Large Rats at Work

While inspecting my garden this past Saturday, I noticed this (pictured) damage to a small deciduous tree that is placed in the middle of my Evergreen bed.  I think it occurred sometime during the previous week, although, since I didn't see my garden in daylight hours last week, I am not absolutely sure of the exact day.   ProfessorRoush is definitely NOT an expert on wildlife biology and behavior, nor do I have any extensive knowledge of garden pests or their control beyond personal experience, but I'm pretty sure that the picture at the left is evidence that several large prairie rats with long skinny legs, fluffy white tails, and antlers have been visiting my garden.  This particular varmint must have been suffering a mighty itch along those antlers to scratch out this big of a section of trunk.  Alternatively, I suppose this rutting stag could be some sort of a garden snob offended by the fact that I put a deciduous tree in a bed otherwise composed of evergreens, and he simply expressed his displeasure by trying to off the tree.

The particular tree in question is a volunteer Double-flowering Red Peach (Prunus persica 'Rubroplena'), an offspring of one of my other landscaping trees, that cost me nothing as a volunteer, but with whom I was well-pleased.  The trunk is currently about three inches in diameter and the tree about 8 feet high.  I don't have a vast experience with damage of this magnitude, but I'm pretty sure it will permanently damage the tree.  Any bets out there?

I'm not sure why this tree is the only one damaged at present, but truthfully, fully half my young trees are protected by fencing wire just for this reason.  And I'm partially at fault here, both for not circling this tree with fencing and because I haven't yet instituted my standard deer repellant program this winter. I guess if I had to pick a tree to sacrifice for the purpose of honing the antlers of rutting deer, this was about as good as I could have chosen, but that doesn't mean I'm mitigating the death sentence of the bounding hart.  In the long run, I may have to fell my baby tree, and if I catch the perpetrator in my garden, he's going to unwillingly contribute more organic fertilizer to my garden than the little pellets he left near the tree. We must protect the children (or in this case the baby trees).