The Hine's Emerald Gallery Page 3

Field Notes

Most of the field work related to this website was carried out along the trails and swales of The Ridges Sanctuary and in the nearby wetlands. A favorite site is Solitude Swale, shown at the left. Although Hine's Emerald dragonflies are sometimes seen here, it is better known for an abundance of Chalk-Fronted Corporals (Ladona julia) and Canada Darners (Aeshna canadensis) in June and August, respectively.

Springs in the area, along with snow and rainfall, ensure that the wetlands generally remain wet. Hine's Emerald larvae survive best in cool, slowly moving sheets of pure water flowing over bedrock of limestone, and it is the calcium carbonate leaching from the dolomite bedrock that provides the calcium-rich environment required by larvae.

The summer of 1999 was a banner year for Hine's Emerald dragonflies at The Ridges Sanctuary. The first Hine's Emerald was seen on June 6, along with hundreds of Chalk-Fronted Corporals, and the last one was spotted August 19. On July 25, near dusk, a feeding swarm of Emeralds was videotaped along the Lake Michigan shoreline next to Sanctuary land. It was estimated that over 100 Emeralds, mostly S. hineana, were in the swarm, along with some Brush-Tipped Emeralds (S. walshii).Five species of Emeralds have been seen in and around The Ridges Sanctuary. In addition to the Hine's and Brush-Tipped Emeralds, S. williamsoni (Williamson's Emerald), S. kennedyi (Kennedy's Emerald), Dorocordulia libera (Racket-Tailed Emerald), and Cordulia shurtleffi (American Emerald) are seen in the area. 

Some effort was expended attempting to obtain images of the Hine's Emerald in flight. Only modest success was obtained with a video camera, and even less with a still camera and telephoto lens. On an early field trip to videotape S. hineana in flight, one perched on the edge of the lens hood of the video camera and just sat there. In retrospect, this should have been taken as a warning about the frustration that was yet to come in trying to videotape such aerobatic dragonflies. The above image is a still photograph of a female Hine's Emerald in flight, with the legs folded against the thorax to increase the insect's aerodynamic properties. The video recordings showed the aerobatic range of these dragonflies, and sequences showed S. hinana doing barrel rolls, inside and outside loops, extremely tight turns, immediate stops to hover, backward flight, and stall outs as they failed to intersect flying prey approached from below.

During the year 2000 season, the Hine's Emeralds didn't appear as abundant at The Ridges Sanctuary as in 1999. Nevertheless, during the months of July and early August, some were always seen. Dragonflies are best seen on warm, sunny days, for sunlight is required for them to efficiently visualize and capture flying prey.

The highlight of the 2000 season occurred on July 14, when a dragonfly workshop group from The Ridges Sanctuary hiked along Lake Michigan to visit a wetlands area along the north edge of the Sanctuary. As the group walked along the beach sedges next to the treeline, literally hundreds of Hine's Emerald dragonflies were encountered. The group was literally surrounded by them as they fed on other flying insects. Feeding dragonflies were seen over a distance of about a quarter mile of shoreline. It was estimated that there were at least 1,000 dragonflies in the swarm, mostly S. hineana.

In walking the trails at The Ridges Sanctuary, it is probably an understatement to note that many, many perched dragonflies go unnoticed. The shape of their body allows them to easily blend in with nearby twigs and stems, especially if the dragonfly is seen from the side, when the insect itself appears twig-like. At the right, for example, the large photo shows a Hine's Emerald dragonfly almost hidden in the vegetation. The inset is an enlarged view of the insect. After a few hours of looking for perched dragonflies to photograph, it's easy to develop eyestrain.

During the year 2000 season a male and a female Hine's Emerald were seen roosting side-by-side in the lower branches of a fir tree along one of the Sanctuary's trails. The sighting was early in the morning, and there is no way of knowing whether they had roosted all night long within a wingspan of each other. The photograph below shows the pair. In three years of observing S. hineana, a pair perched so close together had never been seen. The male is on the left, the female on the right.

