The incubation period for bluebird eggs is 12 to 14 days. Nestlings remain in the nest 18 to 21 days before they fledge. Remove bluebird nests and those of other birds as soon as the young birds have fledged. Don't be discouraged if your nesting boxes are not used the first year. If bluebirds are not common in your area, it may take them a few seasons to find your new box.
Bluebirds generally return to the same area each year.