Dragonfly Monitoring Run

by Carl Strang

On the 4th of July I made my first dragonfly monitoring run of the year, on my assigned stretch of the Des Plaines River at Waterfall Glen Forest Preserve. With a total of 378 individual dragonflies and damselflies tallied, it was far higher than any other count since I took this route beginning in2009. Of course, there was a lot more to enjoy than just Odonata.

A string of great blue heron nests between the boat launch and the start of my route still had some youngsters approaching fledging. Their loud rhythmic guttural calls signaled the arrival of a parent, back from fishing the river.

The carp fence I saw under construction when I last paddled the Des Plaines in the fall is complete. Am I being ignorant or properly skeptical in doubting this will achieve the desired result of keeping Asian carp from moving between waterways?

My thinking, for what it’s worth, is that even if the mesh is fine enough to block tiny youngsters that might slip through at flood stage, there will be breaches from floating logs.

Later, when my run was nearly complete, I encountered this northern water snake.

I was surprised that it seemed undisturbed by my close approach. Then I saw that the eyes were obscured. The snake either was on the verge of shedding, or the scales over the eyes remained stuck when the rest of the skin came off during the last shed.

Entertaining as these sideshows were, dragonflies and damselflies were the main event. Jade clubtails were the most abundant of the 5 species of dragonflies that day; I counted 46 altogether.

Jade clubtails mainly are to be seen perched on objects like this stump.

Common whitetails also were regular sights, some laying eggs.

Here a male common whitetail shares a stump with a bluet and a clubtail.

Most of the individuals were damselflies, however, in 8 species. The largest were a few American rubyspots.

This one was so steadfast that I was able to bring the camera to within a few inches of it.

The largest count of any species was 108 blue-tipped dancers. I didn’t get a photo of any of them, but one of the 82 powdered dancers, a close relative, posed on my deck line.

Such accommodating individuals make identification easy.

The most abundant bluets this time were stream bluets.

The stream bluet is one of the black-type bluets, having a mainly black abdomen.

Stream bluets and hordes of dancers were laying eggs in floating vegetation mats.

The several tandem pairs, perched on the vegetation and laying, may not be as visible here as the unattached and hopeful males hovering above.

I had thought I might do a little fishing on the way back, but the time and mental effort required to identify and count so many insects left me glad simply to paddle back up to the put-in.

October Monitoring Run

by Carl Strang

Last weekend’s warm weather allowed me to make a late dragonfly monitoring run on the Des Plaines River at Waterfall Glen Forest Preserve. Looking back through my records, I find that in all the monitoring I have done since 2003, I never have made a formal outing in October. It was worth trying for that reason, if no other. Besides, it was a nice day to be on the river in my sea kayak. There isn’t a lot to report as far as dragonflies and damselflies go. The only dragonflies were a pair of common whitetails, the female laying some last ditch eggs. I saw a couple familiar bluets,

a few orange bluets,

a stream bluet, 3 eastern forktails and 7 American rubyspots.

The last confirmed that this species is active late in the season, supporting my sighting at Fullersburg (which at first I thought was a smoky rubyspot). I also made some singing insect observations, the best of which were jumping bush crickets singing in the early afternoon on both sides of the river. This adds to my local range for this species, which clearly has shifted north of where you will find it mapped in references. The shallow lagoon at the downstream end of my monitoring area was hosting a gathering of great egrets.

The gorilla in the room, however, was a major construction project underway on the south side of the river. A fence was being built.

With much machinery, much shouting and an impressively speedy progress (I saw no sign of this when I last was there in late August), a metal framework is being erected and filled with fine-meshed screening.

