The Northern Cardinal (Cardinalis cardinalis), with its distinct red plumage and prominent crest, is a highly recognizable backyard bird across North America. Many people hoping to attract this species consider placing a birdhouse, but cardinals generally do not use standard enclosed nesting boxes. Their specific nesting behaviors make the typical wooden birdhouse structure incompatible with their reproductive strategy. Understanding their natural preferences helps bird enthusiasts encourage them to nest nearby.
Why Cardinals Avoid Enclosed Nest Boxes
Cardinals reject enclosed birdhouses because they are “open-cup nesters,” not “cavity nesters.” Cavity nesters, like bluebirds or chickadees, seek out hollows in trees or posts. Cardinals build their nests in the open, exposed to air and light, and avoid dark, confined spaces for breeding.
The instinctual need for a wide, open view is important for the cardinal pair. An enclosed box restricts visibility, preventing the female from easily scanning for predators while incubating eggs. Traditional birdhouses, with a single small entrance, also lack the quick escape routes cardinals prefer when a threat approaches. The open nature of their chosen nest site allows the highly territorial male to maintain a visible perch nearby to guard the area.
Preferred Natural Nesting Locations
Cardinals select nesting sites that offer dense concealment and structural support for their open-cup nests. They typically choose thickets, dense shrubs, vines, and low tree branches, often at the edge of wooded or shrubby areas. This placement, usually between 3 to 15 feet off the ground, provides protection from ground predators and cover from above.
The female cardinal is the primary builder, constructing a bulky, four-layered nest over three to nine days. The outer layer consists of coarse twigs and stems, followed by a mat of leaves and strips of bark for the cup. The inner lining, which holds the 2 to 5 eggs, is made of fine materials like grasses, rootlets, and pine needles, which she shapes by pressing her body into the structure. Favorite plant species include dogwood, hawthorn, rose bushes, and dense vine tangles like honeysuckle.
Providing Alternative Nesting Structures
Since standard birdhouses are ineffective, attracting cardinals involves mimicking their natural habitat requirements. The most direct approach is targeted landscaping, meaning planting native shrubs and trees that offer dense cover year-round. Evergreen trees and thick, thorny bushes like rose bushes or blackberry brambles are good choices because they offer persistent shelter and concealment.
Open Nesting Platforms
For those who wish to provide a structure, open nesting platforms or ledges are a more suitable alternative to enclosed houses. These structures are small, roofed shelves with at least one side completely open, satisfying the cardinal’s need for visibility and an easy exit.
A suitable platform should have a floor area of about 7 by 8 inches and be installed in a quiet, sheltered location, such as near dense foliage or beneath the eaves of a porch. Placement between 5 and 15 feet from the ground is recommended to maximize the chance of a pair utilizing the structure.