29 August 2010

RFI: Russet-tipped Clubtail habitat requirements

Of the many new county records we have obtained, one of our favorites is the Russet-tipped Clubtail, Stylurus plagiatus. (When we found it in 2001, it was actually a first state record, but we've only just determined that what everyone thought was the first state record, from Alpena Co., was an error.) Darrin even adopted it as his nom de plume/avatar for this blog.

The areas where we have found adult S. plagiatus appear to have specific characteristics. We are interested in gathering more data about these characteristics. Ergo, this request for information on locations where verified (photograph or voucher) adult S. plagiatus have been found.

Where: We are concentrating on populations in MN, IA, MO and all states EAST of the Mississippi and north of (and including) TN and NC -- all the states shaded in yellow below; eastern Canadian provinces, too, although they are very rare in Canada.

What: We would like precise geo-coordinates of locations where you have seen adult Russet-tipped Clubtails, S. plagiatus.
  • These should be verifiable sightings, documented by a photograph or voucher. We don't need a copy of the photo, but would like a link if it's online. We might ask to see an image, but we'll write to you if need be. If you have taken a voucher, let us know where it is archived and a specimen number, if applicable.
  • We'd like a location within 20 meters if possible -- this precision usually easy to get on Google Earth by creating a placemark and then copying the coordinates in the Edit Placemark box. We'd prefer digital coordinates (e.g., 42.394098, -83.736619). Google Earth will display this if you choose "Decimal degrees" in the "Show lat/long" section of Google Earth Options. But we can convert if necessary.
When: Anytime within the last 10 years.

How: Fill out and submit our nifty online form at Wufoo. You can fill out one form per area, even if you've had multiple sightings over multiple years. Just let us know that in the Notes section of the form. In fact, since we're limited in the number of fields on the form, please provide as much detail as you like in the Notes section!

Why: We'd like to verify some of our suspicions regarding the apparently very specific habitat configurations and requirements of adult Russet-tipped Clubtails. In order not to bias any data submissions, we won't reveal our hunches here right now. If we are able to obtain a good sample, we'll compile our data and see what shakes out.

Our intention is to share this data, via publication and this blog, in order to help preserve and manage for populations. This is driven by our concern that this species may already have been extirpated from the spots where we originally found them. The reduction (or loss) of this population has prompted us to do some work on the requirements of this S. plagiatus, as it is a species of special concern in Michigan.

Here at the northern portion of the range of Russet-tipped Clubtails, peak flight time is mid- to late August, but they will be on the wing into September. So if you don't have any old records to provide us, now is a great time to get out and look for this handsome dragonfly and let us know where you found it!

Adding to the Lenawee list

August 28th, 2010, was a nice day to explore a couple Lenawee County, Michigan, locations for odes.

Tecumseh has a variety of great locations in/near the Raisin River.

My first targets were the gliders (Pantala sp.) so I checked the open field area that is scheduled to be a housing subdivision along the west side of Red Mill Pond. Fortunately for the flora and fauna, the subdivision construction has been stalled (due to the poor economic times?). The field contained a good variety of native plants. Monarchs were on the move and I was able to tag several while searching for the dragonflies. Common Green Darners (Anax junius) and Black Saddlebags (Tramea lacerata) were in the air overhead.

I found a female Band-winged Meadowhawk (Sympetrum semicinctum) perched on a small shrub:

Eventually I found a couple Wandering Gliders (Pantala flavescens). Here is a female and the first for the database:

I decided to check another location a bit west before returning to another Tecumseh location. Bicentennial Woods is a county park along Tipton Highway with old growth woods and a small waterway named Black Creek running through it.

In past years, we've observed Fawn Darners (Boyeria vinosa) along the stream and I thought it would be good to check again. Upon arriving at the creek's bank, a Mocha Emerald (Somatochlora linearis) was flushed from the nearby vegetation. A few more individuals were found in/near the sunlit portions of the creek. Here is a male and the first for the database:

One female Fawn Darner (Boyeria vinosa) was observed ovipositing along the creek.

Male Lance-tipped Darners (Aeshna constricta) were patrolling the edge of the woods:

Returning to Tecumseh, I visited Indian Crossing Trails Park along the Raisin River below Standish Pond. This area typically provides views of many interesting odes:

- Fawn Darner (B. vinosa) = A female was observed ovipositing on downed trees along the river.

- Black-shouldered Spinyleg (Dromogomphus spinosus) = One male perched on the exposed rocks below Standish Dam while another perched at the boat launch above the dam. One female perched in the vegetation below Standish Dam and another was found downstream on the riverside trail:

- Arrow Clubtail (Stylurus spiniceps) = A few males were observed patrolling the river downstream from Standish Dam:

- Illinois (or Swift) River Cruiser (Macromia illinoiensis) = A couple males patrolled the river below the dam, but I couldn't capture either of them for a county first.

