While not everybody will accept your invitation to stick around, there are nearly 50 American bird species willing to nest in artificial houses intended for that purpose. Like any house guest, some are less picky than others. Birds will decide to stay and build a nest or move on depending on a wide variety of factors, such as the depth, overhang, size of the perch outside and diameter of the entrance hole. While no bird house will satisfy every species, there are a few designs that are more versatile than others.
Some birds prefer the open air to a boxed-in enclosure. These birds would adore a nesting shelf, which is basically a bird box with three walls missing. A hanging platform approximately 8 inches by 8 inches, topped with an angled roof that protects the full platform, is the only protection these birds require to build their nests. Birds that will use a nesting shelf include American robins and barn swallows.
Purple Martin Hotel
One of the most exacting birds to accommodate is the purple martin. Their house must be away from any possible sources of interference, such as trees or telephone poles. The entrance has to be a little more than 2 inches in diameter. Too narrow and they won't fit. Too wide and they'll be too skittish about predators and never set up shop. Birdhouses for purple martins are typically of the hotel variety, with around eight separate compartments, since purple martins insist on bringing all of their friends. While building and installing a purple martin hotel can be a pain, once a group of birds has taken up residence, they are likely to return year after year.
The most traditional of all birdhouses, the A-Frame has an angled roof, four walls, a single hole for entry, and a perch. Variations on the A-Frame will determine what kind of bird will be willing to live inside of it. An entrance hole about 1 and 1/2 inches in diameter, without an exterior perch, may attract blue birds. Woodpeckers prefer their entrances about 2 inches in diameter and will occasionally chip away at a narrow entrance until it suits their needs. Any birdhouse with an entrance greater than 1 and 1/4 inches in diameter will attract house sparrows, who are not very picky but are quite common. If you prefer to keep out sparrows, consider making your entrance 1 and 1/8 inches, which will accommodate chickadees and wrens.
Article Written By Louie Doverspike
Based in Seattle, Louie Doverspike has been a professional writer since 2004. His work has appeared in various publications, including "AntiqueWeek" magazine, the "Prague Post" and "Seattle Represent!" Doverspike holds a Bachelor of Arts in English from Hamilton College.