Keep Acton’s bluebirds thriving
These native birds are making a comeback but face a significant threat from invasive house sparrows.
Many of us delight in spotting bluebirds, with their orange chests, flash of blue wings, and soft calls, whether at Cousins Field, Heywood Meadow, October Farm Riverfront, or our gardens.
These native birds are making a comeback but face a significant threat from invasive house sparrows, which aggressively compete for nesting spots, often displacing bluebirds and tree swallows. In some cases, house sparrows will attack and kill native birds as they build their nests, destroy eggs, or kill chicks before they fledge.
What can you do to help? House sparrows are prolific, each pair raising up to four broods a season. In contrast, bluebirds typically raise two broods. If you spot house sparrows nesting nearby, it’s crucial to remove the nest before they lay eggs to help maintain the balance between native and non-native species.
House sparrows are not protected by the U.S. Migratory Bird Treaty Act, so removing their nests is legal. However, before taking action, ensure the nest is indeed that of house sparrows. These birds are stout, brown, and easily recognizable: the male has a black bib and a gray crown. Their nests tend to be messy and loosely constructed, with a basket shape made from dried grass, twigs, coarse vegetation, and even trash. In contrast, bluebird nests are neat, cup-shaped, and made of pine needles or fine grass.
If you have an open, grassy area, consider setting up a bluebird box — tree swallows may also use it. However, like adopting a puppy, a bluebird box requires regular attention and care. Allowing house sparrows to take over a box and hatch their eggs is worse than having no box at all.
Visit sialis.org or contact the Division of Natural Resources at [email protected] to learn more.
Delia Kaye
Keyes Road
Acton Natural Resources Director
