Hillary Nelson David Petty

Related Articles

Human beings aren’t the only creatures on the planet to catch spring fever. As the days grow longer, birds, too, are bursting with energy: singing their hearts out, pairing off and searching out good nest sites. If you’d like to invite a bird family to make a home in your back yard, try rolling out the welcome mat by building a simple nest box for them.

Cavity Nesters
Only certain birds, the so-called “cavity nesters,” will rear their chicks in birdhouses. This is because cavity nesters are genetically programmed to use decaying wood as a nesting site. Such birds find man-made nest boxes a good substitute for an old snag or rotted fence post.

Nest Boxes to the Rescue
Luckily, most cavity nesters will happily move into man-made birdhouses as long as they are properly designed and located near access to food, water and appropriate habitat. In the last few decades, many thousands of nest boxes have gone up all across the nation. “Bluebird trails”—nest boxes mounted on poles in open fields—have proved a great success in supporting bluebird populations.

The bluebird nest box is easily and inexpensively constructed by even novice woodworkers; click here for instructions.

Many cavity nesters—including chickadees, swallows, wrens, titmice, owls, ducks, purple martins and nuthatches—will happily occupy a bluebird house.

Putting Up your Nest Box
Placement of your nest box will help determine which species of birds will be attracted to it. While bluebirds crave wide-open spaces, chickadees like forest edges. Consult the Birdhouse Network or a good birding book for habitat guidance.

Some birds like boxes mounted in trees or on the sides of buildings. Unfortunately, such sites are accessible to predators such as cats, raccoons, squirrels and snakes. When erecting a nest box in an open setting, you have the chance to build some protection.

The pole may also be made slippery with a coating of Vaseline or other grease. The grease has the added benefit of trapping ants, which can sometimes be nest-box pests.

A predator baffle should be mounted on the pole beneath the nest box. The most common baffle is a cone made of sheet metal; another is constructed of a larger metal tube mounted over the pole. Baffle-building instructions are widely available at birding sites on the Internet or in birding books (try Bill Thompson III’s Bird Watching for Dummies). Baffles may also be purchased.

The entry hole to the nest box can be protected from chewing pests (like squirrels) with a square of thin sheet metal. Cut a hole into the square (slightly larger than the opening to avoid harming the birds) and tack it over the entrance, being careful that no sharp ends poke into the interior of the box.

Monitoring for Unwanted Guests
Nest boxes are built to open for easy monitoring. You need to know right away if a pest bird, such as a house sparrow or starling, has taken up residence in the nest box, or if predators or other pests are getting in. Don’t worry—gently opening the house for a moment or two twice a week won’t scare away a nesting pair.

House sparrows and starlings, both non-native species, are aggressive, tenacious and will quickly take over nest boxes—if you let them. Starlings, which are larger than many of the cavity nesters, can be prevented from entering the box by using an opening of 11/2-inches or less. This means they can’t access a basic bluebird house.
Sparrows are trickier, because they’re small enough to get into most nest boxes. If a sparrow sets up housekeeping, simply dump the nest out. Sparrows can be stubborn, often returning again and again to rebuild. If worse comes to worse, take the house down for a while, until the sparrow moves on. Many desirable birds will raise more than one clutch of chicks in a summer, moving houses in between. You could get your bluebird yet!

In the course of monitoring, you may find tiny bird lice crawling about the nest box or see grayish blowfly maggots attached to the chicks, but don’t worry. All birds host some parasites; generally they won’t badly harm the chicks. And although these creepy-crawlies might make you squeamish, bird parasites are not interested in human beings.

You may also find that paper or mud wasps have moved into your nest box. Wasps are territorial and will sting you and the birds, so use a long stick to scrape out their nests. Never use pesticides, which could kill not only the wasps but also the birds.

Once the chicks are ten days old, don’t open the box. This prevents panicked fledglings from jumping to the ground. If this does happen, don’t worry. Simply pick up the chicks and return them to the nest. It’s a myth that bird parents will reject any nestling that’s been touched by a human.

It’s generally recommended that you clean out the nest box in the fall. Be sure to wear gloves and avoid breathing the dust in the box. Some birders also take the house down and pour boiling water into it to eradicate parasites.

After cleaning, remount the house. Migrating and over-wintering birds will appreciate a place to roost on cold, snowy nights.

Happy Birding!

Hillary Nelson is a writer who lives in Canterbury, New Hampshire. Her Child’s Play column and op-ed pieces appear in the Sunday Concord Monitor.

David A. Petty provides clients with creative advertising illustration through digital photography and video. His business, DPImaging, is located in Hampstead, New Hampshire, and his portfolios can be seen at dpidp2.com.