Building For Backyard Wildlife

PROVIDING birdhouses and shelves can be a fun and rewarding part of a wildlife program. It doesn’t matter where you live– in an apartment, townhouse or single-family dwelling– in a town, a suburb or the country–you can attract birds by providing the proper nesting structure.

Birds such as Black-capped Chickadees, Purple Martins or bluebirds are cavity nesters and benefit from bird houses. Other birds like the American Robin and the Barn Swallow will use open nesting structures.

A well-built house that is durable, rainproof, cool and easy to clean can add to the attractiveness of your property. This winter just might be the perfect time to start your woodworking project and build a birdhouse. It is an excellent activity to do with a youngster, possibly working it into a 4-H woodworking project.

What do you need?
Birdhouses and shelves can be constructed from a wide variety of materials including wood, PVC pipe or natural items such as gourds. Gourds are easy to grow, are lightweight, and make an attractive addition to a backyard.

Avoid using metal for birdhouse construction because it tends to overheat. The exception is the Purple Martin house, which is usually made of lightweight aluminum to make raising and lowering the apartment complex easier.

Any good, solid, untreated wood is generally the best construction material. Cedar, pine or poplar are particularly easy to work with and weather well. Cedar is durable and its naturally occurring aroma may discourage parasites inside the birdhouse. One-inch boards, which actually measure about three-quarters of an inch, provide sufficient insulation and are widely available. Reusing scrap wood from other building projects can save money and cut down on waste.

Galvanized or aluminum nails or screws are preferable because they don’t rust, and nails with roughened shanks (designed to hold tightly) are better than smooth nails. Galvanized siding nails, 12-1/2 or 14 gauge and 1-1/2 to 1-3/4 inches long, work well and are readily available. Screws are probably best of all. To prevent injuries to occupants from sharp points, make sure there are no nails protruding into the box cavity.

To paint or not to paint?
Birdhouses and shelves, especially those made of durable, long-lasting cedar, don’t need to be painted. Exterior paint, however, will prolong the life of a bird house or shelf made of less durable pine or poplar.

Exterior latex is generally recommended. If colors are used, natural tones such as light brown, gray, or dull green are usually best. Because they are placed in exposed locations, martin houses are an exception: they should be painted white to reflect heat. Do not paint the interior of the nest box or the entrance hole.

Drainage and ventilation
Drilling a few small holes in the floor of the birdhouse allows proper drainage. Leaving half-inch gaps under the eaves or drilling several holes of 1/4 to 5/16 inches along the top of the sides provides adequate ventilation.

Birds can be particular about the entrance hole size, so measurements should be fairly exact. Also, properly-sized entrance holes may keep out unwanted species.Avoid perches at the entrance hole because birds don’t need them and perches make handy grips for would-be nest predators.

In the Midwest, facing the entrance hole in a southeasterly to northeasterly direction may help prevent chilling from cold spring rains. Recent studies indicate that bluebird nest boxes may have the greatest nesting success when the entrance hole faces the northeast, apparently because of warming by early morning sun.

Exit stairway
Roughen the inside portion of the hole just below the entrance so young birds can climb out of the house easily. This can be done by sawing grooves an eighth of an inch deep or by punching dents in the wood with a screwdriver.

Houses need an access door that allows easy inspection with minimum disturbance to occupants. One of the sides can be made to swivel out for side access, or hinges can be placed on the top.

Clean nest boxes and shelves are more likely to be occupied. Proper sanitation improves the chances of a healthy and successful brood. Nest boxes and shelves should be cleaned prior to each nesting season and immediately after any broods have left the box, even if the adult birds show signs of re-nesting. Old nesting material, eggs and dead nestlings should be removed from the box or shelf to keep parasites down. A nearby birdbath with clean water and a place for sand or dust baths also will aid in discouraging parasites.

Maintenance and monitoring
Wood duck, American Kestrel and bluebird houses should be ready for occupants by March and most other boxes and shelves should be ready by April.Birdhouses and shelves should be accessible so you can check and clean them when needed. Part of being a responsible landlord is taking care of tenants. Monitor birdhouses and shelves once a week to prevent nuisance or non-native species (House Sparrows or European Starlings) from taking over. If you clean out nest boxes after each brood has fledged, the box may be used again throughout the summer.

In planning access to boxes, consider that Purple Martin houses made of wood may be too heavy to mount on telescoping poles, a pole often used with aluminum martin houses or gourds. An alternative is to mount a wooden martin house on a fixed shortened pole and then inspect it using a ladder.

In the fall, after you have cleaned out the boxes for the last time, you can leave the boxes up for shelter during the winter. Prevent access to the box by plugging the entrance hole or put them in storage. Squirrels may gnaw to enlarge the entrance holes of boxes left outside.

Gourds will last longer if they are stored inside during the winter. –Grand Island