dragonflies and damselflies, with dennis paulson
SOME SPECIES MIGRATE to warmer wintering grounds, and oh, how deftly they do fly—whether on their way south, or on the hunt for supper, or perhaps to meet up with that someone special, and mate in mid-air. But I’m not talking about some feathered creature with a mere single set of wings; I’m talking about dragonflies—as I did in a radio segment and podcast with a leading American expert on the subject, zoologist, Princeton Field Guide author and photographer Dennis Paulson. Share in the four-winged wonder.
UNTIL I MET Dennis Paulson, thanks to the series I’ve been doing with the BirdNote public-radio program he contributes to, I was probably your average dragonfly semi-observer: I knew what they were, but had never really looked too closely.
I quickly ordered the Eastern version of Dennis’s two-volume Princeton Field Guide to dragonflies and damselflies. Before I’d even reached the 336 species-by-species accounts that start on page 49, many of them illustrated with Dennis’s photos, everything in the way I looked at these insects had changed. Already, I was paying better attention and have been able to distinguish four distinct species in the garden, and counting.
Ph.D. zoologist Dennis Paulson is also a keen gardener, and an expert on birds. He directed the Slater Museum of Natural History at the University of Puget Sound in Tacoma, Washington, until retiring in 2004.
“I started with birds, as so many people do,” he says of his interest in nature and science, “and I got interested in everything along the way—insects and flowers and snakes and fish. At one point I was casting around for a Ph.D. dissertation, and realized I didn’t know as much about dragonflies as I would have liked to. I’ve sort of been studying them ever since.”
Today Dennis continues that work in particular as part of the steering committee of the Migratory Dragonfly Partnership (more on that below, including a link to a free downloadable color mini-field guide you can use to get started in your own odonate-awareness journey). But first, our Q&A. There’s more in the podcast than I’ve shared below, so be sure to listen in, too.
the dragonfly q&a with dennis paulson
Q. The world of dragonflies seems to have a language of its own—for instance, I learned that I can call you an odophile, Dennis, for instance. What does that mean?
A. That’s actually a very new word that’s been coined in recent years since so many amateurs have become interested in dragonflies. People who study butterflies are Lepidopterists (and they call them “leps”)—so this was like that.
Someone—I don’t really even know who—came up with the term “ode,” which of course we know as a different thing entirely. But “odes” became short for odonates [the taxonomic order Odonata, to which dragonflies and damselflies belong].
As for where that word came from: It might even be a misspelling of odontology—as in odontologist, the people who study teeth—at least that’s the thought. Someone, perhaps even Fabricius [a student of Carl Linnaeus who specialized in insects in the 18th century], apparently said long ago that these are toothy animals, and they chomp down on their prey, so let’s name them after their teeth.
Q. What’s the difference between a dragonfly and a damselfly?
A. They’re very different creatures, and two different suborders of the order Odonata.
Dragonflies are on average bigger, bulkier, more robust, with larger eyes that are usually touching or not very far separated on their heads.
Damselflies are smaller with a much more slender abdomen, usually, and much smaller eyes that are separated by quite a bit on their heads. Most damselflies that you see will have their wings folded over their abdomen, and most dragonflies hold their wings out once they’ve hardened up as a mature adult. (The spreadwing damselflies are an exception, and can be a little confusing.)
Basically they’re the same animal, though, in terms of behavior. Everything they do is pretty much the same: They’re all predators; there’s not a vegetarian in the crowd. All of the American species breed in the water, so that’s of course where we usually see them.
Most of the ones you see at the water are males. The reason they come to the water: to look for females. The females are at the water because that’s where they have to lay their eggs [as in the top photo]—the larvae, or nymphs as they are called, live in the water. That’s why the odonates’ whole circle of life focuses on freshwater wetlands.
Q. I was startled by the revelation that some species migrate. Can you tell us about that?
A. We actually don’t know much about it. We’ve formed an international group called the Migratory Dragonfly Partnership—and we’re trying to learn more through citizen science and have observers all over North America helping us, recording when they see.
We do know that common green darners [top photo], for instance, are well documented as long-distance migrants much like birds, except that there are two generations involved: the ones that fly north in the spring are the offspring of the ones that flew south in the fall.
[About 16 North American species are known to migrate; profiles of the best-known ones can be downloaded here in pdf format.]
