This male Pine Grosbeak fledgling likes the convenience of fresh water near an "escape tree". Our neighbor used his chain saw to cut a deep, circular groove about one inch in from the outer edge. Then he did criss-cross cuts to the same depth. We followed behind him with a hammer and chisel and cut out each small cube of wood. Then our neighbor repeated his cutting and we our chiseling two more times to get an inside depth of about 6 inches. I then drilled half-inch holes in the bottom and sides to the outside for drainage. Then I filled the bottom of the cavity with about a 2-inch layer of alfalfa pellets and topped that with about 2 inches of pea-size gravel into which the bird bath (which is a 14-inch diameter plastic saucer) is nested. When it rains or I refill the bird bath, water filters down through the gravel and activates the alfalfa pellets which is my all-purpose organic fertilizer. The dissolved liquid portion flows out through the drainage holes and feeds the plants surrounding this old stump.