Dragonflies reveal amazing secrets to Northwoods citizen scientists
Since childhood, Val Burns has been fascinated with insects. So, when she discovered that the Wisconsin Department of Natural Resources needed help with their dragonfly survey project, she signed up.
“Actually, I was really just looking for something to do with my teen-aged daughters,” she says. “The DNR has a number of projects that families can get involved with, and this seemed like a fun thing to do together while spending time outside.”
Daughter Rachel, 13, took to it right away, and the mother/daughter duo is in their second year of finding, identifying and documenting the mighty hunters. “We’ll just grab the net, throw the guidebook, a notebook and magnifying lens in a backpack and we’re ready,” says Val. “Running errands, we’ll watch for a likely field or lake shore, stop and look for dragonflies.”
Their own yard has proven a fantastic place to observe the insects, too, but that is by design. Val grows insect-friendly plants in her gardens and makes sure to leave patches of tall grass and wildflowers in the lawn as a haven for dragonflies. “Some of them perch vertically on tall stems,” she explains. “Many of them like to land and sit on flat stones on the ground. I’ve left some dead branches on the bushes because that seems to be a favorite resting spot for some other species.”
The fact that each species emerges at a set time during the summer makes identification a bit easier, according to Val. “Last year we did pretty well learning the names and spotting the different ones,” she says. “Over the long winter, that all seemed to just fly out of my head, but we’re getting back into it again.”
Bob Dubois, DNR research scientist and aquatic systems ecologist, heads up the dragonfly survey, and is glad to have Val, Rachel and the hundreds of other “citizen scientists” helping out. “To find out more about dragonflies, we need eyes out there who know what they’re looking at,” he says.
“About half my job is working with our volunteers,” he continues. “I travel around doing classes and workshops, going on group outings and meeting the great folks who help us out. We started the survey 12 years ago, but found it difficult to monitor the whole state with agency staff.”
Resources for volunteers include numerous websites such as the Wisconsin Dragonfly Society and various online guides, but the most helpful seems to be the society Facebook page where volunteers post photos, ask questions and compare notes.
“It’s a great place for beginners to look at the dragonflies others are seeing,” says Bob. “They can ask questions and get gentle feedback from more experienced volunteers. It’s a very popular site with over 300 members.”
The actual reporting is quite easy to do, according to Bob, and includes listing species spotted along with specific locations and dates. If volunteers aren’t sure of exactly what species they’ve seen, they can upload a photo.
Eventually, collation of the survey data will tell Bob and other researchers just what habitats are needed by which species, and track populations over the years. “There are 162 species of dragonflies and their smaller cousins, the damselflies, in Wisconsin,” he says. “That approaches the number of different bird species that we have. Dragonflies breed in a kaleidoscope of aquatic areas from ponds and lakes to bogs and shallow marshes.”
Lifecycle of the Odonata
The family of dragonfly-like insects, called Odonata, includes more than 5,000 different species worldwide. Fossil evidence of giant individuals living thousands of years ago attests to the success of these insects.
The fact is, the popular idea of a dragonfly with flashy wings and big eyes represents only a small part of the insect’s life. Upon hatching from an egg, the larvae, known as a nymph, lives, breathes, eats and grows under the water.
“When you look at the lifecycle, they spend 90 percent of their lives under water,” Bob says. “That phase can last from one to two or even four years. They do best in quiet water with lots of sticks, leaf packs and muck.”
Nymphs are ferocious hunters, too, eating just about anything they can catch. They prey on other aquatic insects (including fellow dragonfly larvae), worms, small fish and tadpoles. They gobble up mosquito larvae as well.
Lacking the wings that will later make them masters of the sky, nymphs utilize a jet-propulsion system in which they force water through their anal opening to give them a burst of speed to catch their underwater prey.
In spring, the nymph climbs out of the water, usually on to a plant stem. Its shell cracks along the back, allowing the insect to slowly climb out, unfold its four wings and perch in the sun to dry.
Val says she has been lucky enough to witness this event several times. “They have such a beautiful look when they first emerge,” she says, “glistening and soft with those delicate wings.”
Val and Rachel also look for the abandoned shells that remain after the dragonflies emerge, called exuvia. “They look kind of creepy,” says Val. “We’ll find them on tree branches and logs, sometimes in groups piled right on top of each other. It seems the larger ones are usually further from the water. We collect them, noting exactly where and when we found them, and send them to Madison for identification.”
Since dragonflies can travel long distances on their glorious new wings, the exuvia are very valuable in determining which water bodies are supporting the nymphs. This is helpful, as mitigation practices around the state create new wetlands when others are destroyed. The winged insects are adept at finding these new places to lay their eggs as long as the conditions are right.
The dragonfly hatch this past spring was quite late due to the cold weather, says Val. “Everybody remembers how bad the mosquitoes were,” she says, “and we were all just waiting for the dragonflies to come out. Once they did, we noticed the difference right away; they are good hunters.”
Mosquitoes are not dragonflies’ major prey, though. Just as they did as nymphs, they will eat just about anything they can catch. Mostly, according to Bob, they end up with nonbiting midges.
“They hunt in bright sunlight,” he explains. “And, of course, mosquitoes usually are found in shady, cooler areas. Dragonflies rarely get into the areas where mosquitoes are thickest, but they will gobble up anything at the edges of its hunting grounds.”
Each dragonfly has about 30,000 eyes that let it sense movement in any direction. It can fly up, down, backward or forward or even hover in midair.
Its wings have ridges which catch even the smallest movement of air, allowing it to out-fly just about anything else around. Then the dragonfly will capture an insect by making a basket shape with its six legs and consume it on the spot.
Butterflies, other dragonflies, moths, mayflies, bees and wasps often fall prey. Beekeepers are not fond of the hunters, which can devastate a hive in a short time. Dragonflies have been known to eat their own weight in insects in under 30 minutes.
Time is short for the flyers, which have only a few weeks to hunt, avoid predators, find a mate and lay eggs. Some of next year’s dragonflies are already hatching out under the surface of Northwoods lakes and wetlands, ready to hunt and grow under the ice until the warm spring sunshine calls them to the sky.
Now is the perfect time for anyone interested in learning more and helping with the dragonfly survey to start exploring. Visiting the Wisconsin Dragonfly Society website (wiatri.net/inventory/odonata/WDS/) and Facebook page is a great way to dive right into the life of the Odonata.
Sue Schneider is a freelance writer who lives in Rhinelander. Her articles also appear in Northwoods ‘boomers and Beyond and Northwoods Commerce magazines.
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