Spring was slow in coming, and May was a wet, cool month. On May 30 the water temperature in the swales was around 10 degrees C (52 degrees F). Early June started off wet and cool. The first S. hineana was seen at the Ridges on June 8 (last year it was June 6). As expected, it was a female. Thereafter more females appeared along the trails, all with rusty brown eyes. By mid-month males were appearing and on June 22, a clear, warm day, 12-15 S. hineana were seen feeding over an open area along Deerlick Trail. A couple of days later they were still feeding in this area, and the group included not only S. hineana, but also S. williamsoni, S. walshii, and S. kennedyi (listed in order of apparent number). Also saw Dorocordulia libera, the Racket-Tailed Emerald, which had bluish-green eyes. No mating behavior was observed. It may be that the emerald-green color is related to reproductive maturity in S. hineana and other Emeralds, with the color signaling members of the opposite sex when they are ready to mate. Later, by mid-July, all S. hineana will have their deep, beautiful, emerald green eyes.

Field Notes For July And Early August, 2001

The many clear, hot, and humid days of July made for splendid dragonfly watching at The Ridges Sanctuary, as long as one could tolerate the deerflies and mosquitoes. July roadkill of Emeralds, especially S. hineana, was extensive. Along a one-mile stretch of Highway 57 bisecting a wetlands area just north of Baileys Harbor, each mid-July morning up to a dozen Emeralds could be seen, with their wings sticking up from the asphalt to mark their demise. A few were still alive, with their beautiful emerald eyes beginning to dim. No doubt thousands of dragonflies are clobbered by vehicles in Door County. It's regrettable that so many S. hineana, an endangered species, are lost this way.

A dry July resulted in a drop of water level in swales of the Sanctuary. In some swales, there were only damp spots remaining among the sedges and reeds. One wonders about the impact of such dry conditions on dragonfly abundance three or four years from now, when larvae emerge from this season's egg-laying. Which species will be most affected?

Dan Soluk and his group of researchers from the Illinois Natural History Survey have shown that living larvae of S. hineana are often present in significant numbers in crayfish burrows. Soluk believes that the chances of larvae surviving a dry summer (or a severe winter?) are enhanced by camping out in columns of water at the bottom of crayfish burrows. Since crayfish are known to prey on dragonfly larvae, how S. hineana larvae survive in their burrows is an unanswered question. Larvae would seem to be the perfect dinner guest for a hungry crayfish.

Wetlands are scattered all over the upper two-thirds of Door County, and it's likely that S. hineana will be found throughout the area. How far they range is still anyone's guess (a mile and a half or so is an easy but probably inaccurate answer). Again this summer large aggregations (swarms) were seen feeding on small flying insects adjacent to Sanctuary property along the Lake Michigan shoreline. Near the tree line bordering the beach, for a distance of about 500 yards, it was estimated that 300 Emeralds were feeding, generally flying 4-15 feet above the ground. Quite a sight. This is the same stretch of beach where an estimated 1,000 Emeralds were seen foraging on the same date last year (July 12th). Most of these appeared to be S. hineana.  The Brush-Tipped Emerald (S. walshii) and Williamson's Emerald (S. williamsoni ) were present in lesser numbers. Pantala flavescens (Wandering Glider) and Libellula pulchella (Twelve-Spotted Skimmer) were also seen, along with numerous Meadowhawks (Sympetrum sp). The estimates of numbers of Emeralds were made by participants in a dragonfly workshop group.

S. hineana was seen and confirmed in many new places in Door County, including the Mink River area, the front and back yards of a resident living on top of the bluff in Ephraim, a fen near Sturgeon Bay, in the Ephraim Wetlands Preserve, and in meadows near the wetlands complex that extends across the peninsula from Ephraim to Baileys Harbor.

