Thanks for the replies, I'm not getting the WT for beaver, I'm getting it for wolves. It just sounded like fun to get the beaver sound and watch their reaction. There is a beaver near my house in a closed area that is huge. I've trapped lots of 60lb beaver and they would look like kits next to this one. I saw him on the bank just once and he looked like a bear.
Rich, if you want to record a bark, try a dogwood tree, the maple is too sweet to bark much.