I made a similar birdhouse this spring and have ended up getting quite a few people wanting me to make one for them. One is even a paying customer. So this one is for her. It's from an old dried up and split walnut log. It has a big crack, 3/8" wide going up the back side. These are a little like turning a toothpic out of a tree trunk. You end up with a lot of shavings. But it's a pretty good way to use some logs that you've let sit around for too long. This one is 20" tall and 11" diameter. There's also a picture of how it started out (the top half). Finish is a couple doses of Thompson waterseal with a couple coats of Spar Urethane over that.