There was a time when cavity-nesting birds like bluebirds or chickadees could find a natural cavity without problem. Woodpeckers did the work for everyone. Today, nesting cavities are hard to find. Nest boxes — bird houses — help fill that natural habitat gap.
Spring is nesting time, but if you want boxes in your yard or elsewhere, fall is a good time for the project. The birds likely to use the box — bluebirds, tree swallows, house wrens, and black-capped chickadees — likely will appear before the ground has thawed enough to accept a mounting post.
Birds by instinct make particular choices in nesting sites, for good reason. Given short lives on average, many small songbirds — the perching birds, also known as passerines — probably get no more than one or two nesting opportunities in their lifetimes. Success is critical.
Nest boxes look simple, but there are important basics to consider.
Choose a wooden box (cedar is good), or a round PVC box. The box is best unpainted, outside or in. Choose practical over cute.
The box should be tightly built, best assembled with screws. Important: the box must be readily opened. You will open the box many times in its lifetime. If you must use any tool other than your hands to do this, you have chosen a bad box.
The front panel should swing down to open rather than up. It gives you a better look inside. Why look inside? To see what's going on. The birds won't mind.
Knowing what's happening in there is much of the pleasure the box and its occupants can bring you. But views should be quick and days apart.
