This post isn’t quite about ecology. But it’s about a phenomenon that many ecologists have ample experience with. A study out last week in Current Biology found that when people get lost in the wilderness, they actually do walk in circles.
Jan Souman of the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, and his colleagues set volunteer hikers loose — without maps, compasses or GPS units — into a forest in Germany and a desert in Tunisia. They found that in the presence of a clear sun or moon, the hikers were able to walk in a relatively straight line. But on cloudy days, the hikers had more trouble. Little deviations from this straight line compounded on themselves, and the hikers ended up walking in not just one circle, but at times many loops back on themselves.
In an article in The New York Times, Souman said that although the brain takes in many signals when navigating, such as visual cues and acceleration and speed cues from the inner ear, these cues are only relative to an individual’s current position. Without a landmark, like the sun or moon or a distant tower, little mistakes build up, causing people to walk in loops.
The study is also evidence against the idea that if people walk in circles, it must be the built-up consequence of walking long distances when one leg is slightly longer than the other: Souman found that deviations occurred in both directions for individuals.
So now, the next time you’re hiking or gathering data in the field and you get lost, comfort yourself. Walking in circles is normal behavior. And maybe, in these instances, a philosophical approach is best. As Winnie the Pooh expressed to Rabbit when they were lost in the Hundred Acre Wood and kept running across a muddy pit:
Winnie the Pooh: Say, Rabbit. How would it be if once we’re out of sight of this old pit, we just try to find it again?
Rabbit: What’s the good of that?
Winnie the Pooh: Well, it’s just that we keep looking for home, but we keep finding this pit. So I just thought that if we looked for this pit, we might find home.
Winnie the Pooh and Tigger Too, 1974
Souman JL, Frissen I, Sreenivasa MN, & Ernst MO (2009). Walking Straight into Circles. Current biology : CB PMID: 19699093