Why Do Bluebirds Need Our Help?

Between the 1920s and the 1970s, the Bluebird population declined by an estimated 90%. There are several reasons for this but the main ones are loss of habitat and competition from other species.

Loss of Habitat

The Bluebird is a cavity-nesting bird, which means it prefers to build its nest in a tree cavity. Unlike the woodpecker, however, the bluebird’s beak is not suited for excavating. It depends on natural cavities or ones made by other birds. However, the expansion of large commercial or agricultural operations, the growth of cities, and dense residential land development have destroyed many of the bluebirds’ natural nesting places.


The main source of competition for Bluebirds is a bird that is not native to North America – the House or English Sparrow. The House Sparrow was introduced to this country in the mid-1800s. It was thought that this bird would help control insect pests; however, those that brought them here seriously underestimated this bird’s fiercely competitive nature. The House Sparrow population exploded, while that of the Bluebird dropped precipitously declined. While House Sparrows will nest about anywhere, they can find a nook or cranny, they compete with the more finicky Bluebird, and will often drive away adult Bluebirds, leaving the nestlings to starve to death. Worse, they will also peck open unhatched Bluebird eggs and kill the babies, or even adults they happen to find sitting in the nest. They have even been known to build their own nests on top of the bodies of the Bluebirds they have killed. Another source of competition for the Bluebird is the Eastern Starling, a bird that is equally aggressive and will also kill both Bluebird adults and young.