Here's a poplar we did yesterday. Large rotten branch with a squirrel hole on the opposite side. Squirrel got out alive. He was part of a "relocation project".
http://www.youtube.com/watch?v=jkP_WPYvD...mp;feature=plcp
http://www.youtube.com/watch?v=jkP_WPYvD...mp;feature=plcp