The female will construct the nest in four to five days with only minimal help from her mate. She also does the incubating, as the male does not have a brood patch. However, a male will sometimes spend nights in the nest along with his mate. The female will lay four to five light blue eggs that will take 13 to 15 days to hatch. The male brings food to his mate and the young during the critical first few days of feeding.
Bluebirds act like tiny hawks, in their perched hunting position, waiting patiently for a crawling insect or beetle to show itself. They then pounce on it and bring the food back to the nest. The young will fledge in 15 to 20 days. Even though the parents will keep feeding them, the fledglings can find their own food in about two weeks.
Here in New England the bluebirds have two broods, — and occasionally three, — as they do in the south if we have spring and summer weather that cooperates. Some of the youngsters from the first brood are often seen bringing food to their new siblings. They teach us much about the bond of family. This often continues into the fall and at times they stay together until the following spring.
The key to attracting bluebirds to nest in your yard is having potential nesting boxes, food and water. Bluebirds do prefer more open areas, so if your yard is heavily wooded you’ll enjoy many other nesting birds, but probably not bluebirds.
Nest boxes should be placed at the edge of an open area, facing a southerly direction to avoid cold winds and rains early in spring. Since bluebirds are territorial, boxes should be placed about 300 feet apart.
To be successful, aggressive house sparrows must be kept at bay by removing their nest material and even trapping and removing the sparrows. They are so mean that they will kill the adult bluebird right in the box. Tree swallows also compete for bluebird houses, but they are good competition. Swallows, like purple martins, eat many flying insects and they are desirable birds to have around. If they are present, you might consider pairing houses, allowing bluebirds in one and the tree swallows in the other.