Bird Houses

By Jeff Berti
A small investment of lumber, nails and a little elbow grease to build bird houses can double as an activity to cure the winter blues and provide bird-watching enjoyment throughout the spring and summer.
Missouri has 26 species of cavity nesters, or birds that nest inside a hole in a tree trunk or limb. These birds, which include bluebirds, warblers, wrens, chickadees and tufted titmice, will readily use nest boxes. If you live in an urban area or along a stream where many of the old or dead trees have been removed, you should put up bird houses to attract birds that you can enjoy watching throughout their nesting period.
Building or refurbishing bird houses now will ensure they are “open for business” when birds arrive this spring.
To provide nesting habitat for the early birds of spring, put up houses for purple martins. The largest of the swallows, purple martins are named for the glossy bluish-purple appearance of adult males. The first males to arrive are called “scouts.” They appear in southern Missouri around mid-March and usually reach Grundy County by April 1.
Although martins historically nested in rock crevices and hollow trees, the birds have adapted to houses provided by humans and now depend almost entirely on them. One way to attract nesting martins is to suspend several gourds from cross-pieces on a pole. The most common purple martin house is the apartment-style box. Instructions to create both types of houses are included in the Missouri Department of Conservation booklet “Missouri’s Purple Martins.”
Missouri’s state bird, the Eastern bluebird, lays eggs as early as April 1, so January is a good month to put out birdhouses for them. Bluebird nest boxes can get a lot of use as bluebirds sometimes raise three broods a year.
Knowing where to place a bird house is as important as knowing when to put one up. Cats and other predators should always be considered when putting up houses. When young birds first leave the nest they are going to hit the ground. If a nest box is placed where there is no cover, the birds will be easy prey. When putting up bird houses, try to place them in areas where thick vegetation or shrubs grow. If the house is in your yard, let the grass beneath it grow tall for added cover. If tall grass is undesirable, try planting some taller flower varieties under the house. This will not only provide cover, it will also attract a variety of bugs, which is food for many bird species.
Placement also can help determine the species attracted to a bird house. Houses designed for bluebirds often are used by other birds when placed in habitat undesirable to bluebirds. Bluebird houses should be placed 4 to 6 feet above the ground on a pole, with the entrance facing the nearest large tree. A bluebird house placed 10 to 15 feet above the ground in a wooded area may be used by wrens, chickadees, titmice or even flying squirrels. The same house placed on a pole or in a dead tree could get tree swallows or prothonotary warblers as occupants. Remember to space the bird houses out. Most birds are territorial, so several houses in the same location will be a waste of time. Bluebirds, for instance, need at least 100 yards between houses in order to compensate for the birds’ home range.
Twigs and other old nest material can harbor parasites that plague young birds, so remove the old nest between broods. When cleaning out a nest, removal of the nesting material is sufficient. Cleaning the house with household cleaners may harm the birds or cause them to quit using the box. If you are building your own birdhouses, always remember to put a hinged lid on it for easy cleaning.
The Missouri Department of Conservation booklet “Woodworking for Wildlife” has easy-to-follow instructions for building, installing and maintaining houses for a variety of birds. For a copy of the booklet, you can log on to the Department of Conservation’s website at www.mdc.mo.gov. With the number of woodworking projects in the book, your winter doldrums will be a thing of the past.