I am becoming convinced that dragonflies are rulebreakers. Yesterday I noted that dragonflies do not always follow the rules and can sometimes be found in habitats where they are not supposed to be. Apparently they also do not know how to follow a calendar and can sometimes be found earlier or later than the rules and records indicate they will be present.
This past Monday I was back at Occoquan Bay National Wildlife Refuge, searching again for the rare Fine-lined Emerald dragonflies that I had seen there previously. When I saw a dragonfly with bright green eyes perch in a distant tree, I naturally assumed that it was a Fine-lined Emerald. It is getting to be late in the dragonfly season, so many other species are no longer present. The dragonfly never got any closer, so I had to be content with my long-distance shots.
When I pulled up the images on my computer, something didn’t look quite right. The shape of the body seemed a little different from the Fine-lined Emeralds that I had seen previously and the tips of the abdomen (the “terminal appendages”) also looked different. I consulted with some dragonfly experts and they identified the dragonfly to me as a Mocha Emerald dragonfly (Somatochlora linearis). I have seen this species before, but in a totally different environment and much earlier in the year, so I had mentally removed it from consideration.
Now I don’t feel too bad about missing the identification, because the two species are part of the same genus Somatochlora, also known as Striped Emeralds. The website Dragonflies of Northern Virginia indicates that the flight records for the Mocha Emerald are from 16 June to 16 September—I guess that window can now be extended a little.
I am including two photos of the Mocha Emerald that may look almost identical, but were shot with two very different cameras. The settings for the cameras were almost the same with an aperture of f/7.1 and a shutter speed of around 1/400 of a second and both were handheld. The first shot was with my Canon 50D DSLR and Tamron 150-600mm lens. Taking into account the crop factor of the camera, the field of view was equivalent to 960mm. The second shot was with my Canon SX50 with a field of view that was equivalent to 1200mm.
The DSLR was a lot heavier and a lot more expensive, but produced a more out-of-focus background. The Canon SX50 was cheaper, lighter, and brought me in closer to the subject. It’s clear to me that equipment did not make a huge difference in this case and that there are advantages and disadvantages to each system. I am increasingly drawn to the idea of carrying both with me for the moment and continuing to experiment with them.
The other big lesson that I continue to learn is to expect the unexpected. As I am discovering, subjects may pop up in places and at times when you least expect them.
© Michael Q. Powell. All rights reserved.
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Mike Powell 