Bluebirds are members of the thrush family (Turdidae), the same family to which the American Robin and other thrushes belong. All the bluebird species are distinguished by their blue coloration. Eastern bluebirds (Sialia sialis) are the species most likely to be found here, and have red breasts and chins. Bluebirds require a cavity, or hole, within which to nest. Since they are unable to excavate these cavities themselves, they are referred to as secondary cavity nesters. Woodpeckers are primary cavity nesters, and in natural habitats bluebirds will search out old woodpecker cavities to construct their nests. Woodpecker cavities can be replicated by a bird house or nest box. Bluebirds do not distinguish between the 'real thing' and the 'fake'. They will readily adapt a nest box as their home. This acceptance of artificial housing has led to the development of bluebird trails by thousands of people all across North America. Bluebirds prefer to nest in open fields, prairies, and meadows that contain scattered trees and shrubs. So the location of this geocache would not really be ideal for bluebirds, particularly since the opening faces prevailing winds. But this cache location is ideal for birdwatching, and easy to access from trails.