I'll need to return in the future to search for more gomphids along this area of the Raisin River.

... Lenawee County has many more species to find.

17 August 2010

The mystery of meadowhawks

A putative Ruby Meadowhawk.

[Updated July 2019 to include additional data and references]

In our post Identifying Odonata from photographs, we talked about one of the more vexing field IDs around: the red meadowhawks in the genus Sympetrum. Since meadowhawks are a signature species of late summer, I thought they would be a good start to what we hope is a series on difficult genera.

Here is the bottom line: Over most of eastern North America, the most common meadowhawk species (Ruby, White-faced, Cherry-faced, and Jane's) should not or cannot be identified to species from a photograph -- especially when immature. Often, they cannot even be identified to species in the hand because the structural characteristics of their genitalia are intermediate due to hybridization. In fact, DNA analysis has shown that some of these "species" may not be full species, or may still be undergoing speciation. 

Harsh and disappointing news to those coming from the world of birding where most species can be identified by sight or sound and added to a list, or those unable to or opposed to netting or collecting insects and investing the effort to carefully examine and key them out, or submit them to those who will.  Of course, your list is your own, and if you would like to call reddish-faced meadowhawks Ruby or Cherry-faced, that's all good. But we think it is a disservice to our understanding of the distribution, abundance, and species limits of Sympetrums for folks to so confidently and publicly (mis)identify meadowhawks. What follows is a short explanation of the difficulties of identification of some of the common eastern species, and some resources for additional reading.

We'll focus on the species that most commonly cause confusion in eastern North America (although some also cause problems in the west, and there are other species that also sow confusion!) :
  • Sympetrum rubicundulum (Ruby, hereafter RUME)
  • S. internum (Cherry-faced, CFME)
  • S. obtrusum (White-faced, WFME)
  • S. janae (Jane's Meadowhawk, JAME)

Generally, we've been told that the field marks to look for include the pattern of black on the abdomen, color of the face, and color of the legs. There is geographic variation for some species in some characters. When immature, meadowhawks are largely yellowish-orange, with facial colors in particular not fully developed or helpful.

In the east, the face of CFME is brownish and this species cannot be separated from RUME (face yellowish to brownish) in the field. In the hand, examining the hamules under good magnification may help. However, there are intermediate forms (with intermediate-looking hamules) that cannot be identified to species. Some consider them hybrids, a subspecies of CFME, or (at least along the Atlantic seaboard) a separate species, JAME. Genetic work on these three species is inconclusive.

Mature WFME have very white faces, which should be helpful. Until maturity, though, eastern forms cannot be distinguished from CFME in the field. Even in the hand, immature female CFME and WFME cannot be separated in the east, as their subgenital plates are essentially identical (in the west, the subgenital plate of CFME is quite different from eastern forms). WFME also hybridize, or have intermediate forms, with both RUME and CFME.

A putative White-faced Meadowhawk.

Here is what Ken Tennessen had to say about the genus in his recent book: "...the status of several taxa based on adults remains controversial, including morphological evidence of possible intergradation between adults of S. internum, S. obtrusum, and S. rubicundulum... Pilgrim and von Dohlen (2007) were unable to find consistent species-level differences between adults of S. janeae, S. internum, and S. rubicundulum based on either morphological or DNA data; their analysis indicated that there is gene flow between [these species] or that these forms are the result of a recent radiation."

Smith-Patten and Patten (2013) have settled on a great name for Ruby/White-faced/Cherry-faced -ish meadowhawks: RuWhiChes (rue-WEE-cheez).

There is a more distinctive meadowhawk, Sympetrum semicinctum, the Band-winged Meadowhawk (BWME), found across most of the central and northern U.S. It varies geographically, causing problems in some areas. In the east, identification is usually pretty straightforward as the wings are amber-colored to the nodus. However, some RUME west of Ohio may have amber wing bases, sometimes as extensive as BWME. In the Great Plains and to the west, Band-winged Meadowhawk wings may be colored, clear, or diffusely colored. In the center of the country, clear-winged forms are probably not separable from CFME and RUME. The western forms are often considered their own species, S. occidentatale, but genetic work indicates that S. occidentatale is not a valid species.

An eastern Band-winged Meadowhawk.
In the Great Plains and to the west, wings may be colored, clear, or diffusely colored. In the center of the country, clear-winged forms are probably not separable from CFME and RUME. The western forms are often considered their own species, S. occidentatale, but genetic work indicates that S. occidentatale is not a valid species.

