Tuesday, May 25, 2010

Twin-spotted Spiketail

During my recent foray into the north woods of Michigan, we visited an interesting site loosely known as the "Underground River". That's it, above, when not under the ground. This is karst country, and the underlying limestone is prone to patchy erosion. Sinkholes are common, and in places this stream disappears into the ground only to resurface elsewhere. There are points when you can hear its rushing waters in the subterranean depths through fissures in the ground.

Pretty cool stuff, and breathtaking scenery. We had a Winter Wren here, singing its impossibly complex symphony of trills, and many other interesting birds. Gay-wings, Bunchberry, Rose Twisted-stalk, and Striped Maple added botanical allure.

But it was a dragonfly that was my personal highlight at this spot.

Sharp-eyed Nina spotted this freshly emerged dragon on a young sapling, some 30 feet from the river. It is a Twin-spotted Spiketail, Cordulegaster maculata, and it still clings to the exuvia from which it emerged. It had lived a long time as a nymph - maybe a few years - in the swift stream, capturing tiny macroinvertebrates and whatever else it could grab.

The night previous to our visit, the dragonfly nymph responded to some internal stimulus, crawled from the stream and through the woods, and lodged on this plant. In a miracle of transformation, it burst from the confines of the exuvia, and slowly morphed into the beautiful spiketail that we see here.

Spiketails inhabit fast-flowing streams with ample forest cover along the banks. As this one matures, its eyes will become a brilliant emerald green, and it is quite cool to encounter an adult coursing low over the creek like a mini B-52 bomber. When they fly through a sunny opening, those eyes gleam like neon glow lights, visible from quite some distance.


1 comment:

OpposableChums said...

Amazing catch, amazing pix. Thanks for posting!