There's something about bluebirds that makes otherwise normal people turn goofy and excitedly phone their bird-watching friends at the first sighting in spring, or when a pair sets up housekeeping in the backyard nesting box, or when a bright blue streak against the snow turns out to be a wintering bluebird. Even in cold climates about a third of the bluebirds don't migrate to warmer climes in winter, and you may spy them feasting on the fruits of winterberries, Virginia creeper, sumac, hackberry, and hawthorn. Providing fruiting shrubs is important, but 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, and with their habitat disappearing around the world, they need all the help we can give.
Tempting Food
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. Suet is easy to make, and this recipe from the Massachusetts Bluebird Association is reported to be much to the birds liking:
A Tempting Feeder
Offering the food in a feeder that resembles a nesting box is another way to attract wintering bluebirds. 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.
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 they can't see inside.
A study at the University of Illinois demonstrated just how protective a nesting box can be in winter. A zoology professor 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 79°F!
So help your local bluebirds make it through wintery weather. It's the least we can do considering they are sharing their native habitat with us.
Illustration by M.E. DeJohn