Monday, August 09, 2010

Clamp-tipped Emerald spotted in Manistee Co.

Today, I received an e-mail from David Dister:

Dear Mark:

Today while checking a wetland area along the Little Manistee River (where I had discovered a massasuaga rattlesnake two summers ago), I noticed a quite distinctive dragonfly I was not familiar with. I managed to get a few marginal, though diagnostic, photos, and upon returning to my car and references, it appears to be Somatochlora tenebrosa. I have attached a few photos for your reference. The state mapping for this species on your website has Manistee County darkened, but the list of vouchers indicates only Benzie County records in the northwest LP.

With such a limited range, I was a bit surprised that this species did not have a Special Concern status in Michigan. In any event, the basic data on the location is as follows:

  • Manistee Co., Stronach Township, Manistee National Forest; T21N/ R 16W/Section 23
  • Feature: Flying and perching in scrub-shrub/emergent marsh wetlands on north side of Little Manistee River
  • August 8, 2010 Dave Dister
  • Sex: Male
  • Notes: Photo voucher only

While I am not surprised that David found S. tenebrosa in Manistee Co. (Carl Freeman had many collections of it in nearby Benzie Co.), the indication is that he found it in a fen, as that's also a place to find the Massasauga rattlers! Maybe we should be looking at known Massasauga sites and see if Somatochlora tenebrosa is also there. Sometimes the answer stares right at us and we don't see it for a long time.

Hopefully, we will get a specimen vouchered for the site, and I am glad that David was alert to realizing he was seeing an uncommonly-collected species in MI.

Sunday, August 08, 2010

Sharon Hills Preserve

Continuing my theme on Washtenaw County preserves, today's post is about yesterday's trip to Sharon Hills Preserve. Located off Sharon Hollow Road, this 69-acre preserve is mostly old fields with some wooded areas. Although there are significant wetlands to the south, I don't believe they are part of the parcel. As the name implies, the preserve is hilly - some nice glacial mounds with predominantly sandy soil.

Adrienne and I arrived in late morning, and the first thing we encountered were several darners and gliders feeding over a grassy depression. I spotted Tramea lacerata, Pantala flavescens, Anax junius, and an Aeshna that I would eventually catch and identify as Aeshna tuberculifera. While these upland areas may not be Odonata breeding habitat, they are essential feeding habitats, and based upon the number of darners we saw, I'd say there was a lot of feeding going on. In addition, I saw the largest concentration of Sympetrum semicinctum that I have ever seen. They were very, very, common at the preserve. We also saw a few Libellula pulchella, Libellula luctuosa, and a Pachydiplax longipennis, which is getting late in the season for that species.

Sympetrum semicinctum

The A. tuberculifera were numerous -- I counted many dozens, and the 5 that I captured were all males, a couple were saved for vouchers. Based upon what I saw, it was the only Aeshna species there that day. Typically, they were either flying less than 6 feet above the ground, and often into the grasses and open vegetation, making it difficult to track them. I saw many settle down, perched from a twig in the shade. The Green darners were mostly swooping around over 6 feet above the ground, or hanging from a bush.

Aeshna tuberculifera

We saw three treefrogs, and they are always a delightful find.

Vegetation-wise, we saw lots of invasive herbaceous plants - hedge parsely, some Euphorbia, some spotted knapweed, the ubiquitous Queen Anne's Lace, and soapwort. We did not see any of the teasel that has become so much of a problem. The dry hills there could be reseeded for more prairie-type species that would give the site a more oak-savanna type of habitat.

So, while we didn't find any nice wetland on the preserve, we did see lots of butterflies and other insects, and diversity is the key here.

Sunday, August 01, 2010

NE Washtenaw Preserves

Anax junius at LeFurge Preserve

Today I decided to pay a visit to two preserves in the NE part of Washtenaw County - LeFurge Preserve and Kosch-Headwaters Preserve. The Washtenaw County Natural Areas Preservation Program, NAPP, has been active in acquiring parcels that help preserve and enhance the watersheds and also feature an array of habitats. Another organization, the Southeast Michigan Land Conservancy, has been active for well over a decade, acquiring properties and consolidating holdings on the eastern edge of the county, and the star has been the LeFurge Preserve - 325 acres of wetlands, old fields, and some woods. I visited the LeFurge wetland back in 1999, when it was first being developed into a quality wetland. Today’s visit was the first since then, and it was gratifying to see how much the preserve has been enhanced with natural plantings, as well as the nice parking area.

The wetland there is predominated by a cattail marsh with deeper areas featuring a lot of water lilies and other emergent aquatic vegetation. In 1999, Anax junius was common there, and today, it was really abundant. I was amazed at how many I saw flying there. They truly seemed to own the airspace. I also saw a few Tramea lacerata, many Sympetrum obtrusum, Pachydiplax longipennis, and a few Ischnura verticalis. Obviously, a sample early in the season would be good. I’ll try doing that next year.

My next stop was the Kosch-Headwaters Preserve, a bit farther N on Prospect Rd. A relatively new preserve, it was acquired in 2006 by NAPP. This preserve is 160 acres in size, and is actually in the River Rouge Watershed, not the Huron River. Much of the area is covered with old fields, some woods, good brushy areas, and a wooded pond. Some of the preserve is also cultivated farmland. I didn’t really know what to expect here, but the terrain is somewhat hilly, and the meadows supported a LOT of butterflies. Odonata-wise, it’s not going to be too impressive, but I did find a lot of Lance-tipped darners, Aeshna constricta, which I assume are coming from the wooded pond or some nearby open ponds. I saw Libellula pulchella, Libellula luctuosa, Plathemis lydia, Tramea lacerata, and many Sympetrum at the field edges. I did not see a single Anax junius there, even though the preserve was less than a mile from Lefurge! This shows how good it is to have a diverse habitat -- and those wooded ponds are very important. One of the original points about the Kosch Headwaters Preserve was the presence of Blue Ash. I wonder if the Emerald Ash Borer has taken that out, too.

wooded pond -- there are several whitetail fawns there, but you can't see them!

Aeshna constricta.

I hope to visit as many of the Washtenaw County Preserves as possible in the remaining two months of the Odonata season, and possibly scout out others for next year.