Red Squirrels (Tamiasciurus hudsonicus) are much smaller than the other squirrels I see around Kalamazoo. (Flying squirrels are even smaller but since they are nocturnal I hardly ever see them.) Red Squirrels also quicker than the Fox Squirrels and, for some reason, more charismatic.
Now they are busy filling their caches with food. While they aren't true hibernators, I don't remember seeing them during the winter. Perhaps they're spending the cold months in their nests enjoying their stored harvest.
I teach economics at Kalamazoo College. My wife is also an economist. We were on sabbatical in Europe for the 2014-15 academic year. (Salamanca, Spain, followed by Oxford, UK.) We were in Uruguay for the 2006-7 academic year.