Update! A pair of chickadees seem to be calling this home now. Here's one standing guard while the other gets nesting materials: http://home.comcast.net/~tweezak/birds/img-3.jpg Here are both wondering what I'm up to: http://home.comcast.net/~tweezak/birds/img-1.jpg * * * *
This is based on a design by Dan Aragon on eHow. I made a few changes and sketched it up. Key points: there is no perch. Big birds like jays will sit there and eat all the babies. I put gaps under the eaves for ventilation as my birdhouses will end up in the sun part of the time. I drilled the hole 1.25" diameter and put it toward the top so the babies are less likely to fall out. The model doesn't show it but I use zinc plated hinges and a latch (like from a screen door) to attach the bottom. That makes it easy to clean out the house after a year or so. I glued and nailed mine together and then rubbed it down with mineral oil. For hanging I got some brass chain and a couple of screw-eyes. All in all you can build this bird house for less than $5.