Birds in the garden are always a joy! What’s more, they are off in an estimable value to plants because of the great number of insects they consume.
One way to attract them to the garden is to provide them with boxes for nesting purposes. This, too, is the time to build these structures and set them up in readiness for the housekeeping of these delightful friends.
Man’s Association With Birds
Stretching back into antiquity is highlighted by the houses built in Asia Minor for the doves used to carry messages, the shelves for swallows put up in Japanese temples, and the nesting places and feeding towers maintained by the Brahmans of India.
Likewise, American Indians taught the colonists to attract colonies of purple martins to their gardens. So when you build a birdhouse, you are continuing one of man’s long-established traditions.
Under ordinary circumstances in the eastern United States, the average number of nesting birds is slightly over one pair per acre.
In experiments, however, that figure has been expanded in Golden Gate Park to 404 pairs in 40 acres, in Chevy Chase, Maryland, to 224 pairs in 23 acres, and in Olney, Illinois, to 70 pairs in eight acres.
Thus, in suburban areas, it is fairly easy to raise the bird population from one to 10 pairs by building bird boxes.
As a result of experiments, also, it is known that 50 species of birds in the United States will nest in boxes. Many of these are not suited to suburban gardens, for instance, the wood duck, owl, or sparrow hawk.
On the other hand, attracting bluebirds, tree swallows, house wrens, chickadees, robins, phoebes, and small woodpeckers is easy and delightful.
Requirements For Bird Boxes
There are several requirements for bird boxes. Nesting boxes must be durable, rainproof, cool, easily cleaned, and built to the recommended specifications of a particular species.
In these measurements, there is wide variation according to birds’ size and natural nesting habits.
Durability is best secured by building boxes from one-inch thick wood stock. The natural powers of insulation make it an excellent choice, whereas metal, pottery, or tar paper, as have been suggested, are inappropriate because of heat or impracticality.
Although cypress is the most durable wood, pine and yellow poplar are more readily available and easy to work with.
If a more rustic box is preferred, rough bark slabs, usually available at a small cost from a mill, can be used.
For chickadees and woodpeckers, houses having this more natural-appearing surface have a distinct advantage.
Some hardware is necessary, and brass is desirable because it does not rust. Screws are superior to nails, as general weathering will not force screws to loosen, as nails often do. A box strongly made from wood with brass hardware will render several years of use.
The nesting box should be as rainproof as possible. This is achieved by making tight joints and the roof slanting.
If nearly flat, a groove across on the underside of the roof front, one-half inch from the edge, will prevent water from working back into the box.
To prevent ice from forcing the sides from the bottom of the box, carry the sides down a half inch below the box floor. Small auger holes in the floor will provide drainage in case of driving rains.
Obtaining Coolness In Summer
Coolness in the summer heat may be obtained in two ways. Auger holes in the upper sides, just beneath the roof, aid air circulation. Or a one-eighth-inch opening can be left across the top front of the box, just beneath the roof.
This should not exceed one-eighth of an inch and so permit excessive exposure. A two to three-inch overhang of the roof in front gives further protection.
Inside The Nesting Box
To access the inside of the nesting box, the roof, or one of the sides, must be removable. Sometimes the roof has been made like a tightly fitting cover, but it can be blown off in the strong wind.
The most effective method is to place a hinge so that the front, or a side, can open down for easy cleaning. It can be made to stay shut by using a hook and screw eye.
Outside The Nesting Box
As to the outside, it can be painted, stained, or left its natural color. In any case, it should be painted with a wood preservative to ensure a long life.
If the paint is desired, the woodsy colors —green, brown, or gray — are most attractive to birds, though white paint on houses in full sunlight will reflect the heat and thus be cooler.
BlueBird Box Measurement
Measurements for the bluebird box are the same for the swallow, two of the most satisfying and easiest birds to attract. This box should have a 5 by 5 inches floor cavity and a depth of 8″ inches.
The entrance should be 6″ inches above the floor, and the diameter of the entrance hole should be 1 1/2″ inches.
Both birds prefer a sunny location, but the recommended heights above the ground are 5′ to 10′ feet for the bluebird and 10′ to 15′ feet for the swallow.
Certainly, you will want a wren house. It should have a four-by-four-inch floor, a 6 to 8-inch depth, and a one-to-one and one-fourth-inch entrance hole 4″ to 6″ inches above the floor. Place it 6′ to 10′ feet above the ground.
In Open Woodsy Areas
You may attract nesting chickadees if you have an open, woodsy area. A bird box’s object is to simulate the natural nesting conditions as nearly as possible.
Thus, the measurements for the chickadee box are floor space, four by four inches; depth of the cavity, eight by 10 inches, and above the floor, six to eight inches; diameter of the entrance, one and one-eighth inches; height above ground, six to 15 feet.
Attracting Hairy Woodpecker
In a similar lightly shaded area, you may wish to put up a house for a downy or a hairy woodpecker.
The differences in sizes of these birds are reflected in the box measurements. For the downy, use these:
- Floor, 4 by 4 inches
- Depth, 8″ to 10″ inches
- Entrance above the floor, 6″ to 8″ inches
- Hole one and one-fourth inches
- Height above ground, 6′ to 20′ feet.
The hairy woodpecker, the larger of the two, demands a box with a floor of six by six inches, a depth of the cavity of 12″ to 15″ inches, with an entrance above the floor of 9″ to 12″ inches.
The hole diameter should be 1 1/2″ inches, with a height above the ground of 12′ to 20′ feet.
In both instances, wood chips and a little soil should be provided at the bottom of the box to ensure it will be tenanted.
Nest on Open Shelves
Some birds, however, prefer to nest on open shelves. Among these are the robin, phoebe, barn swallow, and often the catbird and brown thrasher.
These shelves are of two kinds — those with a roof and one or more sides and those without either. These can be flat, with narrow edges, or a shallow V with edges.
Shelves For Robins
Shelves for robins should measure six by eight inches and be eight inches deep from the roof to the floor or from floor to cave if it is attached to a garage or building. The preferred height is 6′ to 15′ feet above the ground if it is attached to a tree.
This shelf will serve the needs of a robin, a catbird, or a brown thrasher. Similarly, a 6 by 6 inches shelf placed 6″ inches beneath the caves may bring a barn swallow or phoebe.
When placing boxes, it is well to leave at least 25′ feet between them. However, swallows will nest closer together, and different species will use the same area.
44659 by Barbara Elinore Hayden