The ornamental design for the bird house, as shown and described.
FIG. 1 is a perspective view of a bird house showing my new design;
FIG. 2 is a front view of a bird house;
FIG. 3 is a back view of a bird house;
FIG. 4 is a left side view of a bird house;
FIG. 5 is a right side view of a bird house;
FIG. 6 is a top view of a bird house; and,
FIG. 7 is a bottom view of a bird house.
The broken line showing of the hanger, perch, opening, and bottom closure are for the purpose of illustrating the environment and boundary related to the claimed design and forms no part of the claimed design.