Open Season

Acorn 1: In Wake in the wild, when you come to the fork, go left. It's at the dead end.
Acorn 2: Backtrack after Acorn 1, sticking to the left wall.
Acorn 3: When you earn the smell skill, go down the path that isn't blocked by skunks. Turn right, then hang a left.
Acorn 4: Get over the second fence in the level hoof-it.
Acorn 5: At the river in hoof-it, jump over the log on the left.
Acorn 6: In Scare Bear, throw elliot at this after moving towards the cabin
Acorn 7: In mine shafted, jump at the lanterns to get acorn 7.
Acorn 8: In mine shafted, at the second sequence of three lanterns, it's obtained by finished that set.
Acorn 9: In Hunted, watch the first shot of open season.
Acorn 10: In Hunted, go to the squirrels' tree. Throw Elliot to the ledge on the left.

*Credit goes to Manatee from x360a.com