“Instinct is a marvelous thing. It can neither be explained nor ignored.” ― Agatha Christie
I’m a big fan of mysteries. As a teenager, I burned through all of Agatha Christie’s classics, and I still love to pick up an occasional thriller that keeps me guessing. As a naturalist, part of my attraction to the outdoors revolves around a different sort of mystery. Science has a lot of answers. But there are many unsolved questions out there.
I like that. Perhaps nowhere is mystery so evident as when I try to understand dragonfly migration.
This week, I’m prepping training workshops for two groups of dragonfly and damselfly monitors at the prairies where I’m a steward. We’re all volunteers, all citizen scientists collecting data that we hope will help future researchers learn more about these incredible insects.
During the workshops, we’ll discuss the life cycle of the dragonfly. It begins with a little rough and tumble dragonfly romance and then, ovipositing or egg laying.
Ouch! That’s got to hurt.
At the two workshops, we’ll share ID tips for differentiating among the 100 or so dragonfly species in Illinois and the almost 50 damselfly species, plus the various variations among male, female, and immature individuals. Pretty straightforward stuff, for the most part.
We’ll touch on the cultural history of dragonflies as well; their use in cuisine, art, and literature. I like this haiku by Basho: “Crimson pepper pod/add two pairs of wings and look/darting dragonfly.” You can see why he was inspired!
Dragonfly cultural history and much of dragonfly natural history is explainable, at least to some degree. But dragonfly migration! That’s where it gets difficult.
Dragonfly migration is less understood than that of the monarch butterfly, whose travel habits have been exhaustively studied, immortalized in novels, and whose migration journey continues to fascinate the general public.
Or consider bird migration, the topic of many books like Scott Weidensaul’s excellent Living on the Wind, and the subject of countless research projects. Sure, there’s still mystery in avian migration. But plenty of information out there.
Dragonfly migration? Not so much. The process remains veiled in mystery. We do know a few things: at least four dragonfly species in Illinois (green darner, black saddlebags, wandering glider, and variegated meadowhawk) head south for the winter, and probably some damselfly species as well.
But why these species? Why not others? Where do they go? What tells them to mass at the end of summer and fly, often in large swarms, to another place?
The Xerxes Society is a wonderful place to discover what we do know about the science of dragonfly migration. As an organization dedicated to protect invertebrates and their habitats, they are a good clearing house for insect migration information. Got some extra time? Click through the link here and read more about how citizen science volunteers are contributing to our understanding about dragonfly migration.
We do know that some dragonflies in North America may travel almost 2,000 miles south in the late summer and early fall. They often join raptors migrating south. Dragonfly offspring will travel the same distances, often with raptors, back north in the spring. Look around in science journals and on dragonfly websites and you’ll find comical images of green darners wearing tiny transmitters to track their movements; or complex studies of isotopes in dragonfly wings which help researchers determine their general place of emergence.
But once you start reading, you realize just how little we know about these dazzling creatures. You get to the end of the dragonfly migration studies pretty fast. It’s a good PhD project for some future researcher! Learning more about what makes some dragonfly species born with an itch to travel.
In April, we’ll begin to see the first battered and worn out dragonflies head north and arrive in the Midwest, heirs of those stalwart flyers who fled south last year. As dragonfly monitors, we’ll scribble about these early arrivals—and later, summer flyers and dragonfly departures—as hash marks on our data sheets. We’ll report the information to staff at our local prairies and natural areas. Then, in Illinois, we’ll upload it to www.illinoisodes.com, our state repository for this information. All very logical and linear isn’t it?
At some point in the season, most of us will put our pencils down and pause for a moment. Overcome with wonder. How amazing that this tiny creature logged those miles and survived birds, weather, and traffic to be here, on this prairie! How incredible that we can bear witness to this phenomenon, even for a moment. How satisfying to be a small cog in the wheel of the research that is being done for the future!
And most of us will acknowledge this: Despite the data we’ll collect, despite all the facts we know, it’s that unknown that makes it so exciting to be a part of this citizen science project. The quest is part of the fun.
And we’ll marvel, in awe of the mystery of dragonfly migration.
Agatha Christie (1890), whose quote opens this post, is the author of 66 mystery novels and 14 short story collections. Her books have sold more than a billion copies in the English language, and just as many in translation. My favorite quote of Christie’s: “The best time for planning a book is while you’re doing the dishes.”
Scott Weidensaul (1959-), who is mentioned in this post, is a Pennsylvania naturalist and writer. My favorite of his books, Living on the Wind, examines the amazing world of bird migration. It was a finalist for the Pulitzer Prize in 2000.
All photos copyright Cindy Crosby (top to bottom): black saddlebags dragonfly (Tramea lacerata), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; eastern amberwing dragonfly (Perithemis tenera), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; ebony jewelwing damselflies (Calopteryx maculata), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; damselflies in tandem, Schulenberg Prairie, The Morton Arboretum, Lisle, IL; violet dancer damselflies (Argia fumipennis violacea), ovipositing in Willoway Brook, The Morton Arboretum, Lisle, IL; calico pennant dragonfly, male (Celithemis elisa), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; meadowhawk (Sympetrum, unknown species), Nachusa Grasslands, The Nature Conservancy, Franklin Grove, IL; monarch butterfly (Danaus plexippus) on butterfly weed (Asclepias tuberosa), International Crane Foundation, Baraboo, WI; great egret (Ardea alba) Nachusa Grasslands, The Nature Conservancy, Franklin Grove, IL; wandering glider dragonfly (Pantala flavescens), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; slender spreadwing (Lestes rectangularis), Nomia Meadows Farm Prairie and wetlands, Franklin Grove, IL; American rubyspot damselfly (Hetaerina americana), Schulenberg Prairie, The Morton Arboretum, Lisle, IL; river bluet damselfly (Enallagma anna), Nachusa Grasslands, The Nature Conservancy, Franklin Grove, IL; blue dasher dragonfly (Pachydiplax longipennis) Schulenberg Prairie, The Morton Arboretum, Lisle, IL; raw data sheet, Schulenberg Prairie, The Morton Arboretum, Lisle, IL; Carolina saddlebags dragonfly (Tramea carolina), Schulenberg Prairie, The Morton Arboretum, Lisle, IL.
If you enjoyed this blogpost, check out some other dragonfly resources at the links referenced above and this excellent blog post from a few year’s ago: Cool Green Science’s “Dragonfly Migration: A Mystery Citizen Scientists Can Help Solve.”
Local friends: If you’re interested in exploring more about dragonflies, join me at Nachusa Grasslands in Franklin Grove, IL, Friday, March 30, 2018 for a dragonfly workshop. Register by e-mailing me at email@example.com.