I once watched a very special squirrel for an entire spring. This particular squirrel had come into some sort of accident that mangled it's tail, leaving it with just a little puff sprouting from it's rear end, rather like a bunny rabbit. I had two theories:

1) it would not be able to climb trees as well, but rather would be slow and awkward due to being off-balance.

2) no squirrel would mate with it due to it's deformity

While I cannot vouch for it performing more acrobatic squirrel moves up in the trees, nor did I actually SEE it do the wild thing, I did observe my young friend running up and down trees after other playful squirrels all spring.

The Happy End