|Photo by J.J. Meyer|
In case you missed my column in today's Orange County Register, here it is:
I’m suffering from the common birders’ affliction I like to call “empty nest-box syndrome.” It’s a disheartening malady; it occurs when you put up a perfectly good nest box and birds don’t move in.
Last year, I heard no sweet tweets, no pitter-patter of tiny bird feet. Nothing. I even considered putting up a “free rent” sign to entice them.
Well, it’s time to try again because many cavity-nesting birds—those that builds nests inside enclosed areas such as a hole in tree—are already house shopping for spring.
Western bluebirds, along with Bewick’s wrens and house wrens, are among the most common cavity-nesting songbirds in Orange County. Other cavity nesting species include: tree swallows, purple martins, wood ducks, chickadees, titmice, nuthatches, woodpeckers, flickers, American kestrels, barn owls and screech owls.
House sparrows also use nesting boxes and often take over one occupied by other birds by killing the babies inside. Scientists suggest discouraging these non-natives from setting up house.
Installing a nest box can be beneficial. Bluebirds were on the decline until the Southern California Bluebird Club, a local conservation group, began hanging boxes in parks, cemeteries and other open spaces across the county. With limited natural cavities, such as woodpecker holes, bluebirds adapted quickly to the man-made boxes.
Although a nest box can be considered a birdhouse, not all birdhouses are functional nest boxes. Cute and whimsical appeals only to humans, most colorful birdhouses are little more than garden ornaments.
According to the Cornell Lab of Ornithology, a nest box needs specific features to be functional and safe for the birds. The box needs to be the right size for the species you’re trying to attract. For example, wrens are happy with an 8-inch tall house and a 4-by-6-inch base. Wrens also need a 1¼-inch hole, which is large enough for them to come and go, but small enough to keep larger uninvited guests out. Perches are unnecessary and may attract larger predatory birds. The box should be made of untreated, unpainted wood with adequate ventilation and drainage holes. Grooved interior walls are necessary for the birds to climb out. A box should always have door that opens for clean out at the end of the season. It also needs an extended, sloped roof to prevent raccoons and other predators from standing on top and reaching in. And the roof should be constructed of wood instead of metal, which can cause the birds to overheat inside.
Like any good real estate investment, consider location.
Although the construction of my own wren box was correct, the location was wrong. Mistake #1: I secured it to a tree instead of a pole. Predators could have easily gotten to the eggs or babies inside. Metal predator guards can be placed on a pole for additional protection. Mistake #2: It was located on the side of our house where the wind whips through. The opening in the box should always be placed out of the prevailing wind. Mistake #3: It was too low. A wren box should be five to 10 feet off the ground. Cats and squirrels can easily jump onto a box if it’s too low. Mistake #4: The box was too close to three active birdfeeders. The noise and activity may have kept nesters away.
I’m planning to fix these mistakes with a new location this year.
If you are also suffering from empty nest-box syndrome, find the cure at nestwatch.org.