Squirrel Apple Thief

Not a single apple remains on the four apple trees (or on the ground) in my back yard (well really 2 crab apple trees and 2 other apple trees (see Two Apple Sticks - yellow transparent semi-dwarf and golden delicious dwarf).  So who are the culprits - deer, dog or ...... squirrel?    The picture below incriminates the squirrel along with some videos that I have of the branches shaking with no wind present. But you have to look carefully - he is feasting on an apple underneath the golden delicious dwarf tree!