One of the birds that many people look for to signal the return of spring is the Eastern Bluebird. However, many Bluebirds over-winter in our area, which gives them the first pick of the best nesting areas come spring. At one time Bluebird numbers were declining across North America, but with the help of conservation efforts such as habitat protection and nesting boxes, Bluebird numbers are on the rise. As you drive through Kensington Metropark you will notice several bird nest boxes set on posts along the roadside. These bird houses have been placed in grassy areas to provide nesting habitat for Eastern Bluebirds. Other bird species will also use these boxes, such as the Black-Capped Chickadee and the Tree Swallow. One nuisance bird that may also use a Bluebird box is the House Sparrow. House Sparrows are an invasive species; therefore, nest boxes are monitored to prevent these aggressive birds from taking over a prime nesting site. More about Bluebirds and nest box plans can be found here. To hear Bluebird songs and calls click here.