If you have never seen one, do yourself a favor and do a Google image search for the Kaibab squirrel. They have white tails and these awesome little ear tufts, and they only live on the Kaibab Plateau north of the Grand Canyon.
It’s an awesome example of evolution by geographic isolation; their white tails give them camouflage cover in the winters when there’s snow. Here’s the good ol’ Wikipedia link.
I mention the little critters because one of them figures prominently in a short story I’m writing called “Kaibab Unbound.” It’s intended to be a teaser for HOUNDED, featuring Atticus and Oberon getting into a spot of trouble on the Kaibab Plateau.