Likewise, in Europe, there are no good morphological characteristics to distinguish Common Darter (S. striolatum) and Highland Darter (S. nigrescens), and genetic work was also unhelpful.

Beware of the little red odes of summer.

Additional reading:

Caitling, P. M. 2007. Variation of hind-wing colour and length in Sympetrum internum (Odonata: Libellulidae) from the Canadian prairie provinces Canadian Entomologist 139(6):872-880. (Abstract)

Canning, R. A., and R. W. Garrison. 1991. Sympetrum signiferum, a new species of dragonfly (Odonata: Libellulidae) from western Mexico and Arizona. Annals Ent. Soc. America. 84:474-479.

Carle, F.L. 1993. Sympetrum janae spec. nov. from eastern North America, with a key to nearctic Sympeturm (Anisoptera: Libellulidae). Odonatalogica 22(1):1-16.

Donnelly, T.W. 1991. Current problems in Sympetrum and Libellula (a.k.a. Plathemis). Argia 3(4): 8-12.

Donnelly, T.W. 2013. The meadowhawks (Sympetrum): America's oldest problem odes; or, the romance of hybridization. Argia 25(4): 23-25.

Parkes, K. A., W. Amos, N. W. Moore, J. I. Hoffman, and J. Moore. 2009. Population structure and speciation in the dragonfly Sympetrum striolatum/nigrescens (Odonata: Libellulidae): An analysis using AFLP markers. European Journal of Entomology 106:179-184. (Abstract)

Pilgrim, E. M., and C. D. Von Dohlen. 2007. Molecular and morphological study of species-level questions within the dragonfly genus Sympetrum (Odonata: Libellulidae). Annals of the Entomological Society of America 100:688-702.

Smith-Patten, B., and M.A. Patten. 2013. First record of the White-faced Meadowhawk (Sympetrum obtrusum) for Oklahoma, and a review of the status of the Cherry-faced Meadowhawk (S. internum) in the state. Argia 25(2)12-13.

This has nothing to do with taxonomy, hybridization, or identification, but I came across it in my research and had to throw it in because I liked the title:

Horvath, G., P. Malik, G. Kriska, and H. Wildermuth. 2007. Ecological traps for dragonflies in a cemetery: the attraction of Sympetrum species (Odonata: Libellulidae) by horizontally polarizing black gravestones. Freshwater Biology 52: 1700-1709.

11 August 2010

Branch-ing Out

I joined Nannothemis for a trip west. She had a MiBCI meeting south of Coldwater, MI and I decided to skip the meeting and spend time along the Coldwater River in Branch County, Michigan on August 10th.

This county hasn't been sufficiently surveyed for odes through the years with only 27 species tallied and all records before 1964. Thus, it was time to add species and make some updates.

1. My first stop around noon was a great location along the Coldwater River, Riverbend County Park. This clear water river appeared to have much potential with a nice flow and a good mix of substrate (gravel, stones, sand, silty areas at the riverbends).

Given the visible attractiveness, I wonder if agricultural runoff affects the water quality and species richness. The southern border of the park is surrounded by corn fields and posted with signs such as this:

Initially, much of the river access was shaded and only a couple damselflies were out and about. Most numerous were Ebony Jewelwings (Calopteryx maculata), followed by Blue-ringed Dancers (Argia sedula). Here is a male dancer:

Walking the main loop trail didn't turn up any other species, which was curious given the nice-looking habitat.

Heading downstream along a riverside trail, I flushed a darner which perched on the branch of a small tree. It ended up being a male Fawn Darner (Boyeria vinosa):

While poking around a bit more, a male Fragile Forktail (Ischnura posita) and Blue-fronted Dancer (Argia apicalis) were found in the riverside vegetation.

Near the west end of the park, I scanned the opposite, sunlit bank and along came a Dragonhunter (Hagenius brevistylus) with its distinctive J-shape of the abdomen. This was only the third time I've seen one in MI. I worked my way back to another small, sunny location hoping to find the big ode, but found another clubtail instead.

A female Black-shouldered Spinyleg (Dromogomphus spinosus) tapped the water a few times then perched on a leaf nearby:

Retracing the main loop, I had hoped that more sun would be on the riverbanks. No need. I happened upon a female Dragonhunter (H. brevistylus) perched in a small, sunny spot along the trail. I tried to approach for a photo, but she kept flushing and flying to the next sunlit vegetation along the trail. Then around the next bend in the trail, a male Fawn Darner (B. vinosa) flushed and perched on a branch. The next corner produced a coupled pair of the same species (digiscoped through my binoculars):

Surprisingly, I didn't see any river cruisers (Macromia sp.) or hanging clubtails (Stylurus sp.) in this great-looking habitat.

