The other day I was walking along the grassy edge of a barley field with my camera. As I walked, I reflected, with wonder, on how insects, with brains smaller than a pin head, could not only fly, but navigate and maneuver with such marvelous precision. I had observed dragonflies exhibit this ability on many occasions when I was photographing them. They would take-off after a minute or so of rest on a plant stem, fly around, covering perhaps 15 to 30 feet in 5 or 10 seconds, then land exactly where they’d been moments before, on the same spot, on the same plant stem. (It seemed as though the short flight might have been to keep a look-out for predators that might have been creeping up on them while at rest. Or, perhaps it was preemptive, to dash the hopes of any such predator.) I’d learned, when photographing dragonflies, not to look up from my camera’s viewfinder when the subject took off from its perch, because, more often than not, in less time than it took to catch sight of them in flight, they’d be back within a fraction of an inch of where they’d been before the flight. It seems incredible! Just the act of landing on a moving stem in a wind seems incredible. What knowledge of their location do they retain in their brains, and what method do they employ to recognize the same point, again? Since they can do this in a brisk wind, it would seem they must use sight, and must retain some image of their surroundings in their tiny brains.
At this particular moment I was following a dragonfly, a male “Widow Skimmer”, waiting for him to land so I could, with luck, get a close-up shot. As I trailed along, my attention was attracted by a “Cabbage White” butterfly fluttering by overhead, perhaps eight feet off the ground. Its flight path was irregular - darting this way and that, up and down, perhaps twelve inches in a given direction at a time, ever moving, but irregularly setting off in a new direction. Its motion was so jerky it was hard to follow with the eye. When the wings are edge on, the butterfly is difficult to see, and the eye tends to continue along the previous flight path. Suddenly they’re gone - only to reappear, if at all, some distance from where one thinks they should be.
As I watched the flight of this butterfly, I noticed a black object that suddenly appeared beside it, following its irregular flight path exactly. I thought of the “Widow Skimmer” I’d just been following. The two objects were within an inch or so of each other, so close I couldn’t tell if there was any contact between them. This parallel flying lasted a second or two, through two or three jinks of the butterfly’s flight. Then, in an instant, the two objects became one, the jinks ceased and the two insects went off in a relatively straight, smoothly descending path arching out over the barley field. I understood the black object, which I assumed to be a dragonfly, had ‘taken’ the butterfly, and was looking for a place to land and eat its prey. After a flight of 15 or 20 feet, the dragonfly landed. It was just within sight and I took the photo at left.
Once again I was struck by the capability of the dragonfly’s brain – this time by its quickness. During the moments of parallel flying, the dragonfly’s reactions seemed instantaneous; there appeared to be no divergence between its flight and that of the jinking butterfly.