While the plump-breasted worm-eating robin is entitled “The harbinger of spring,” there is no doubt that sightings of the early bluebirds are eagerly awaited as well. As they begin to leave their winter hangouts and appear more often outside the kitchen window or perched near the garden, we wonder what we can do to keep them around so that we can enjoy seeing them.
The Eastern Bluebird, which inhabits our area, is a member of the Thrushes Family Turdidae, which includes the Woods Thrush and the American Robin, and has a scientific name of Sialia sialis. Blue on its head, back, tail and wings, it has a rust red colored breast and likes open country with scattered trees, orchards and farmland, while it dines on insects, worms and berries.
It may surprise some, but bluebirds actually do not migrate south for the winter months, but instead move deeper into nearby forests to spend the colder months. They reappear in early spring, once the temperatures have warmed up.
They are always welcomed by gardeners, as their diet is largely made up of insects caught on the ground, such as caterpillars, beetles, crickets, grasshoppers and spiders. In the winter months, while they hide out in the deeper woods, they feed on large amounts of fruit, such as blueberries, black cherry, dogwood berries and honeysuckle. They can be seen often perching on wires or fence posts overlooking open fields. They will flutter to the ground to grab an insect, or sometimes will catch their prey in midair. The boxes and tree cavities where bluebirds nest are in great demand by the birds that require holes for nesting, and the male bluebirds will attack other species if they are considered a threat. The male bluebird attracts a female by carrying nesting material into and out of the nest, and once the female enters the nest, the pair establishes a bond, which often remains for several seasons.
Thereafter, the female does all of the nest building and may use the same nest to hatch and rear multiple broods. She will lay between 2-7 eggs and may produce up to 3 broods throughout the season. The incubation period for the eggs is 11-19 days and the nesting period runs from 17-21 days.
Research has shown that their populations have steadily increased since the mid-60s. While aggressive introduced species such as the European Starlings and House Sparrows have competed for existing nest holes, the development of bluebird trails and other nest box campaigns designed to keep out the sparrows and starlings have aided in bluebird recovery.
While bluebirds do not often come to typical bird feeders, they will respond well to the presentation of mealworms. Simply placing several mealworms on a plate that sits on a picnic table will attract them and they will become regular visitors if you keep the plate well supplied.
On the other hand, adding bluebird nesting boxes to your yard may be your best opportunity to increase the presence of bluebirds. You can find plans for building these boxes on the internet and even view their building on YouTube. If you prefer, bluebird box kits are available from the Pennsylvania Game Commission’s office in Jersey Shore. They are reasonably priced (if you buy more than one, they are $10.00 each) and include all of the necessary wood pieces, screws and nails for complete assembly.
These boxes should be mounted between 3 to 6 feet above the ground. Research has shown that bluebirds prefer the boxes that face east, followed by a box facing north, south or west. Tree swallows are the greatest competitors for these boxes. To increase the possibility of their use by bluebirds, they should be put up in pairs. The pair should be placed 15-20 feet apart and the pairs of houses should be located 300 feet from each other. Boxes should be cleaned out prior to their first use in the spring and subsequently should be cleaned out of all nesting material immediately after a brood leaves to encourage the reuse for another brood.
Once you have established several bluebird nesting boxes, there is little effort needed to maintain them, and they will provide you a great opportunity to enjoy this beautiful bird as it nests and feeds in your own backyard.