November 6, 2009 at 7:12 am (birds, botany, dragonflies and damselflies, insects (other), mammals, reptiles and amphibians, singing insects)
Tags: Asclepias, aster, Baltimore oriole, black-capped chickadee, blue jay, blue-gray gnatcatcher, brown-headed cowbird, chimney swift, chipping sparrow, common grackle, downy woodpecker, eastern bluebird, eastern kingbird, eastern phoebe, Erigeron, Eupatorium, European starling, house wren, mallard, Mayslake, northern flicker, Polygonum, Ranunculus, red-bellied woodpecker, red-winged blackbird, robin, Solidago, song sparrow, tree swallow, white-breasted nuthatch
by Carl Strang
Earlier this week I completed my first year of observations at Mayslake Forest Preserve. Many of the posts in this blog, which also is approaching its first birthday, have shared pieces of Mayslake’s ongoing natural history. It’s appropriate to look back at what I have learned there so far. Today I’ll simply share some numbers, the counts of species I have observed on the preserve to date.
Resident vertebrates include 14 species of mammals, 4 reptiles and 3 amphibians (though additional frogs have been observed at Mayslake by others in recent years). The bird species count is 130, many of which were migrants passing through. I saw evidence for successful nests, fledging at least 1 young, in the following 21 species: eastern bluebird, chimney swift, song sparrow, house wren, eastern kingbird, robin, northern flicker, blue jay, eastern phoebe (cowbird produced), chipping sparrow (cowbird produced), downy woodpecker, red-winged blackbird, red-bellied woodpecker, common grackle, black-capped chickadee, tree swallow, European starling, blue-gray gnatcatcher, Baltimore oriole, white-breasted nuthatch, mallard.
The insect species count is only 97 so far, but most of these belong to 4 groups to which I have directed most of my attention: 26 species of singing insects, 29 dragonflies and damselflies, 24 butterflies and moths, and 6 bumblebees.
Likewise my attention to Mayslake’s vegetation has been limited to certain groups of vascular plants. These include 49 trees (including those planted by landowners prior to forest preserve acquisition), 23 vines and shrubs, and 184 forbs. I’ll elaborate the last a little by mentioning genera represented by 4 or more species: so far I know of 4 Asclepias (milkweeds), 6 Aster, 4 Erigeron (fleabanes), 5 Eupatorium (a diverse genus including Joe Pye weeds, bonesets, and white snakeroot), 4 Polygonum (knotweeds), 5 Ranunculus (buttercups), and 7 Solidago (goldenrods).
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October 19, 2009 at 6:02 am (dragonflies and damselflies, geology)
Tags: bedrock, dolomite, Niagara formation, Bruce Peninsula, Hines emerald, Somatochlora hineana, dolomite prairie
by Carl Strang
Bedrock is the kind of stone found closest to the surface at a particular point on the Earth. In DuPage County our bedrock is a sedimentary rock of Silurian age called dolomite, and it belongs to the Niagara formation. A bit over 400 million years ago this part of North America was a reef-dotted shallow part of the world ocean. Over a period of millions of years, precipitates and microscopic shells, along with some larger life forms, settled to the bottom of the sea and built up a layer of sediment that later solidified into limestone, or calcium carbonate. Later, some of the calcium became replaced with magnesium atoms, changing the rock enough chemically that it was less soluble, and worthy of a new name, dolomite.
DuPage County is part of a ring of Niagara formation bedrock that extends up the west coast of Lake Michigan, forms Wisconsin’s Door Peninsula and the southern boundary of the U.P., wraps around the Canadian side of Lake Huron to divide the main lake from Georgian Bay, continues south to form the Bruce Peninsula jutting into southern Lake Huron, and eventually wraps around northern Ohio and Indiana back into northeast Illinois. Niagara Falls pours over an erosion-resistant edge of this formation, which also has outliers in Missouri and Iowa.
A few years ago I drove around Lake Huron. One of my stops was the tip of the Bruce Peninsula. There, the bedrock is at the surface. It’s possible to get a sense of what our landscape might look like in northeast Illinois if it were not covered by glacial deposits. Instead of being surfaced with crushed dolomite, our trails might run over the raw rock.