My second stop was the one-lane bridge over the Coldwater River along Stancer Road. A small dam lies under the bridge.

The wide, slow-flow area above the dam provided Violet Dancer (Argia fumpipennis violacea), Fragile Forktail (Ischnura posita), and Blue-fronted Dancer (Argia apicalis) such as this male:

As soon as I arrived on the gravel bar downstream, a Dragonhunter (H. brevistylus) landed at my feet. I snagged this male for a closer view of this large species:

Soon after a second male arrived at the gravel bar:

... and I even saw a third patrolling the river.

The third stop was at Hodunk. A dam downriver from Hodunk Road creates a wide spot in the river and provided many pond species.

Zygoptera included Skimming Bluet (Enallagma geminatum), Stream Bluet (Enallagma exsulans), and Swamp Spreadwing (Lestes vigilax) such as this male:

Anisoptera included Widow Skimmer (Libellula luctuosa), Slaty Skimmer (Libellula incesta), Eastern Pondhawk (Erythemis simplicicollis), Common Green Darner (Anax junius), Prince Baskettail (Epitheca princeps), Eastern Amberwing (Perithemis tenera), Black Saddlebags (Tramea lacerata), Halloween Pennant (Celithemis eponina). Posed is a Common Green Darner (A. junius) exuvia on a grape leaf:

4. & 5. Additional short stops included the Randall Lake Public Boat Launch and Coldwater's Rotary Park for additional pond species including Eastern Forktail (Ischnura verticalis), Blue Dashers (Pachydiplax longipennis), meadowhawks (Sympetrum sp.), and male American Rubyspots (Hetaerina americana):

My afternoon field time was up and I had to return for the MiBCI group dinner.

Nannothemis was envious of a couple of the species observed so we returned to the Coldwater River the following morning. We hoped for good photos due to her superior camera, but the weather did not cooperate. We arrived at the Stancer Road bridge area under cloudy skies and a breeze that kept leaves blowing around. However, there were two Dragonhunters (H. brevistylus) near the gravel bar. Alas, they didn't cooperate. When one did return a bee bumped it from its perch on the rocks and a photo wasn't possible. I did spy a River Cruiser (Macromia sp.) patrolling above the dam, but it didn't come close enough to provide an ID.

Our next try was Riverbend Park, then the storm front arrived and rained us out. We ended up driving home through rain for over 2.5 hours.

Overall, it was a successful, short visit. 13 species were added for the county bringing the total to 40. (only 3 of these are sight-only records) Of course, additional visits during other times of the season and to other habitats would greatly bolster this county's species total.

01 August 2010

Hotspot on the Huron

Nannothemis and I heard of a boggy area in Island Lake State Recreation Area in Livingston County, Michigan, so we decided to search for it on July 25th. We had hoped to obtain photos of the real Nannothemis bella and poked around various areas of the park without finding the exact location.

However, while searching we found a great location along the Huron River at the canoe campsite area. It is removed from the busy parking lots and roadways that were swarming with all the bicyclists. The only people at this location were the canoeists paddling down the Huron. As soon as we had arrived at the riverbank, we saw two Dragonhunters (Hagenius brevistylus) working the far bank and one perched on the branch of a downed tree. I thought this would be my chance to see this species in the hand for the first time in MI so I waded out. Unfortunately, the recent rains had increased the depth of the river and I couldn't cross without immersing myself so I waited at the nearshore. Even with the passing disruptions of the canoeists, the large dragonflies wouldn't cross to my side.

During my time in the water, additional dragonflies turned up that aren't found every day around here.

- A Black-shouldered Spinyleg (Dromogomphus spinosus) flew in and perched on a tree just upstream. There was no possibility to approach due to the water depth and the shoreline vegetation.

- Two or three Royal River Cruisers (Macromia taeniolata) flew up and down the waterway. One male came too close to me and became the first record for the county:

One has to love their eyes:

- Eventually a darner arrived and worked the middle of the river, occasionally scrapping with the river cruisers. The abdomen was noticeably stout and seemed a bit shorter than the typical Aeshnids. The eyes were bluish and the "nose" also projected out from the face provided features to ID this as a Cyrano Darner (Nasiaeschna pentacantha)! This is the latest date we have seen this species in SE MI.

- The most numerous species at this location was the Blue-ringed Dancer (Argia sedula). We know of only one location for them in our home county of Wayne, but I suspect these are more common in better quality water areas such as this.

We didn't find the boggy area, but we did find a great location for odes.
(Nannothemis did return a few days later and found the boggy area near an old sand/gravel area with a spring-fed lake.)