Bluebird Facts Eastern Bluebirds live in open country around trees, but with little understory and sparse ground cover. They’re most common along pastures, agricultural fields, suburban parks, backyards, and golf courses. Food sources include insects caught on the ground are a bluebird’s main food for much of the year. Major prey include caterpillars, beetles crickets, grasshoppers, and spiders. In fall and winter, bluebirds eat large amounts of fruit including mistletoe, sumac, blueberries, black cherry, tupelo, currants, wild holly, dogwood berries, hackberries, honeysuckle, bay, pokeweed, and juniper berries. Nesting Facts: Eastern Bluebirds put their nests in natural cavities or in nest boxes or other artificial refuges. After a male Eastern Bluebird has attracted a female to his nest site (by carrying material in and out of the hole, perching, and fluttering his wings), the female does all the nest building. She makes the nest by loosely weaving together grasses and pine needles, then lining it with fine grasses.     Clutch Size: 2–7 eggs     Number of Broods: 1-3 broods     Egg Length: 0.7–0.9 in     Incubation Period: 11–19 days     Nestling Period: 17–21 days     Egg Description: Pale blue or, rarely, white.