By early to mid-August at the Sanctuary, S. walshii was present in abundance, and Aeshna canadensis (The Canada Darner) was becoming more and more abundant along the trails and swales. When it comes time to lay eggs, it appears that some dragonflies may have a preference for one swale over another. As an example, Solitude Swale is a center of reproductive activity for Ladona julia (Chalk-Fronted Corporal). S. walshii is often seen laying eggs in Sandy Swale, and a little later A. canadensis will begin laying eggs in the same swale.

By mid-August S. hineana adults were still seen at The Ridges Sanctuary, but their numbers were rapidly diminishing and the ones still flying often showed signs of age, such as wings with pieces missing and females with gray abdomens. And many of them didn't display the quick flight and aerobatic moves characteristic of those seen in mid-July. Their brief life in the sun was coming to an end.

Field Notes For End Of August

The last S. hineana at The Ridges Sanctuary was seen on August 29th. On this date a dead female and a nearly dead male were found along Ridges Road. The male showed no damage, but couldn't move its wings rapidly enough to fly. It may have been an old male that bounced off a passing car.  S. walshii and S. williamsoni were abundant near the end of August, and both species were busy laying eggs and patrolling swales. Some were seen even in early September, when the Canada Darner (Aeshna canadensis) becomes the predominant large dragonfly at the Sanctuary.

To summarize, S. hineana was seen at The Ridges Sanctuary from June 8th through August 29th. It appeared to be a good season for the species, for individuals were present in abundance. One thing that stands out about the summer is the number of roadkill specimens seen along the mile or so of Highway 57 north of Baileys Harbor. A reasonable estimate of the loss of this endangered species along this stretch of roadway would be in the thousands. With a speed limit of 55 mph, and with most vehicles moving around 60 mph, many dragonflies end up as roadkill. And it's unlikely the State DOT would allow "Reduce Speed... Dragonfly Crossing" signs.   

Field Notes For 2002

 Another good summer for dragonflies, with S. hineana seen in abundance. I also noted more S. williamsoni than in the past, and in August S. walshii were quite abundant. The intense thoracic stripes of juvenile S. hineana continue to amaze us, with the rich yellow stripes becoming cream-colored and then deep golden as the dragonfly ages. In old individuals the stripes become reduced in size as more and more dark pigment is deposited.

It's worth noting that during the spring and summer of 2002 literally thousands of the Wandering Glider, Pantala flavescens, were seen. In the spring they swarmed over farm fields and meadows, later becoming more dispersed. One wonders why so many chose to spend so much time in Door County. Also, S. hineana were often spotted in Ephraim, where I live, and on numerous occasions they cruised our front yard and nearby meadow. No doubt about it, Door County is a mecca for dragonflies, and dragonfly watchers.   

Field Notes For 2003

Winter of 2002-03 was a dry one, and with minimal snow cover the frost line was unusually deep. Lots of private septic systems froze up, and a local plumber told me that in northern Door County the frost line was as deep as 9 feet in some places. I suspect soil and water froze pretty solid (and deep)  in wetland areas, and it's likely that this summer's crop of  some species of dragonflies was reduced due to the loss of pre-emergent larvae to freezing temperatures. I have no hard evidence for this theory, but the fact remains that, compared to last year, there were fewer dragonflies at The Ridges Sanctuary. Road kill of S. hineana along Highway 57 south of Baileys Harbor was way down compared to last summer. Last summer I would find up to a dozen or so roadkilled emeralds in one day on the drive to and from the Sanctuary... this year I found only a few. And I saw no large feeding swarms of emeralds as in the past. Another possibility, of course, is that 3-4 years ago, for whatever reason, not as many eggs were laid, accounting for fewer emerging larvae in 2003.

My impression was that the number of Ladona julia was lower than last year, along with Aeshna canadensis and Meadowhawks. Twelve-Spotted Skimmers and Widow Skimmers were fairly abundant. This summer, especially along the Mink River, I saw more Common Whitetails (Plathemisl lydia) than in the past, but this probably doesn't mean much.

I saw my first Hine's Emerald (a female) around June 12, and my last one in mid-September. While not as abundant as last year, during their "season" one could usually see a few while walking the trails at The Ridges Sanctuary. On August 25, 2003, a pair of S. hineana was seen flying around our front yard in Ephraim (confirmed by netting and releasing).

