One of the several membership publications put out by the Cornell Lab of Ornithology is Birdscope. For those not aware, Birdscope is a seasonal newsletter that publishes the latest bird-related news, insights to bird-related questions, citizen science projects, tips about bird watching, and other similar educational resources. I've been receiving Birdscope for about a year now and just recently realized that anyone can access a majority of the publication online - both current and past issues.
Now that you are aware of this great resource, I wanted to share one of the articles that caught my interest recently. It first broke in the summer 2008 edition, titled Looking for the Perfect Fixer-Upper. In this article Cornell scientist experimented on which type of nest house chickadees prefer. A series of different types of houses were set out and what they found was very interesting. First, chickadees prefer birdhouses filled with wood shavings, giving them something to excavate. Second, the type of house preferred in most cases was an artificial tree snag, made from 4" PVC pipe. How cool is that?
The plans referenced in this issued weren't very detailed but the latest issue of Birdscope (winter 2009) contained better detailed plans for making your own nest tube (see links below).
If your a do-it-yourself type and would be interested in trying to attract a pair of nesting chickadees to your yard, these artificial tree snags may be the ticket! Here are a couple detailed plans that were referenced in Birdscope:
...don't forget to add the wood shavings in the tube after construction.
When complete, you can paint it to look like a tree or give it a camo paint job so it will blend in with the surrounding landscape.
I'm looking forward to trying this myself. I'll keep you informed on how it goes.