Last week I added the Common Sanddragon dragonfly (Progomphus obscurus) to the species list at Huntley Meadows Park, the marsh where I spend a lot of time walking and photographing. The park keeps a comprehensive list of species and it appears that this particular dragonfly had never before been observed and photographed within the park.
I came across this dragonfly, which I recognized as some kind of clubtail, when I was hiking through a back area of the park. I was struck by the way the dragonfly was patrolling a small sandy stretch of a creek and kept returning to perches on that little beach. I took quite a few photos of the dragonfly, though I really wasn’t sure of its identity.
The images would have remained unviewed on my computer for several days, but I mentioned my discovery to fellow blogger and photographer, Walter Sanford, who seemed to sense that I had captured something a bit out of the ordinary. He insisted that I send him a couple of images immediately, which I did. Walter tentatively identified the dragonfly as a Common Sanddragon and confirmed the identification with Kevin Munroe, who manages Huntley Meadows Park and is a dragonfly expert.
Kevin has a wonderful website, Dragonflies of Northern Virginia, that is full of fun and useful information about dragonflies in our area. In the section about Common Sanddragons, he notes, “Despite its name, this species is rare in Northern VA. In other parts of the country, where clean, sunny, shallow creeks with plenty of sandy/gravely banks are common, so too are Common Sanddragons. Our urban waterways are too influenced by stormwater, flowing fast and unchecked off impervious surfaces (roads, parking lots, roofs, etc.). This creates deeply incised, eroded banks and streambeds with excess silt, unstable flows.”
As a kind of experiment, I angled a couple of sticks in the sand to see if I could get one of them to perch on the stick. Although they kept returning primarily to the sand, a couple of times one perched on the stick and I got this shot.
You may have noticed the raised tail in several of the shots. In other dragonflies, the “obelisk” position is a method of thermoregulation, but I am not sure if this is the case here—it might be related to efforts to attract a mate.
© Michael Q. Powell. All rights reserved
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Mike Powell 