Dragon Hunting on the St. Croix

Dragonflies and damselflies are beautiful, highly-specialized hunters, and fun to watch.

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You’ve probably noticed dragonflies and damselflies zooming along the St. Croix River, but have you stopped to take a closer look?

A growing number of people are catching the “Odeing” bug. Odonata is the order name for dragonflies and damselflies. Dragonflies hold their wings out flat like an airplane, have meaty bodies, are strong fliers, and have eyes that almost always touch. Damselflies mostly hold their wings folded up over their abdomens, have more petite bodies, are fluttery fliers, and have well-separated eyes like a hammerhead shark.

Dragonflies have eyes that touch (most of the time) and meaty bodies.
Dragonflies have eyes that touch (most of the time) and meaty bodies.
Damselflies hold their wings up over their backs, have a petite bodies, and well separated eyes. Photo by Jon Thompson.
Damselflies hold their wings up over their backs, have a petite bodies, and well separated eyes. Photo by Jon Thompson.

Dragonfly watching has the same appeal as birding with a few extra bonuses:

  1. Dragonflies and damselflies prefer to fly during the heat of the day. So those of us late sleepers can have a leisurely breakfast and second cup of coffee before hitting the field at peak dragonfly time.
  2. Only about 150 species of Odonata call the north woods home. That’s enough to keep the hunt interesting but not overwhelming.
  3. The likelihood of finding a new species never before recorded in your county is quite good. Odonata haven’t yet been thoroughly surveyed and active enthusiasts can make significant scientific contributions. (County species lists and record submission forms can be found at www.odonatacentral.org.)

Surprisingly, dragonflies spend most of their lives underwater as aquatic nymphs. Depending on food and water temperature, nymphs may live one year or a few years underwater. When ready to metamorphose into an adult, a nymph will crawl out of the water and up a plant stem. The skin along its back busts open and a shriveled version of an adult body wiggles out. Its wings and abdomen slowly inflate with air and blood until it is completely transformed. A paddler with a keen eye can spot old skin casts clinging to shore land plants.

Freshly emerged adult dragonflies. Photo by Ami Thompson.
Freshly emerged adult dragonflies. Photo by Ami Thompson.

Adult dragonflies and damselflies have one major goal: reproduction. Males claim a female for mating by grabbing her head with claspers at the end of their tails. They fly around like that in “tandem” before and after they mate, often landing on the gunwale or paddle of the unwary canoeist. Copulation occurs when the female curves her abdomen under to connect with his secondary reproductive parts on his belly behind his wings. This position is called “wheel.” Some sentimental folks say it looks like they make the shape of a heart.

Dragonflies in the copulation wheel. Photo by Jon Thompson.
Dragonflies in the copulation wheel. Photo by Jon Thompson.

The ladies are able to lay eggs pretty much immediately after they mate. Most males will guard her while she lays either by continuing to hold on to her head with their claspers or by hovering over her and chasing away any other males that venture too close. If another male where to swoop in and grab her before she finishes laying the interloper could mate with her and displace the previous male’s genetic investment.

Identifying a dragonfly using a guidebook. Photo by Dudley Edmondson.
Identifying a dragonfly using a guidebook. Photo by Dudley Edmondson.

Identification of most species can be done with careful naked-eye observation or close-focusing binoculars in combo with a good field guide. However, it is often very helpful (and fun!) to catch and hold them for a closer look. Capture them with a solid swing in an aerial insect net.

It is safe (for you and for them) to hold them either by all four wings folded up over their backs or by three or more legs. Larger dragons have mouthparts than can pinch skin – it’s only sporting for them to have some way to object to being held! They are not able to sting.

Holding a dragonfly by the wings. Photo by Ami Thompson.
Holding a dragonfly by the wings. Photo by Ami Thompson.

Catching a dragonfly is tricky and requires tenacity. They are nearly all eyes and wings. Their eyes are the most complex in the insect world and allow them to see in all directions and all colors (including UV and polarized light). Their wings are connected to gigantic muscles that work independently so they can fly in all directions, including straight up and backwards.

These adaptations have created perhaps the most efficient hunter in the world: they capture more than 90% of the prey they go after. In exchange for these specializations, Odonata have sacrificed a sense of smell, hearing, and the ability to walk – their legs are only strong enough to perch.

Ami Thompson Odeing on the St. Croix River. Photo by Jon Thompson.
Ami Thompson Odeing on the St. Croix River. Photo by Jon Thompson.

Earlier this month my husband and I slipped our beloved Minnesota II canoe into the St. Croix at Interstate State Park and floated down to the Osceola Landing. Hugging the shore we spotted river-loving damselflies including the American Ruby-Spot (Hetaerina americana), Ebony Jewelwing (Calopteryx maculata), Blue-fronted Dancer (Argia apicalis), and Powdered Dancer (Argia moesta). We also noticed that Black-shouldered SpinyLeg (Dromogomphus spinosa) dragonflies were hanging out in the sunny and eroded sandy areas on the east bank.

We optimistically kept a keen out for the rare St. Croix Clubtail (Ophiogomphus susbehcha), a new species recently discovered on the St. Croix that is federally threatened and endangered in Wisconsin. However, our efforts were not rewarded. Perhaps our timing was a little off or our luck a little dry but it makes for a good excuse for another future trip!

Opportunities to learn more:

Saturday, August 17th: I will be leading a free dragonfly bioblitz hike at 10:00 am at Tamarack Nature Center in White Bear Lake, Minnesota. This FREE event is sponsored by the Vandais Lakes Area Water Management Organization. All supplies will be provided. Email me to register: ami@amithompson.com.

Saturday, October 5th: I will be leading a mid-day talk and field outing to explore fall Odonata at Crex Meadows Wildlife Area in Grantsburg, WI from 10:00 am – 1:00 pm during their Fall Festival. This may be your last chance of the year to catch and hold a dragonfly! $15/adult (kids are free). In the case of rain, we’ll examine pre-caught living dragonflies, preserved specimens, and learn how to raise pet dragonfly nymphs during the winter.  Pre-register with me (ami@amithompson.com) or just show up. Space is limited.

About Ami:

Ami Thompson has been a naturalist for 15 years, working first as a Naturalist for the Wisconsin DNR, then for the Minnesota DNR, and finally as a National Park Ranger at the Mississippi National River and Recreation Area. Since 2008, she has run her own environmental education consulting business specializing in educator professional development workshops and interpretive writing.

Ami is a Minnesota Dragonfly Society board member and has written a Dragonfly Curriculum Guide for teachers, naturalists, and parents with instructions and handouts for 17 hands-on dragonfly activities

Learn more at www.amithompson.com.


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Dragon Hunting on the St. Croix