One morning some years ago, I heard the dogs carrying on out by the big maple..  Went to see what they had treed..  There was a young woodchuck - about 8-9 lbs - laying as flat as it could, on a limb about 10' off the ground.  Cahined the dogs, put water & food at the bottom of the tree.. He wouldn't leave until I took the dogs to the barn & chained them there.. 2 days later.  I'll bet s/he was one hungry chuck!  I grew up in the country - never heard of a woodchuck climbing a tree.  Wouldn'ta been sporting to kill it, but they are good eating.