Log Bird Feeder - 23 DIY Birdfeeders That Will Fill Your Garden With Birds (my note: I haven't looked at all of these, but at least one is a terrible idea. The window birdfeeder -- birds could fly into the glass and hurt themselves.
Driftwood on the outside and cut the tops of logs for the top piece. Add a piece of glass on top. Would this work around a base of two tires with a cheap round wood table top and bottom? Add wheels on the bottom?