I was eating lunch outside on an early autumn day last week. The breeze was gentle, but the air tingled with a hint of cooler days to come. From the side of my patio, I felt a flicker of movement and sensed something coming toward me. In the split second I turned my head to look, the sensation was gone and the tree beside me stood still.

Just the breeze, I thought, as I went back to work on my salad. Then I saw another flash of motion in that same tree. I decided it must be one of the hummingbirds that have been zipping around my house all summer.

I made a big dent in the salad before I saw the movement again. This time I had the sense of something floating from a high branch to a lower one, far too slow to be a hummingbird. A leaf on the gentle breeze? A falling limb? My curiosity got the best of me.