In the Garden:
Summer nesting boxes also can provide winter protection for bluebirds that brave the cold instead of migrating.
Bluebird of Happiness
There's something about bluebirds that makes otherwise normal people turn goofy, and I count myself as one afflicted. Fortunately, I have some friends and neighbors who can relate. We call each other to share news of the first sighting in spring, when a male and female finally settle into a backyard nesting box, or when the young first appear.
Two years ago I saw some bluebirds for the first time during the winter, feasting on the fruits of my winterberry shrubs. After some excited phone calls, I learned of similar sightings in the area -- more than usual, according to a local bird-feeding store. Even in cold climates about a third of them don't migrate to warmer climes, but since they don't typically visit feeders, you might not see them. They depend on the fruits of native trees and shrubs like red cedar, Virginia creeper, sumac, hackberry, hawthorn, and winterberry when their preferred diet of insects disappears in winter. But there's competition for the berries, and oftentimes they're hidden under snow and ice. By late winter, natural food sources may be depleted. Bluebird lovers take heart: there's something we can do to help. These birds will visit feeders with the right enticement.
Bluebirds' beaks are not designed for cracking open the seeds in most birdseed mixtures. But if you serve up shelled sunflower seeds, cheese, nuts, small raisins, or suet, the birds may come to dine. When I searched on the Web, I found lots of success stories about attracting bluebirds to feeders in winter, and several suet recipes that the birds seem to find tantalizing. Most were variations on this one from Massachusetts Bluebird Association:
1. Melt 1 cup lard or suet with 1 cup peanut butter (plain or crunchy)
2. Add, one at a time, 1 cup cornmeal, 3 cups oats, and 1 cup sugar.
3. Chill mixture in a pan, then cut into pieces that fit your feeder. Freeze extra for later.
In a Tempting Feeder
Offering the food in a feeder that resembles a nesting box is another way to attract your wintering bluebirds. Perhaps because they nest in cavities, bluebirds seem to prefer a feeder that feels like one, and a nesting box is essentially a manmade cavity. One recommended design is an enclosed hopper type, with a hole at each end for the birds to enter. Some people have actually trained bluebirds to come to these feeders when they whistle or call. I'm giddy at the prospect.
A Wintry Home
Bluebirds also need shelter from the wind and cold. Generic roosting boxes are available, but bluebirds don't use the perches common to most designs because they sleep in a huddle on the floor. Summer nesting boxes suit them better, so leave the boxes up year-round, and cover any large ventilation holes with foam weatherstripping or some such material that can be easily removed in spring. Since the birds like to peek into the house before entering, don't seal it up so tightly that the birds can't see inside.
I was impressed by the results of a study that demonstrated just how protective a nesting box can be in winter. A zoology professor at the University of Illinois recorded the temperatures inside and outside a box under the eaves of a building, where a house sparrow was taking shelter at night. When the bird was out of the box, the inside and outside temperatures were the same. When the bird was in the box, its body heat and exhaled breath raised the temperature dramatically. On one 18-degree night, the temperature inside was a toasty 29 degrees F. This could mean the difference between surviving and perishing in a New England winter.
So, the boxes and feeders are hung up with care, in hopes that some bluebirds soon will be there!
Care to share your gardening thoughts, insights, triumphs, or disappointments with your fellow gardening enthusiasts? Join the lively discussions on our FaceBook page and receive free daily tips!