On July 12, 2003, I joined members of the Wisconsin Entomological Society on a field trip to the Mud Lake Wildlife Area in the Town of Liberty Grove. It was warm and sunny, and we netted, examined, and released several Hine's Emerald dragonflies (I have a FWS permit to do so). They were foraging low over a large meadow area capturing and eating whatever they could. We probably saw five or six in action. 

Field Notes for the Summer of 2004

     Overall, dragonflies were late to emerge in the spring. Also, field studies suggested that many of the more common dragonflies were not as abundant as in previous years. Most of these studies were done at The Ridges Sanctuary and the nearby Mud Lake Natural Area. One of the earliest dragonflies to be seen at the Ridges is the Chalk-Fronted Corporal (Ladona julia). Usually seen in mid-May, my first one was seen on June 8. During past years, this dragonfly was extremely common in the spring, but in 2004 they were remarkably less abundant than in previous seasons.

      Sightings of the Hine's Emerald Dragonfly (Somatochlora hineana) were greatly diminished compared to past summers. Usually they appear around mid-June, but it wasn't until June 29th that I saw my first specimen. On that same day, I also saw a Brush-Tipped Emerald (S. walshii). Based on my observations in 2004, the summer was not a season of abundance for studying and photographing Emerald dragonflies.

     Although populations of most common dragonflies appeared to be lower in 2004 than in the previous 3-4 years, some species were seen in considerable number. Green Darners (Anax junius) arrived in apparent usual numbers, and Skimmers were abundant, especially Twelve-Spotted Skimmers (Libellula pulchella) and the Dot-Tailed Whiteface (Leucorrhinia intacta). In contrast to last year, Wandering Gliders (Pantala flavescens) were not often seen. The Canada Darner (Aeshna canadensis), a prominent late summer dragonfly at the Ridges, was seen regularly, but they didn't seem to be as abundant as in past years. The Meadowhawk (Sympetrum) population in 2004 was disappointingly low in number.

     Why so few dragonflies in 2004? Winter was relatively mild. Spring was cold, wet, and late coming, which may have affected dragonfly emergence. But the more likely factors were periods of minor drought that occurred during previous summers, especially during egg-laying activities. There is no evidence to date that the bodies of water in which egg-laying and larval life occur has been compromised. Although portions of The Ridges Sanctuary were treated with glyphosate to kill Phragmites (Common Reed), there is no evidence that the herbicide has impacted the dragonfly populations in the area.

                                                      Field Notes from the Summer of 2007

In 2006 I switched from the Nikon digital camera system to the Canon 20D and 5D and associated lenses. Although the Nikon cameras are very well made and take great photos, I prefer the "in camera" processing software of the Canon. Canon photos are well exposed, sharp, and the colors are true to life. They often require no tweaking whatsoever when downloaded, except for minor tweaking with unsharp mask. I think Nikon lens bodies are a little better built mechanically than Canon bodies, but both manufacturers produce state-of-the art optics. 

