Fox Squirrel (Sciurus niger)
Location: Boulder, Colorado, USA
This is a Fox Squirrel (Sciurus niger), one of three kinds of tree squirrels native to Colorado. The species was unfamiliar to me, so of course I looked it up. According to the Web site of the Colorado Department of Natural Resources: "Fox squirrels eat fruit, nuts and buds, and bury nuts for winter (and because they are forgetful, they plant a lot of trees)."
That last bit made me smile. I had never thought of squirrels as inadvertent tree planters, but I suppose that does happen.
I saw this little guy foraging in a garden in Boulder, Colorado. He appeared to be digging up nuts and seeds rather than burying them. Note the bits of dirt on his chin!