The fence is parallel to the Centennial Trail, which has been closed for this project. The fence is only 6 feet tall or so, enough to disrupt the view of trail users but not enough to be a significant barricade to wildlife, I thought. A little research on the Internet revealed the purpose of this structure. It is a fish barrier. That may seem strange, but high water levels could lift the river high enough to reach the fence. The target fish are Asian carp, a group of 4 species which have been much in the news because of concerns that they might cross from the Mississippi River drainage (which includes the Des Plaines) and the Great Lakes. The Des Plaines River is paralleled by a canal, so the fence apparently is intended to keep the carp from going between the two. Would tiny baby carp be stopped, though? I’m not enough of a fisheries biologist to judge. For more information on the fish species and other information, here is a link.

Mud on the Damselfly, Egg on My Face

by Carl Strang

During the past month, the long awaited Damselflies of Chicagoland by Marla Garrison was published on line. I finally checked it out last week, and was blown away by how excellent it is. If you have an interest in this insect group you really need to become acquainted with this work. As I skimmed through it I noticed that the smoky rubyspot was listed among the species that have not yet been confirmed in the area. Back in 2008 I had photographed a damselfly at Fullersburg Woods that I identified as a smoky rubyspot, and included it in one of this blog’s first posts.

I forwarded the photos to Marla, and she tactfully reminded me that some damselflies, including the rubyspots, submerge themselves completely when laying eggs. Salt Creek is muddy. This in fact is an American rubyspot with a thin coating of mud. Marla noted that the mud had worn off in a few spots, including the ovipositor, which is pale instead of the all black color that would be shown by a smoky rubyspot. I am disappointed, of course, that I need to remove this species from the list of those with which I have some experience, but I have gained knowledge from the episode.

Dragonflies on the Deck

by Carl Strang

I have been part of the regional dragonfly monitoring program since it began in 2003. I started counting dragonflies and damselflies at Willowbrook, Songbird Slough and Waterfall Glen Forest Preserves, in recent years focusing on the last two. Though I continued to find new species from time to time, the past couple of years I have felt the need to try something new. The major gap in my knowledge was in river species, so this year I decided to combine my loves of kayaking and dragonfly monitoring by trying out a river route. Water levels have been high, and cool weather has been suboptimal for monitoring, so I didn’t make my first excursion until last weekend. I launched my sea kayak from the forest preserve boat ramp at Des Plaines Riverway, and headed downstream into Waterfall Glen Forest Preserve.

Des Plaines monitor view b

Experienced kayakers know to tie everything to the boat. I didn’t want to risk wetting my digital voice recorder, so I tied a waterproof notebook to a deck line, tied two pencils to the notebook, wore my waterproof small camera and binoculars, and tucked everything else into my yellow deck bag.

Monitor deck 1b

I used the strongest current in the center of the river to go downstream, taking moments along the way to enjoy sights such as scattered great blue heron nests.

GB heron nest Des Plaines b

The only American rubyspot of the day made it easy by landing on my bow.

American rubyspot kayak b

Dragonflies were tougher, however. The low, seated vantage point made flying dragonflies look different, and it took a while to recognize even familiar species. They were flying fast over the center of the river, making photography impossible, and even tracking them with binoculars was very difficult. My frustration was limited by the low number of insects active in the center of the river that day. I reached a convenient turn around point after an hour, and started back following the sunlit north shore. (Current is slower near the bank, making the upstream paddling easier.) Odonata were much more abundant along the edge. Some damselflies continued to land on the boat. Here a powdered dancer and a blue-fronted dancer chose to land on the deck bag, providing a comparison shot.

Dancers kayak 1b

Other damselflies kept their distance, landing on sticks or debris. The small camera’s telephoto was adequate to get shots of the abundant blue type bluets, which proved to be familiar bluets.

Familiar bluet 5JL 1b

There also were many black type bluets, which I identified as slender bluets.

Slender bluet 5JL 1b

The most abundant dragonflies were jade clubtails, some of which liked my deck.

Jade clubtail kayak b

I was pleased to see a Cyrano darner along the way, though I was unable to get a photo. Toward the end I got a nice view of some Illinois roses.

IL roses Des Plaines b

All in all there was a nice variety of species, most of them familiar but some I missed. I look forward to a continuing learning experience as I return to this route on future weekends.

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