Monday, November 26, 2012

The Case Of The Constipated Darner

The story of the Constipated Darner is an interesting one for a number of reasons, not least of which is how it illustrates the deep connection I've developed over the years with the Happy-face Darner (Paddle-tailed Darner).  I first interacted with this dragonfly as a child, when I brought a live one into the house.  More recently, at Cranberry Lake, I discovered its delightful happy-face, and its method of cleaning by splash-dunking into the water and then spin-drying at 1,000 rpm in mid flight.  I've rescued a  number of them that got stuck when they splash-dunked, and have also gotten good at lifting them up from a perch onto my finger for a little visit.  I've even had a Happy-face come to my deck for a house call.  They've brought out the "dragonfly whisperer" within me.

This story begins at Cranberry Lake.  Betsy and I were observing male Happy-face Darners as they flew about the lake searching for mates and interacting with one another.  Suddenly, we saw one begin a series of splash-dunks.  We counted them out as they progressed:  "1, 2, 3, 4, 5, 6, 7, 8".  Wow, eight in a row.  That was a record!  Below is a table of the number of splash-dunks per event versus the number of events for the last two years – including this new observation.  We've seen a total of 265 splash-dunk events, with an average number of 2.31 splash-dunks/event.

Splash-Dunks per Event               Number of Events
1                                                        94
2                                                        65
3                                                        60
4                                                        28
5                                                        13
6                                                        4
7                                                        0
8                                                        1

After completing its 8 splash-dunks, and a nice spin-dry, the darner flew to a cedar tree near the shore to perch.  We could see it clearly, though it was fairly high up.  We noticed something attached to its abdomen, trailing off the back end.  Was something stuck to the darner?  Apparently so.  It was about the length and color of a pine needle.  Did this account for its record number of splash-dunks, as the darner attempted to dislodge whatever this was?  In fact, as we watched, it flexed its abdomen and tried to remove the material by rubbing it against a leaf, but was unsuccessful.

I reached up and grabbed the lowest branch of the cedar tree, and was able to pull down enough to bring the darner closer for better observation.  We saw that it was distressed over this attachment to its abdomen, and that flies were attracted to it.  We began to realize it might be a string of excrement still attached to the unfortunate creature.

At this point I realized that I could now reach up and grab the next higher cedar branch, and bring the darner even closer.  I did so, and got it close enough that I was able to reach up and lift it onto my finger.  Now we could examine it in detail.  Indeed, it had a long string of excrement attached to its abdomen that it was trying to remove.  I took hold of the far end of the string, which was dry and a light tan color, and pulled.  The string separated cleanly from the darner, and it seemed relieved.  I took a few pictures of it on my finger, and then placed it back on a cedar branch where it rested for several more minutes before flying off.

I wonder how the problem developed in the first place?  Or perhaps the better question is: Why doesn't this sort of thing happen more often, given that dragonflies have no fiber in their diet?  Whatever the case, I never imagined my connection with the Happy-face Darner would extend to a situation like this.  I was happy to help, though, and I hope it was able to continue its dragonfly pursuits in a more regular fashion.

Here are a couple photos from this adventure:

The darner perched in the cedar tree with the attachment to its abdomen.  Notice the fly, whose presence is not a coincident.

After pulling the cedar branch down I was able to reach the darner and lift it onto my finger.

So is this why he splash-dunked eight times in a row?  It seems quite likely.

I was able to pull off the attachment and make a clean break.

My friend the Happy-face Darner seemed pleased with the result.

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