A trip to the beach would look quite different.
We might find cliffs.
Though dolomite is not as subject to solution and cave formation as limestone, sea caves might occur where waves pound the shore.
We might even find structures like the “flowerpots” that stand on Flowerpot Island off the Bruce Peninsula tip.
But as it is, there are few places in northeast Illinois where the bedrock reaches the surface.
For example, the dolomite prairies near the Des Plaines River offer rare habitat for the federally endangered Hines emerald, a dragonfly that can live only where Niagara formation dolomite provides the right water chemistry for its crayfish-tunnel-dwelling larvae.
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October 15, 2009 at 7:14 am (dragonflies and damselflies)
Tags: autumn meadowhawk, cherry-faced meadowhawk, Mayslake, saffron-winged meadowhawk, Sympetrum costiferum, Sympetrum internum, Sympetrum vicinum
by Carl Strang
It’s nice to solve a minor mystery and, in the process, gain new insights into past observations. I experienced an example of this last week after encountering an odd dragonfly at Mayslake Forest Preserve.
This small dragonfly perching on the trail near May’s Lake clearly was a meadowhawk. The abdomen, though nearly black like the rest of the insect’s body, was mainly dark red in color. I took a number of photos, and though none were perfectly sharp they allowed me to take some time with my reference books and identify it. At first I leaned toward cherry-faced meadowhawk because the dragonfly’s face was dark red, but references insisted that its abdomen should be bright red. I carefully read accounts of all the region’s meadowhawks, and found that male saffron-winged meadowhawks can become very dark with age. In the photos I found that the leading veins of the wings were dark red, the tops of the last abdominal segments were black, and the black edging on the sides of the abdomen was more in the form of a line than a string of large triangle shapes. All these characters confirmed the identification. By now my memory was prompted to go back through some photos from last year, because I remembered seeing a similarly dark meadowhawk. Here is a photo I took at Kettle Lakes Provincial Park in Ontario.
It likewise proves to have been a saffron-winged. But I also found that I had documented another dragonfly of this species at Mayslake.
This last photo, from November, 2008, I took close to the location where I saw the dragonfly last week. It proves likewise to have been a saffron-winged meadowhawk. The meadowhawks as a group tend to be late-season dragonflies, but now I have the impression that the latest of them all are this one and the autumn meadowhawk (the following photo of which I took just before encountering that saffron-winged last week).
This case again vindicates my practice of photographing any dragonfly for which I have any doubt of its species identity.
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October 8, 2009 at 6:04 am (dragonflies and damselflies)
Tags: Aeshna constricta, Aeshna umbrosa, lance-tipped darner, Mayslake, shadow darner, wheel position
by Carl Strang
I didn’t really expect to add any more species to the Mayslake Forest Preserve dragonfly list this year. The wheel of the seasons turns inexorably, and it’s late. But on the last day of September I encountered a different kind of wheel.
There are two dragonflies in this photo. They are in the wheel position, a posture assumed by mating Odonata. The male, above, has grasped the female behind her head with the tip of his abdomen. She has brought the tip of her own abdomen to the base of his thorax, where she is acquiring a sperm packet and completing the wheel shape. These dragonflies clearly belong to the blue darner group of species, so I made an effort to get photos of the sides of their thoraxes and the tops of their abdomens.
The stripes on the sides of the thorax are relatively straight here, with slight but significant wavers in their edges. Spots on the top of the abdomen are relatively large.
These characters point to lance-tipped darner as the species identification. Earlier in the season I found the similar shadow darner, with its distinctively smaller abdominal spots, at Mayslake.
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September 30, 2009 at 5:45 am (dragonflies and damselflies, insects (other))
Tags: Mayslake, common green darner, Anax junius, common milkweed, Asclepias syriaca, dragonfly migration, Carolina saddlebags, Tramea carolina, shadow darner, Aeshna umbrosa, milkweed tussock caterpillar, Euchaetes egle, Chinese mantis, Tenodera sinensis
by Carl Strang
A couple days ago I put a finish on the floral season at Mayslake Forest Preserve. Today I’ll shake a few late insect photos out of the camera. We’ll start with some Odonata.
