More than two dozen North American birds will nest in birdhouses. If you are lucky, your yard may be chosen by some of them. Providing the right birdhouse for your backyard habitat increases your chances of playing host to a family of birds. Whether you are successful or not will depend on many factors, including what type of birds you are trying to attract, where you place the birdhouse, regular maintenance and how you deal with predators.
The following guidelines are important for every birdhouse, no matter which species you are trying to attract:
- A birdhouse must be the proper dimensions, have the correct size entrance hole and location for the type of bird that it will attract.
- Good ventilation and drainage is a must. A roof overhang will help keep the interior dry.
- It needs easy access for cleaning and inspecting the interior. The top or side should be hinged for entry without disturbing the nest.
- It should be made of nontoxic materials and the inside should not be painted or stained.
- A perch on the outside is not necessary; it may provide easy access for predators.
Bluebirds prefer birdhouses mounted four to five feet high on an old tree stump or fence post. The house should be 5 inches wide and 8-12 inches tall. The diameter of the entrance hole should be no more than an inch and a half across and it should be located about 6-10 inches from the bottom of the house. It may be necessary to use a metal guard on a wood post if cats, snakes or raccoons become a problem.
Robins prefer a nesting platform about 8 x 8 inches if the crotch of an old tree is not available. A spot 6 feet or higher under an overhang or in a shady tree will work. Robins line their nests with mud, so having a puddle near by will be a popular attraction.
Chickadees, Nuthatches and Titmice share similar habitats. They prefer a house in a wooded yard attached to a tree limb or trunk. It should be hung about 5-6 feet from the ground. The floor should be 4 x 4 inches and about 10 inches tall; the entrance hole should be no larger than 1 1/8 inch to exclude unwanted birds.
Wrens are not very picky birds, although a 1 by 2 inch slot located 4-6 inches from the bottom of the house may be easier for them to use than a round entrance hole. The male Wren will build several nests for the female to choose from, so hang multiple houses 5-10 feet up on a sunny tree limb. A small house with a 4 x 4-inch floor and 6-8 inches tall will be perfect. They are sociable birds and will not object to a location close to the house.
Purple Martins nest in groups, so they require a house with a minimum of four large rooms that are 6 or more inches on all sides. The entrance hole should be about an inch and a half from the floor and be about 2 ¼ inches across. Porches and railings will make the house more appealing. Since purple martin houses should be located 10 to 20 feet off the ground, telescoping poles make maintenance and inspection much easier and help to avoid damage to the nests.
Although birds may find your birdhouse anytime of the year, having it up in early spring when birds are beginning to search for a home increases the chance that yours will be inhabited. Don’t give up if you have already missed the optimal time, late arrivals need home too!
Putting you birdhouse in the right location is as important as choosing the right house. Some important guidelines for proper placement include:
- Try to face you birdhouse north or east to avoid overheating in the summer.
- Do not place birdhouses to close to bird feeders.
- Avoid putting more than one birdhouse in a tree, unless it is a very large tree.
- Use no more than four birdhouses for one species per acre.
- Keep about 100 yards between bluebird houses and 75 yards between swallow houses.
- Mounting your birdhouse on a metal pole will discourage predators.
- Have water and food available.
Watching out for your tenants is an important part of being a responsible bird landlord. Monitor your houses often and remove any unwanted guests like squirrels, mice, snakes or insects. If predators become a problem, install a protector guard to the house or pole to limit access. Clean out the nest after each family has left and it may be used again throughout the summer. After you have cleaned the birdhouses for the last time in the fall, you can leave your houses out all winter or store them until spring.