The first Hine's Emerald Dragonfly (HED) was seen on June 6. The last time I saw HEDs was August 2, one male and one female (probably egg-laying), although I have no doubt that there were some HEDs around throughout much of August. Their numbers become progressively reduced, however, reducing changes of seeing them close enough to identify with certainty. This summer I identified with assurance a total of 35 females and 20 males, and high quality photos were obtained of 12 perched specimens and several in flight. Based on my 26 field trips during the "HED Season," I noted the following.
        1. Females apparently emerge earlier than males and begin foraging away from the area from which they emerged. The first copulating pair of HEDs was seen on June 25th.
        2. The greatest numbers of HEDs at the Ridges were seen from June 19 to around July 16.
        3. In past seasons, I have on several occasions seen feeding swarms of HEDs. This season I saw none. The most individuals I would see in a given area was two to four. One summer I saw over 50 HEDs in a swarm.
        4. The lack of rainfall in recent years could be considered a factor in determining the size of HED populations. However, a look at total rainfall on Door County from 1975 to 2004 indicates tha, year-to-year, total annual rainfall didn't vary that much. However, rainfall in Northern Door County was very spotty this summer, and in the Baileys Harbor, Ephraim, Sister Bay area we had over a month and a half of very little rainfall. In fact, by late August swales at the Ridges Sanctuary were dry.
        5. This summer, for the first time, I saw a female HED attack another and knock her to the ground. I thought she was dead, but when I reached down to pick her up, she came to life and flew away.
        6. The two major thoracic stripes of HEDs have been described as bright yellow or cream colored. In my experience, while the stripes are bright yellow in young individuals, the anterior thoracic stripe often turns almost white in an older HED.
        7. There is a two-mile stretch of Highway 57north of Baileys Harbor that bisects a wetland. In 1999, in two trips over and back from Ephraim to Baileys Harbor, I counted 12 HEDs killed by automobiles. This year I found one road-kill specimen.
        8. The lack of rainfall over the past few years must have had an impact on the HED population, if for no other reason than leading to a substantial reduction in prey populations. This summer there were fewer mosquitoes and deer flies than ever before in my experience. There are many unanswered questions about the survivability of larvae of various dragonfly species under drought conditions. Perhaps some dragonfly larvae are more sensitive to drought than others. In addition to the HED population being smaller in 2007, the Chalk-Fronted Corporal and Meadowhawk populations were down in the Ridges area. However, this was a banner year for Common Green Darners, Twelve-Spotted Skimmers, and Calico Pennants.
        9. I doubt that fluctuations in the HED population can be attributed to loss of habitat in the area, for the land in the vicinity of the Ridges, and nearby Mud Lake and Pickeral Pond are protected areas. It should be noted that by the end of summer, Ridges swales, Mud Lake, and Pickeral Pond were dry. 
        10. While there is still a sizeable breeding population of HEDs in Door County, the population has decreased in size over the past seven years. A wet summer or two may help answer the question as to whether the decrease in population is due to rainfall in the Ridges, Mud Lake, and Pickeral Pond wetland complexes.
        PHOTOS -- Figure 1 is a close-up of a young HED female showing bright yellow thoracic stripes and a copper-colored eye that will acquire its characteristic emerald color with age. All photos obtained with a hand-held Canon 5D or 20D digital camera, usually with a 70-300 mm image-stabilized lens. Figure 2 is a photo of a female HED captured and photographed in my front yard in Ephraim. When released, the female continue to forage. Figure 3 is my best photo thus far showing an HED in flight. This one shows the characteristic shape of the HED male, and the clasper is clearly visible.
                                     

                                      Fig. 1 -- Close-up of young HED female showing bright yellow thoracic stripes. 

                    Fig. 2 -- A lateral view of a mature female foraging over the front yard of a house in Ephraim, WI.

                                 Fig. 3 -- Profile view of a male HED in flight, with legs folded under the thorax.

