Making birdhouses home sweet home

A few weeks ago, I received a question from a reader in Altavista, who wanted to know what type of birdhouses he should place in his yard to attract desirable species.

Having never seen the yard in question, I couldn’t really give him a meaningful reply. In fact, the habitat in which the house will be offered is much more important than the type of structure.

Of course, the term “desirable species” is also something that needs a little explanation. In my mind, any native bird is acceptable, and most of the aliens are not. We do not want to do anything that would encourage either the house sparrow or starling, since both species are destructive to many of our cavity nesting birds.

Most of the birds with which we are familiar do not use birdhouses. There is no point in putting up a nice box and waiting for a cardinal, mockingbird, indigo bunting, brown thrasher or goldfinch to move in and start raising a family. These species construct their nests in shrubs, trees or other vegetation.

Some birds, such as the robin or Carolina wren, may choose to place their nests on structures, such as barns, shelves or bridges, but only rarely enter a bird box and build a nest inside. In fact, the vast majority of the birds that breed here are not cavity dwellers.

However, some birds that we commonly see in our yards are among the approximately dozen species that will happily move into a bird box. Possible tenants include Carolina chickadee, tufted titmouse, white-breasted nuthatch, house wren, tree swallow and the ever-popular bluebird. If you want to attract purple martins, you will need a combination of the right environment, and specialized martin houses or gourds.

If you live in an urban area that provides little habitat for bluebirds but has a healthy population of house sparrows, then don’t put up any bird boxes. You will simply be assisting the house sparrows to raise big families, and this alien species is an alarmingly efficient killer of bluebirds. If the bird box’s entrance hole is 1½ inches or smaller, starlings will be excluded.

Assuming you have the proper habitat and the potential of attracting native species, it is important to remember that putting up a bird box is not the end of the story. As “landlord,” you need to maintain the box, clean out the old nesting material after the babies have fledged and, if necessary, install a predator guard. Folk wisdom says the bluebird chooses a sweetheart on Valentine’s Day, so if you have the right conditions, put out a box and get ready for spring.

News and notes

Randolph College will host a program Feb. 19 to celebrate the 200th anniversary of Charles Darwin’s birth. It will begin at 7:30 p.m. in Room 315 of Martin Science Hall, with speakers who focus on his impact.

The Virginia Society of Ornithology is sponsoring a field trip to the Outer Banks Feb. 20 through 22, with visits to the Pea Island National Wildlife Refuge and Cape Hatteras National Seashore. Trip headquarters will be the Clarion Inn in Nags Head.