Q: I work in Harrisburg and catch the bus at the CAT Transfer Center at Market Square at 4:45 p.m. I admire the groups of pigeons that swirl around the tops of the tall buildings there, contracting and expanding and seeming to follow different individuals as the cloud of birds changes direction. It looks positively joyous. Are they just having fun? Lynn Ahwesh, of Camp Hill.
A: While it does look like a lot of fun, from our human perspective, no evidence exists to indicate that a pigeon can experience joy. More likely, what you're observing is typical flock behavior, with one or two birds starting a movement and the rest of the flock following that lead. Flock behavior is a handy defense mechanism for spotting and eluding predators.
Frank H. Heppner, a zoologist at the University of Rhode Island, studied flock behavior in starlings by setting up a pair of movie cameras to film the birds at three frames per second. When he examined the film one frame at a time he saw that it wasn't one or two birds always taking the lead. In a dynamic equilibrium, various members of the flock found themselves in the lead at different times.