birds.
Native plants provide both a place to take cover from predators and a place to lay eggs, meaning that adult birds can thrive and raise the next generation in peace when they’re present.
To increase the amount of available bird shelter in your yard, create a brush pile for birds to hide in, and leave things like tree snags and mud spots alone.
Birds use both dead trees and mud for nesting purposes, and so keeping these natural features in your yard can make it easier for them to thrive.
Nesting boxes are also valuable for birds because they provide a safe place to raise young.
When choosing a nesting box, make sure that you find one with untreated, natural wood.
The box should also have a hole big enough for small birds to get in, but not so large that predators can reach the nest.
Using a predator baffle to keep snakes and other creatures from accessing the nest is also a good idea.
Nesting boxes allow conservationists to monitor the development of bird species, which is another reason why they’re so valuable.
Nesting box doors allow you to watch nestlings develop, and they allow you to remove the nests of invasive species if you wish.
For more on when or where to set up a nesting box for native birds, see this guide from the National Wildlife Federation.