The House Wren (Troglodytes aedon) is a small songbird with a wide distribution across North America. Known for its loud, bubbling song and characteristic tail-up posture, this adaptable species thrives in proximity to human activity. The House Wren is a common fixture in backyards, parks, and suburban areas, where it seeks out sheltered spaces to raise its young.
Understanding House Wren Habitat Preferences
House Wrens are classified as secondary cavity nesters, meaning they utilize existing holes rather than excavating their own. They seek out a variety of sheltered, enclosed locations, including old woodpecker holes and natural crevices found in tree snags.
Their adaptability makes them frequent users of man-made structures, which is how they earned their common name. They readily nest in birdhouses, mailboxes, flowerpots, old boots, or small openings in sheds and garages. Wrens prefer a small opening to deter predators and larger competing birds. For those hoping to attract them, an entrance hole diameter of 1.25 inches is ideal.
The Construction of the Nest Structure
The male House Wren is solely responsible for selecting and claiming the territory and potential nest sites. He initiates the process by stuffing multiple cavities within his territory with “dummy nests.” These initial nest attempts are dense piles composed almost entirely of small, stiff twigs.
The purpose of these twig piles is to claim the space and establish dominance over the cavity. When a female selects a site, she takes over the actual construction of the nest cup. She lines the inner cavity with softer materials to create a protective cup for the eggs. This lining typically consists of feathers, grasses, hair, plant fibers, and spider egg sacs.
Managing and Coexisting with Nesting Wrens
Homeowners can encourage House Wrens to nest in suitable locations by providing species-specific birdhouses. Mounting a box 5 to 10 feet off the ground near shrubs or woody vegetation is usually effective. The size of the entrance hole is important for attracting wrens while excluding larger competitors.
The House Wren is highly territorial and aggressive, often destroying the eggs or nestlings of other cavity-nesting species, such as bluebirds, to secure a nesting site. To minimize this conflict, place wren birdhouses at least 100 feet away from other nesting boxes.
If a wren begins nesting in an inconvenient spot, such as a barbecue grill or a hanging basket, you may gently deter them by temporarily blocking the opening or moving the object before the nesting season begins.
Once a female begins constructing the soft nest cup or lays eggs, the nest is considered active and is protected by the Migratory Bird Treaty Act (MBTA). Under this federal law, it is illegal to disturb, move, or destroy an active nest without a permit. If the nest is composed only of the male’s initial twig foundation, and no nest cup or eggs are present, it is permissible to remove it.