Posted by Mary Bergerson on January 19, 2006

Q: How can you explain the way birds space themselves on a power line?

A: It's obvious that you're a good observer! There is a very good reason why birds space themselves this way. Many animals, and this includes humans, have what is called an "individual distance" - an intolerance for members of their own species to be within a certain distance or "comfort zone". These distances vary from species to species but for many birds, the comfort zone is merely the distance beyond which one bird can reach over and peck its neighbor.

In the fall large flocks of Starlings congregate and are often seen sitting on telephone wires spaced out just as you've noticed. Each bird wants to be close to its neighbor but not any closer than its "individual distance" makes it comfortable - hence the spacing. If you've ever been to a social gathering and found yourself uncomfortable with someone who's individual distance is "closer" than yours, you may have have experienced this phenomenon yourself! In fact, since some cultures have a much closer individual distance tolerance than others, when some cultures mix, it can make for some uncomfortable gatherings. Thanks for your great question.

John Wiessinger ( January 20, 2006)