Kat and I were walking onto campus this afternoon and I saw a brownish-colored squirrel, rummaging around in a nest-like bunch of twigs about 20 feet from the ground, in a birch tree. I thought at first that he might be preying on the eggs of some bird; however, I quickly realized he (or she?) was building a nest!
I wish I could tell you I have some great photos or even video, but I had nothing with me to capture this magical moment! My description will have to suffice. Sorry!
The squirrel would hop from thick trunk to trunk, looking for twigs. He then nibbled the twigs off, usually to a length of 10-15 inches (from what I could judge from the ground). Then he would secure the twig in his mouth, hop back over to the nest in the crook of a large branch, and weave the twig into place. I watched for about ten minutes as he did this, twig after twig. I tried to remain hidden, but it's possible that he saw me and was spooked; he hopped his way over to an adjoining oak, then disappeared.
I never knew that squirrels even built nests, much less nests in trees. But now I've seen one in construction. I just wish I'd had my camera. He was really cute.