Id like you to take a look at a drawing made by a Darner Dragonfly a Darner Doodle of sorts. Actually, my fingers held the pen but the dragonfly directed my every move back and forth across the page. I tracked his flight pattern for about two minutes, beginning at the lower center and ending at the upper left, before I was worn out. You should know me well enough by now not to ask why I did such a thing, but I will say my effort was an experiment of sorts.
Master aerial predators, all dragonflies seek and pursue their prey by employing their superior flight abilities and eyesight. Probably the most common method is to perch on a prominent branch or twig and fly out to intercept anything that moves. This sortie technique conserves energy and permits an individual dragon to pick up motion anywhere within a 360 degree field of its eyes.
As a group, dragonflies are basically flying eyes. One look at the face of a typical Darner will confirm this observation. (I cant tell you the exact kind of Darner, because the mottled, shadow, common, green striped, black tipped, spatterdock, variable, lake and lance tipped look very similar. It might be a female Green Striped Darner, but lets just look at the eyes for now). They have two huge domes of vision (it hardly seems right to call them eyes) that consist of up to 30,000 faceted eyelets or ommatidium. Youll note the black dot at the center of the eye in the photo. This is where you are actually looking down into the center of a bunch of facets like peering down several well shafts. The dot appears to move as you change your angle, so it seems like the creature is tracking you. You might call this the Mona Lisa effect.
Their field of vision is close to a full circle above, below, to each side and behind even without moving their pliable little necks. Exactly what they see is up to debate. It is believed they dont see clearly focused pictures but process the multiple images into a distinct motion induced view. There is even some evidence that they can see color & polarized light. If our local police force was equipped with a similar set of detection equipment, no one would escape a violation notice.
Once a victim is spotted, this interceptor insect launches into flight and scoops the prey out of the air in its basket like array of legs. It then mashes the quarry into a pulp using a powerful set of toothed mandibles. The order name for dragonflies Odonota basically means Toothed Ones. They often begin the eating process while still on the wing.
The particular Darner dragonfly that I was observing wasnt engaged in the usual sortie type behavior. In short, it didnt seem to be landing at all, but was continuously coursing back and forth. I began tracking it to see if this indeed was the case. After two minutes, my doodle indeed proved such to be the case. Indeedy doodle it did.
Mr. Darner was continuously weaving back and forth over a territory of about 50 feet along an edge where a field met a line of scrub. It concentrated at the very edge of the thicket and only occasionally ventured out over the grass tops. Once it veered skyward to unsuccessfully intercept a passing butterfly but quickly returned to the treadmill. The critter never paused during the whole time and likely would have traveled darn near the better part of a mile had the flight path been straight. For lack of a better term, Ill call this hunting behavior as patrol style and it this was a fun way to document it.
I never captured this hyper individual, but I believe it was a Green Darner. Greens are very common and very large members of the darner clan. Seeing the tremendous output of flying energy exhibited by the patrolling individual, it should be no surprise that this species is capable of migrating for hundreds of miles each fall. They have been shown to move in a steady stream just like birds, but unlike birds their flight is one way.
A recent article on the National Geographic site shows how micro-technology has permitted scientists to attach tiny transmitters to these insects in order to probe the mysteries of this migration. Soon researchers will be able to amass some flight data about the Green Darner and draw some squiggly lines of their own. For now, however, I am satisfied to do it the low tech way with a pen, paper and a few minutes of daylight.
Once Upon A Michigan 
