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.

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