Building a birdhouse can be a satisfying early spring project, one particularly well suited to an adult and a child working together. The lessons are many: a bit of carpentry, ornithology and ecology. And so are the rewards, among them the sense of accomplishment that comes in building something with your own hands.
”People get out of it the benefits of having birds nesting near them, the satisfaction of seeing the nesting cycle of birds and knowing that they`ve helped boost the bird population in the neighborhood,” said Dr. Stephen W. Kress, the author of ”The Audubon Society Guide to Attracting Birds”
(Scribner`s, $24.95).
For the birds, the benefits are more direct.
”There`s a housing shortage out there,” said Lillian Stokes, who with her husband, Donald, wrote ”The Complete Birdhouse Book” (Little, Brown, $9.95) and ”The Bluebird Book,” to be published in April by Little, Brown.
”Every time a shopping center is built, there are fewer places for birds to nest.”
The skills and tools needed for birdhouse building are minimal, and the cost is low: as little as $6 for materials. Kits are also available, and the details given here can help in looking for a ready-built house.
Pick a species
The first step is to decide which birds you want to attract.
”It`s a common misconception that all birds will nest in a house,”
Donald Stokes said. But if a species will nest in a cavity-say, a hollowed-out limb of a dead tree-it usually will use a birdhouse, or nesting box, as many ornithologists like to call it.
”The place to start is to realize that boxes need to be designed for a specific bird,” said Todd A. Culver, education specialist at the Cornell Laboratory of Ornithology in Ithaca, N.Y. ”And that`s the problem with a lot of what`s on the market: they`re designed to attract humans, not birds.”
The next step involves a bit of research and the process of elimination:
finding out which species nest in your area, which will use birdhouses and which probably will find your property, whether city garden or sprawling farm, an attractive nesting site.
”With a list of cavity-nesting species, if you look at their habitats, you will probably have a couple of choices,” Culver said.
Having narrowed the field, choose a species and tailor the dimensions of your house accordingly. Houses can be put up-stationary mounting is preferable-between late February and early July.
Specifications and plans are included in the books by Kress and the Stokeses, and the Cornell lab can provide a free list of species, habitats, nest-box dimensions and heights at which the houses should be mounted.
Only simple hand tools are needed: a saw, claw hammer or screwdriver, and a brace with an adjustable bit or an electric drill with eighth- and quarter- inch bits to make nail and ventilation holes and a wider bit for the entrance hole. You will also need about two dozen galvanized steel six- or eight-penny finishing nails or the same number of thin wood screws, from 1 1/4 to 1 1/2 inch long.
The `super easy` model
In ”The Complete Birdhouse Book,” the Stokeses offer plans for what they call a ”super easy” house, a simple flat-topped box that can be cut from two boards. One side of the house pivots on two nails, so it can be opened for cleaning. It is held in place by an L-shaped hook or screw eye.
What sort of lumber should you use? There seems to be a consensus that rough-sawn cedar is ideal, but it can be hard to find. So the Stokeses recommend three-quarter-inch common pine, and Culver suggests pine or fir.
These guidelines can help insure success:
– Ventilation and drainage are important. For a house with a small-diameter entrance, at least two quarter-inch holes in each side will help provide cross-ventilation. Trimming off the corners of the bottom panel will assure drainage. For a flat-roofed house, two shallow rain grooves running from side to side will help keep water out.
– Do not add a perch below the entrance hole; it can provide a platform for such nest competitors as starlings.
– To discourage raccoons from removing eggs or nestlings from the house, add to the entrance hole: drill a hole the same size as the entrance in a three-quarter-inch block of wood, and attach it to the house.
– If you use smooth wood, provide the fledglings with a pathway out of the house. With a saw or knife, score the inside front wall with at least three horizontal grooves leading up to the entrance.
”Without that, it`s like trying to climb up a pane of glass,” said Marc D. Koolen, who teaches in the biology department at Phillips Academy in Andover, Mass., and who builds birdhouses for the Massachusetts Audubon Shop and Nature Co.`s 51 stores.
– The more weathered the house, the better birds seem to like it, so do not use any wood preservatives. This also protects the birds from chemical exposure.
– A good guidebook can be invaluable in dealing with specific problems, particularly predators and parasites. For example, to minimize the danger of blowfly larvae, particularly in bluebird and wren houses, Kress suggested making a simple inch-high nest platform out of three-eighths-inch hardware cloth (wire mesh). The larvae will fall through the platform, away from the nest.
– Clean out the house after each nesting and again in late winter, checking for parasites.
