In previous blogs, we’ve focused on the impact of local invasive species in the Chicago area. But how is the bird community impacted? To get a better sense of how the bird community is affected by non-native species, we reached out to our friends at the Chicago Ornithological Society and spoke to Society President Edward Warden.
How did some species of bird become invasive?
There are a couple of species of bird considered invasive in Chicago. The biggest way we get invasive birds is by introducing birds from other parts of the world where they are native, to our ecosystem where they are not. Birds like the European starling, house sparrow, house finch, and rock pigeon were all brought here by people on purpose and have gone on to become invasive in many parts of the country.
For a variety of reasons, these birds have the perfect combination of behavior, needs, and adaptations to succeed more than other birds. Changes we’ve made to our local environment often help invasive birds to be even more successful.
What does the presence of an invasive bird species mean to an ecosystem?
The biggest problem that invasive birds present is competition with native birds. Starlings and house sparrows in particular are very aggressive and will often steal food and nesting places from other birds. Native birds already face many challenges, so adding an invasive bird to the list can cause native birds to start to disappear. If we lose enough of our native birds, we start to see other parts of the ecosystem, from plants to insects, get thrown off balance.
Not all invasive birds harm the environment or other birds. Some seem to show up, do very well, and still play nice with others. Additionally, having the invasive birds around can benefit some species. A great example is the rock pigeon, which provides a lot of food for the native peregrine falcon.
Are invasive birds easier or more difficult to manage than other invasive animals (mammal, fish, insect, etc)?
Invasive birds can be a challenge to manage because they can fly great distances very quickly. It doesn’t take long at all for birds to make their way across cities, states, and even the country looking for a good place to settle down. However, birds are very easy to see and hear which makes it easier to track where they go and manage their numbers and impact.
Is there an invasive bird species in Illinois that is specifically concerning due to its impact on native species or other factors?
The two most concerning invasive birds in Illinois are house sparrows and European starlings. Both are aggressive and can harm local bird populations by stealing food, nesting spaces, and compete for other resources. Starlings are also a big problem for people as well as they can cause expensive damage to farm crops. Today, however, both are under enough control that they are no longer spreading, and in some cases, are slowly declining.
Is there any way that individuals can help native birds prosper in our area?
There are lots of ways to help native birds! The biggest one is to plant native plants. Whether it’s planting a tree on your street or native flowers in your yard, native plants create the shelter and food that birds need.
Additionally, if you have room, put up a bird feeder and bird bath to give local birds a boost. Winter birds need food to keep warm, spring and autumn birds need the food to fuel their epic migrations, and summer birds need the food to feed their young. If you keep feeders up year-round, you will see different birds each season visit for a snack.
Lastly, help protect and care for your local park. Whether it’s picking up trash or helping plant trees and native plants, volunteering at your local park ensures birds have a place to go for food, to rest, and to lay eggs.