The wife & I had three squirrel populations. We told them apart by their tails. Long tails with a dark stripe, short tails, and white margined tails. In order to keep them off the birdfeeders, we started putting out corn and suet in a bushytail-designated feeding area.
The white tails were quite greedy and annoyingly aggressive about raiding the birdfeeders even before they'd go for their own food. They're all dead now. Had to shoot a couple of gluttonous short tails, too. Long tails were most cooperative and therefore prospered, eventually driving the short tails out of the squirrel area by weight of numbers. So, they currently just fight over the squirrel food among themselves.
We had a "misfit" as well. He'd sustained some type of neurologic injury, probably from a previous car strike, as he had a big area denuded of fur on his back. He could run, albeit slowly. I probably could have caught him if I had sprinted after him. Could climb, but would never jump from tree to tree. Also, whenever he sat up on his haunches to nibble on the corn cob, he would oscillate back and forth like a tall fir tree in the wind. Named him "Wobbly" because of that. Occasionally, he'd just up and fall off the feeder but would always manage to catch himself with a front paw, whereupon he'd just climb back up and nonchalantly continue munching. Haven't seen him for a while since cold weather set in; so, he's probably no longer with us. We kind of miss the ol' guy.