Many of the birdhouses found along the Rouge’s hiking trails were originally built to create homes for eastern bluebirds. Today, many other bird species also use these houses, including tree swallows, house wrens, and house sparrows.
You may have noticed some “double-decker” birdhouses around the park. These are also designed to provide nesting sites for eastern bluebirds. Single birdhouses are often taken over by more aggressive species such as house sparrows, who can out-compete bluebirds for territory. These aggressive birds will not share space with their own species but will tolerate neighbours of a different species. With “double-decker” birdhouses, house sparrows may occupy the first unit, but the second unit is left free for less aggressive species like the eastern bluebird.
A birdhouse made specifically for purple martins has been set up beside the Parks Canada welcome area by Zoo Road, near the Toronto Zoo area of the park. Purple martins are a species of swallow that is almost entirely dependent on human-made structures for habitat. Purple martin houses are set up on a long pole (up to 18 feet) and have multiple compartments to provide enough nesting space for a whole colony of birds. The field next to the welcome area is a perfect spot for the birdhouse, as purple martins prefer open areas not far from bodies of water. They are also not afraid of humans, allowing the house to be placed right beside the welcome area.