 
                                                        Field Notes from the Summer of 2008

    On sunny days between June 1, 2008, to August 18, 2008, twenty-two field trips were made to Ridges Sanctuary in Baileys Harbor, WI..  Hikes were usually in the morning for 1-2 hours along selected trails that accessed areas where numerous dragonflies were seen in the past. I began seeing a few Hine's Emerald Dragonflies (HED) around mid-June. During my hikes I didn't see as many HEDs as in the past, probably because it was a cool summer with the temperature rarely getting above 75 degrees F during my hikes. Also, populations of both deerflies and mosquitoes were down compared with previous years.
    After mid-June, I would usually see one or two HEDs on my hikes. On June 30 I saw four HEDs (temp. 75 degrees), again on July 13 I saw four, on July 25 I saw about 15, and after that date I would see one to four specimens. On August 7, I saw four HEDs, and on August 18 I didn't see a single one. In general, females appear early in the season, then later males will be seen along the trails as mating behavior begins. A total of 61 HEDs were seen this summer, 21 confirmed females and 12 confirmed males. Another 28 were seen where the gender was equivocal.
    Except for the early arriving Common Green Darners, not many "larger" dragonflies were seen at the Ridges this summer compared to previous summers. Late in the season, even Canada Darners were not abundant. The populations of Chalk-Fronted Corporals and Meadowhawks were down compared to previous years, although I saw more Four-Spotted Skimmers at the Ridges than ever before. Road kill of HEDs along the highway 57 corridor that passes through wetlands north of Baileys Harbor was very low. Droughts during the past three summers may have had quite a bit to do with diminished populations of certain kinds of dragonflies, including HEDs, but drought conditions did not prevail this summer.
    Numerous high quality photos of HEDs and other dragonflies were obtained this season, all of which were taken of live specimens perched in their natural habitat. In a number of instances, a perched HED would allow me to take as many photos as I wished, and I would depart the scene without disturbing the insect. I used Canon 20D and 5D cameras, and a favorite lens was a Canon 180 mm Macro EF lens (L type) with an EF 1.4 extender (= about 250 mm). 

Other Dragonflies

Twelve-Spotted Skimmer, Libellula pulchella

Over a period of three years, about 30 species of dragonflies have been seen at The Ridges Sanctuary. As the season progresses, different species appear, remain abundant for a period as they complete their cycle of feeding, copulation, egg-laying, and death. Among the first to appear (late May) are the Chalk-Fronted Corporals and Common Green Darners (Anax junius), then one begins to see members of the Skimmer group and a few Emeralds. July and early August are the best times to see the Emeralds, and by mid-summer Meadowhawks are present in great numbers. In mid to late-summer, Darners are commonly seen, and by August the Canada Darners are becoming the predominate large dragonfly at The Ridges Sanctuary. Meadowhawks continue to be the predominate small dragonfly along the trails, and they persist until well into September. Shown below are two of several species of Aeshna seen at The Ridges Sanctuary.

At the left is a male A tuberculifera, the Black-Tipped Darner. This species was first reported at the Sanctuary in 1998 (it appears not to be present in great numbers). At the right is A. canadensis, the Canada Darner, a predominate late summer resident of the Sanctuary. This is a male. Other Darners seen in the area are Anax junius (Common Green Darner), Aeshna umbrosa (Shadow Darner), and Aeshna constricta (the beautiful Lance-Tipped Darner).

 

END

Shown below is a favorite egg-laying site for dragonflies at The Ridges Sanctuary

 

Listed Below Are Selected Sites And Sources That Pertain To The Hine's Emerald Dragonfly And Dragonflies In General

<http://www.museum.state.il.us> -- Go to menus and select Programs -- Entomology Research -- Hine's Emerald Dragonfly

<http://www.dragonflies.org> -- Highly detailed scanned images of dragonflies

<http://www.capecod.net/~bnikula/capecodlist.htm> -- Lots of information and photos

<npwrc.usgs.gov/resource/2000/dfly/dflyusa.htm> -- Distribution maps, photos, checklists, links, and many other features

<http://ridgesanctuary.org> -- Introduction to The Ridges Sanctuary

<http://www.hinesdragonfly.org> -- Introduction to S. hineana

Legler, Karl and Dorothy, and Dave Westover, 1998. "Common Dragonflies of Wisconsin" (contact: Karl Legler, 429 Franklin St., Sauk City, WI 53583).

Dunkle, Sidney W., 2000. "Dragonflies Through Binoculars," Oxford University Press, 266 pp.

Miller, Peter L., 1995. "Dragonflies," Richmond Publishing Company, P.O. Box 963, Slough, SL2 3RS, Great Britain, 118 pp.

Needham, James G., Minter J. Westfall, Jr., and Michael L. May, 2000. "Dragonflies of North America," (revised edition), Scientific Publishers, Gainesville, FL, 940 pp.

 

Copyright 2001 by Paul Burton/The Ridges Sanctuary -- All Rights Reserved

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