At Mayslake as elsewhere, hundreds of common green darners paused in their migration to hunt above the prairies and meadows. Migrating south is thought to be worthwhile for them and other large, strong dragonflies as they can extend their breeding season and spread their genes over a larger area. The various saddlebags species also migrate. Here is a UFO shot of a Carolina saddlebags that graced the mansion lawn area one day.
A darner that shows up in a lot of places late in the summer is the shadow darner.
That vertical perching posture is typical. Common milkweeds have been hosting a late-season caterpillar, the milkweed tussock caterpillar.
They are larvae of a tiger moth. I’ll close with a predator. This Chinese mantis assumed a cheerleading pose.
Then, it began to groom its hunting apparatus.
Earlier I showed an egg mass, which is how the species overwinters. Soon all the insects will be going into their various dormant forms to survive the long, cold, dry months of winter.
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September 9, 2009 at 6:10 am (birds, botany, dragonflies and damselflies)
Tags: Arigomphus submedianus, Des Plaines River, dragonfly monitoring, eastern amberwing, Enallagma geminatum, halberd-leaved rose mallow, Hibiscus militaris, jade clubtail, kayak, Perithemis tenera, sandhill crane, skimming bluet, Waterfall Glen
by Carl Strang
Last week I made my fourth dragonfly monitoring excursion of the season by kayak on the Des Plaines River (last updated here ). It was a pleasant, early autumn day. Practically nothing was happening over the center of the river, but there was more action near shore. I found only two dragonfly species. Eastern amberwings remained common, and I also saw a few jade clubtails. Here is one of the latter.
September 3 is a late date for that species. Damselflies were common, and in general were the same species I had seen on the previous outing in early August. The only new species was a tiny skimming bluet, which perched for a time on my deck line.
Otherwise, highlights included patches of halberd-leaved rose mallows,
and the best surprise of all, a single sandhill crane hunting in one of Waterfall Glen’s marsh streams.
I hope to get on that river at least one more time this year.
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August 5, 2009 at 6:07 am (dragonflies and damselflies)
Tags: Des Plaines River, eastern amberwing, Enallagma exsultans, Enallagma signatum, Enallagma traviatum, kayak, orange bluet, Perithemis tenera, slender bluet, stream bluet, Waterfall Glen
by Carl Strang
Earlier I described my first venture into dragonfly and damselfly monitoring by kayak. I have been out on the Des Plaines River twice since then. There has been some variation in the count of species and individuals each time, but most seems unremarkable. I’ll focus on a couple high points. The biggest surprise was a transition in the damselflies. The slender bluet was the common black type bluet my first time around.
Bluets are a group of small to medium sized damselflies. Black type bluets are so called because their abdomens are nearly all black as viewed from above. On my second and third outings, the slender bluets were replaced by stream bluets as the common black type bluets. Here is one of the latter I rescued from the water.
Note that, in contrast to the slender bluet in the top photo, the stream bluet has a slender blue shoulder stripe with a wider black stripe below it. “Eye spots” on the back of the head are smaller in the stream bluet, and there is less blue in the abdomen tip. Stream bluets were largely in tandem pairs and actively laying eggs on floating vegetation during both recent outings.
The other surprise is the relatively large number of orange bluets. Here is one sharing a photo with a stream bluet.
I’m not saying that the river is swarming with them, but in my experience a count of 13 orange bluets in a 2-hour outing is a lot. A final note is that eastern amberwings have become the most abundant dragonflies, despite my seeing none on the first outing. Here is a photo of one from 2007.
I have decided to limit my monitoring to the stretch of river that bounds Waterfall Glen Forest Preserve. This gives me a span of stream between the launch ramp and the preserve in which I can practice another type of inquiry, to be featured tomorrow.
