My son-in-law built this multi-variety bird feeding station. Here are some photos and some sketches. Materials can vary from fence=tubing to schedule 40 pipe. This is a labor-intensive project requiring drilling steel tubing or steel pipe, digging, mixing concrete, bolting pieces together, and so forth. The individual feeders are purchased for various species of birds, including hummingbirds, redbirds, finches, and various songbirds.