Q. Who eats dragonflies, and who do they eat?
A. Birds eat them—and some birds almost specialize in them. Merlins and kestrels are among the birds that eat a lot of dragonflies, and Mississippi and swallowtail kites actually follow swarms of dragonflies during their migration south.
Larger dragonflies eat smaller ones; frogs catch them near the water; spiders and lizards and robber flies eat dragonflies, and fish eat their larvae.
Besides eating smaller dragonflies, dragonflies eat other insects (including mosquitoes).
Q. Can we as gardeners attract dragonflies?
A. Putting a pond in your yard is the best way to attract dragonflies. Putting vegetation in it is helpful, too, since some species deposit their eggs in plants, but not so much that it chokes the pond; leave open water. Very important: don’t put fish in the pond, since again–fish eat dragonfly larvae.
more fun dragonfly facts
- There are 472 odonate species in the US and Canada and about 6,000 in the world.
- Sussex County, New Jersey, so far has the most dragonfly diversity in the nation, with 145 species observed there.
- The Eastern portion of the nation generally is richer in terms of dragonfly diversity, because it’s got more wetland.
- Besides their head and thorax (the thorax is the locomotion center, says Dennis—where wings and legs are centered), odonates have a 10-segmented abdomen–home of their reproductive parts, and also meaning they are capable of incredible contortions. A mating pair (that’s a darner pair copulating, above) may even form a circle or a heart shape, for instance.
- Much of a dragonfly’s lifetime is spent in the larval, or nymph, stage, where it may molt 10 or a dozen times, each time pushing off its exoskeleton. (Get “Four Wings, Will Travel,” a color pdf introduction to the natural history of the odonates, from the Migratory Dragonfly Partnership.)
- Odonate eyesight is unparalleled in the insect world. A large darner dragonfly can have up to 12,000 to 15,000 simple eyes within each compound eye on its head, says Dennis, and can detect movement, color, and their own species—even sighting them far overhead while in flight. (That’s a striped meadowhawk, below; look at how big the eye is.)
- They don’t just perch, but also “obelisk,” a tactic for what’s called thermo-regulation. Like all other things that are cold-blooded, the odonates get their temperature from the environment. “So if they sit in the sun, they warm up—and you may seem them perfectly aligning themselves perpendicularly to the sun’s rays in the morning, getting warm, maybe on a white wall or a tree trunk, taking in the maximum rays,” said Dennis. “As the day goes on it may become too warm for them—and they may go into the shade, or in some cases they can point their abdomens straight up toward the sun, so they receive the minimal amount of sun rays by doing that.”
- Migratory species may travel hundreds to thousands of miles, at a rate of up to 90 miles a day.
learn more, or get involved with odonates
- Order Dennis Paulson’s “Dragonflies and Damselflies of the East” or “Dragonflies and Damselflies of the West,” from Princeton University Press (disclosure: Amazon affiliate links)
- Visit the website of the Migratory Dragonfly Partnership
- Download a free color field guide to take outdoors with you
- Subscribe to their Citizen Science Newsletter
- Browse the dragonfly article archive on Dennis’s Northwest Nature Notes blog
prefer the podcast?
DRAGONFLIES were the topic of an edition of my weekly public-radio program with guest Dennis Paulson. Listen anywhere, anytime: Locally, in my Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) region, “A Way to Garden” airs on Robin Hood Radio’s three stations on Monday at 8:30 AM Eastern, with a rerun at 8:30 Saturdays. It is available free on iTunes, the Stitcher app, or streaming from RobinHoodRadio.com or via its RSS feed. The June 10, 2013 show can be streamed here now. Robin Hood is the smallest NPR station in the nation; our garden show marked the start of its sixth year in March 2015.
win the princeton guide to dragonflies
I’LL PURCHASE TWO COPIES of Dennis Paulson’s dragonflies and damselflies field guides, part of the Princeton Field Guides series (matching them to the winners’ locations, whether East or West editions), to share with you. (Update: The giveaway ended; thanks to all for participating.) All you have to do to enter is answer this question:
Do you know the names of any dragonflies or damselflies, and do they visit your garden?
(Don’t be shy; I just learned my first couple of IDs recently.)
I emailed two winners, who were drawn at random after entries closed at midnight on Monday, June 17, 2013. Good luck to all!
(Dragonfly photos copyright Dennis Paulson.)