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July 24, 2009 at 6:13 am (dragonflies and damselflies)
Tags: emerald spreadwing, four-spotted skimmer, Lestes dryas, Lestes unguiculatus, Libellula pulchella, Libellula quadrimaculata, lyre-tipped spreadwing, Mayslake, ruby meadowhawk, Sympetrum rubicundulum, twelve-spotted skimmer
by Carl Strang
Some time has passed since I last updated dragonfly and damselfly appearances at Mayslake Forest Preserve, and a few more species have added themselves to the roster. I have seen several four-spotted skimmers.
This species seems to be abundant in some years, scarce in others. According to reports I’m hearing, Mayslake is joined by many other northeast Illinois locations in having a good emergence year for 4-spots. The following meadowhawk was the first mature red male I have seen this year. He kept his face hidden, so I did not get his identity, but in nearly the same spot I saw a ruby meadowhawk a few days later.
The meadowhawk sought flying insects, when as you can see there were a lot of red aphids for the picking, on the same perch. I also encountered a couple new spreadwing damselfly species. This emerald spreadwing, with its metallic green body, is not done justice by this photo.
New not only to Mayslake’s list, but also to me (a “lifer” in birder parlance) was this lyre-tipped spreadwing.
So far I have seen two of these in different parts of the preserve. I’ll finish this update with a photo of a female 12-spotted skimmer.
I’ll be surprised if more species do not show up before the end of the season.
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July 9, 2009 at 6:27 am (dragonflies and damselflies, methods)
Tags: American rubyspot, Argia apicalis, Argia moesta, Arigomphus submedianus, blue-fronted dancer, cyrano darner, Des Plaines River, Des Plaines Riverway, dragonfly monitoring, Enallagma civile, Enallagma traviatum, familiar bluet, great blue heron, Hetaerina americana, Illinois rose, jade clubtail, kayak, Nasiaeschna pentacantha, nest, powdered dancer, Rosa setigera, slender bluet, Songbird Slough, Waterfall Glen, Willowbrook
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.
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.
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.
The only American rubyspot of the day made it easy by landing on my bow.
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.
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.
There also were many black type bluets, which I identified as slender bluets.
The most abundant dragonflies were jade clubtails, some of which liked my deck.
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.
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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June 23, 2009 at 6:31 am (dragonflies and damselflies)
Tags: 12-spotted skimmer, Argia apicalis, Arigomphus submedianus, blue dasher, blue-fronted dancer, common baskettail, common spreadwing, eastern forktail, Enallagma civile, Enallagma signatum, Epitheca cynosura, Epitheca princeps, familiar bluet, Ischnura verticalis, jade clubtail, Lestes disjunctus, Lestes rectangularis, Libellula pulchella, Mayslake, orange bluet, Pachydiplax longipennis, prince baskettail, slender spreadwing
by Carl Strang
The weather has been rainy, gloomy and cool on many recent days, but when the sun appeared so did the insects. At Mayslake Forest Preserve I have been able to add new species and observations that provide a foundation for future study. Eastern forktail damselflies already have been busy laying eggs in May’s Lake.
Meanwhile, other damselflies are emerging. The next two photos are, I believe, of common spreadwings, a male
and a female.
Having newly emerged, they are holding their wings together more than usual. Another spreadwing species is the slender spreadwing.
Note the contrasting pale veins of the wingtips. Another, blurry photo established that the abdomen has the characteristic length, twice that of the wings. I have seen orange bluets at both of the preserve’s lakes.
Familiar bluets also have begun to appear.
The year’s first blue-fronted dancer was a female.
Its abdomen is dark, including the sides of the tip, and has only a very narrow pale line down the top. Shifting now to dragonflies, I’ll start with a 12-spotted skimmer that began patrolling the stream corridor marsh in June. I expect the species to be common there. This one I photographed elsewhere in 2004.
Blue dashers have been active out in the fields, and soon will be appearing at lakes and marshes.
A jade clubtail has staked out a piece of the May’s Lake shore.
Cruising farther out are the prince baskettails. Here is a UFO-ish shot of one.
And here is a common baskettail showing the basal wingspots that are visible on some, but not all individuals.
A final, cautionary photo:
This is not an orange bluet, but a newly emerged female eastern forktail. Note the absence of the orange at the abdomen tip plus the expanded orange area at the base of the abdomen.
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