The Northern Cardinal is one of North America’s most recognizable and beloved birds, but many people misunderstand its nesting preferences. Unlike cavity-nesting birds such as bluebirds or wrens, the cardinal does not use traditional enclosed birdhouses with small entry holes. Providing a suitable structure requires moving away from the common birdhouse design toward a specialized open shelter. Cardinals will readily use an open-sided nesting shelf or platform, which offers the stability and protection they seek without enclosing them completely.
Cardinal Nesting Habits
Cardinals are classified as “open-cup” nesters, meaning they build their nests in the open, typically within the dense branches of shrubs, small trees, or thickets. This behavioral requirement is the fundamental reason they ignore traditional birdhouses. Their nests are usually situated in the fork of a branch or a dense cluster of foliage, providing concealment from predators and shelter from the elements.
The female cardinal is primarily responsible for constructing the nest, which usually takes between three and nine days to complete. She weaves together four layers of material, starting with a coarse base of twigs and bark, followed by a leafy mat, then a lining of grapevine bark, and finally a soft inner cup of fine grasses and pine needles. This final cup is typically small, measuring about four inches wide and two to three inches high, requiring a secure, wide, and stable base for support.
They tend to build their nests between 3 and 15 feet off the ground, often choosing dense cover that is available year-round, like evergreen trees and shrubs. Cardinals are non-migratory and may have multiple broods per breeding season, but they rarely reuse a nest from a previous attempt. Providing multiple nesting options is beneficial since they rarely reuse old nests.
Designing the Ideal Cardinal Nesting Platform
Since cardinals are open-cup nesters, the appropriate man-made structure is a nesting shelf or platform. This design provides an open front with a sturdy roof and three partial sides, prioritizing stability, openness, and protection from rain and sun. The floor should offer a stable base, with ideal dimensions ranging from 7 to 8 inches deep and 8 inches wide.
To contain the nest materials, the platform should include a low front lip, typically 1 to 2 inches high. The structure must feature a substantial roof that overhangs the nesting surface by at least 4 inches to shield the nest from precipitation and direct sunlight. The sides of the structure should be about 6 inches high to provide a sense of enclosure without creating a fully enclosed box.
Untreated wood, such as cedar or pine, is the best material for construction, as it is naturally weather-resistant and lacks chemicals that could deter the birds. Any finish, such as paint or varnish, should be avoided on the interior surfaces, as the lingering odor can cause the cardinals to abandon the site. Drainage holes should be drilled into the floor of the platform to prevent water from pooling and soaking the nest material.
Strategic Placement for Successful Nesting
The placement of the nesting platform is as important as its design for attracting cardinals. The structure should be mounted at a height that mirrors their natural nesting range, generally 5 to 15 feet above the ground. Placing the platform within this range helps to deter ground predators while remaining accessible to the birds.
It is necessary to install the platform near dense, protective cover, such as thick shrubs, vines, or evergreen thickets. Cardinals feel most secure when the nest is concealed, so the structure should be mounted on a sturdy surface like a tree trunk, fence, or wall that is within a few feet of this dense foliage. Mounting the platform to face away from prevailing winds and heavy rain is also recommended to maximize the shelter provided by the roof and three walls.
To protect the nest from climbing predators like snakes and raccoons, a baffle or predator guard should be installed on the pole or post supporting the platform. The platform should be placed in a relatively quiet and semi-secluded area of the yard, as cardinals are shy and will avoid areas with excessive human or pet traffic. Offering multiple platforms at different heights and locations can increase the likelihood that a pair will select one for successive nesting attempts.