Be sure young birds will be able to leave the nest. Roughen the inside of the nest box below the entrance hole or attach a sheet of 1ǚ_inch galvanized wire mesh, so fledging young can climb out easily. Provide woodpeckers, waterfowl, and owls with nest material. Many cavity_nesting birds will add their own nest material, but the woodpeckers, waterfowl and owls prefer nest boxes with 2ι inches of dry sawdust or woodchips in the bottom.
Nesting Ledges. American Robins, Say's Phoebes, and Barn and Cliff Swallows will not use nest boxes, but they will next on platforms that are open on three sides. Platform nest ledges should be 6ν inches wide, 6ν inches long, and at least 8 inches high. Nest ledges can be easily fastened under the eaves of houses, buildings, bridges or on trees. They may be placed near a window where the behavior of birds using them can be easily observed. Place the nest ledge 8–16 feet above the ground.