Attracting bluebirds requires a precise installation strategy that considers both vertical placement and surrounding habitat. Proper mounting and protection ensure the bluebird house functions as a secure cavity, offering protection against predators and harsh weather. Thoughtful placement allows the birds easy access to successfully raise their young in an environment mimicking natural cavities.
Optimal Mounting Height
The recommended height for mounting a bluebird house is generally between four and six feet from the ground, measured to the bottom of the box or the entrance hole. This height is a strategic compromise, deterring common ground predators while allowing for easy human monitoring and maintenance. Mounting the box too low, such as on a short garden stake, makes it highly vulnerable to climbing mammals like raccoons, skunks, and house cats.
The house should be affixed to a smooth, round metal pole rather than a tree or a wooden post. Unlike a rough wooden surface, a smooth pole is difficult for climbing predators to grip, limiting their access to the nest. The four to six-foot range is favored because it balances security with accessibility, allowing caretakers to quickly check the nest’s progress without needing a ladder.
Site Selection and Habitat Requirements
Bluebirds prefer open, grassy areas where they can easily spot and forage for insects, making habitat a determining factor in nest box occupancy. Ideal locations include pastures, large lawns, orchards, and the edges of golf courses, which provide clear flight paths and an abundance of low vegetation. The house should be positioned away from dense woods or heavy brush, as these areas favor competitors like House Wrens and provide cover for predators.
The entrance hole should often be directed toward an open field or a scattered tree within 25 to 100 feet, offering a safe landing spot for newly fledged young. If installing multiple bluebird houses, they must be spaced far apart due to the species’ territorial nature. A minimum distance of 100 yards (300 feet) is required between boxes for Eastern and Western Bluebirds to prevent aggressive competition.
Predator Protection Systems
To ensure nesting success, the mounting pole must be equipped with a specialized predator defense system to stop climbing animals. The most effective method is a stovepipe or cylindrical baffle, which is a smooth, metal tube typically 24 inches long and at least 8 inches in diameter. This baffle is mounted directly below the nest box, positioned so the top is at least four feet off the ground and can wobble freely when touched.
The stovepipe baffle prevents raccoons, snakes, and squirrels from gaining purchase on the pole and reaching the nest. For additional protection against persistent climbing predators, the pole itself can be lightly coated with carnauba wax or a similar slick substance. In areas with aggressive European Starlings, a specialized entrance hole guard can also be used to prevent them from entering and destroying the bluebird nest.