A question about your squirrels

My friend Asha just gave a copy of Squirrel Wars: Backyard Wildlife Battles & How to Win Them to her mom for Father's day. Which reminds me of this method of controlling squirrels in your back yard.

Which, in turn, reminds me that I've been meaning to ask around about color morphs. Where I grew up, gray squirrels were gray. I lived in Boston for many years, and gray squirrels there were ... also gray. Well, the ones in Harvard Yard were more a shade of grey. Anyway, here in the Twin Cities area, they are pure white, almost jet black, or gray. Some of the gray ones are reddish gray.

So, here is my question: Am I living in a region where there is unusual diversity in the color morphs of Sciurus carolinensis? What is the diversity of gray squirrel pelt color in your region?

And why?