Not sure what, but this is the first year for that tree (got it from Lowes and it's doing great other than this). On one side of the tree in particular, it looks like the leaves are being chewed on but we have never seen any insects on the leaves or elsewhere on the tree for that matter.
Not sure how old the tree is, but it's about 7ft tall and full of leaves aside from the ones being bitten up.
Any thoughts on what to look for? Nothing seems to be bothering our peach or cherry trees that are nearby, and nothing is touching the pear tree on the other side of our yard either.