What do you do to cope on a hot sunny day? Most of us stay indoors in an air-conditioned space, possibly with a cold beverage. Dragonflies do not have those options, so many of them assume a pose, often known as the obelisk posture, in an attempt to regulate their temperature by reducing exposure to the direct sunlight.
You may seen dragonflies in a handstand-like pose, looking like gymnasts in training—that is the obelisk posture. The dragonfly lifts its abdomen until its tip points to the sun, thereby minimizing the amount of surface area exposed to solar radiation. At noontime, the vertical position of the dragonfly’s body suggest an obelisk, which in my area immediately brings to mind the Washington Monument. According to Wikipedia, scientists have tested this phenomenon in a laboratory by heating Blue Dasher dragonflies with a lamp, which caused them to raise their abdomens and has been shown to be effective in stopping or slowly the rise in their body temperature.
While visiting Green Spring Gardens last week on a hot humid day, I observed obelisking behavior in a male Blue Dasher (Pachydiplax longipennis) and a male Eastern Amberwing (Perithemis tenera). I have always been intrigued by this pose and would love to try it out to see if it works for thermoregulation in humans too. Alas, I lack both the upper-body strength and the lower body flexibility to make a go of it, so I’ll continue to be merely a spectator of these beautiful little acrobats.
© Michael Q. Powell. All rights reserved.
Mike Powell 
Haha, I knew eventually you’d mention your own wishful pose-ability. 😄❤️ Fascinating info and images.
Thanks, Laura. I guess I am getting predictable. Although posing is something I would love to do, flying is at the top of my list. 🙂
😂❤️
Nice Mike! Now that would have been an interesting post to see!😊
Five judges give the first one 9.6 9.6. 9.5 9.7 & 9.6 – I think it gets the gold.
I’ve seen this, but didn’t know what was going on until recently. In fact, I think I learned about it from your blog.
If you leave your shovel lying flat on the ground in the sun the handle will get very hot. If you lean it against a fence so that the handle is vertical it won’t get hot. I guess this is the same principle. Fascinating to hear that nature knows about this technique as well 🙂
Wo. I never thought about a shovel like that, but it is undoubtedly true. It is amazing how well insects, birds, and animals understand our natural world and how that understanding is passed from generation to generation.
I love this idea obelisking… what genius the natural world. What a great capture in the photos. Thank you, Mike
Very interesting! I’m enjoying this Odonata Education! William
Thanks, William. I love passing on fun info that I have learned about the creatures that I photograph.
The Blue Dasher is so cool! Get it? He really knows how to do a great handstand. I can do a handstand but I go over pretty fast like a somersault. But when I do it against a wall I can stay up longer. Both photos are really awesome Dragonflies. Guess what? I know why the Dragonflies use this position when it is hot outside. All insects are ectotherms which means the temperature around them controls the temperature of their bodies. Squirrels and birds and me, we are endotherms. Gem and I learned that when we studied all about insects and animals last year. Thank you, Mr. Mike, and Bye!
I liked you little joke, Benjamin. A long time ago I used to be able to do a handstand against a wall for a really short period of time, but I think I would have to practice now to do one. It is wonderful that you know all about ectotherms and endotherms, what we used to call cold-blooded and warm-blooded. You know a lot about science, Benjamin, which I think is really cool.
They’re natural “posers” for your pics. Cool 😎. I wonder if they do duck-faces?
Duck-faces? Yikes. You have now planted in my brain the idea of dragonflies taking tiny selfies. 🙂
Tee hee. 😏 Unfortunately after years of being in schools my mind went there. LOL. Great pics!
thanks you for teaching me something. I’ve seen this posture on occasion. Now I know more about it.
You are welcome, Sherry. Some scientists think that with certain species there may be an element of males posturing to other males, but generally the obelisk behavior is believed to be associated with thermoregulation.
You don’t have to do a handstand or stand on your head when the sun is directly overhead to take advantage of this technique; all you have to do is stand up straight and wear a hat. The wider the brim, the more effective it is, hence the ultimate one, the sombrero.
Well, I do stand up pretty straight when I am out in the sun, though generally my hat of choice is a baseball-style cap rather than a sombrero. Somehow I think my subjects would laugh at me if I wore a sombrero–a few years ago I celebrated my birthday with some friends at a Mexican restaurant that brought out an enormous sombrero for me to wear while they serenaded me with “Happy Birthday”–I felt utterly ridiculous.
I wasn’t actually advocating wearing a sombrero, but with my thinness of natural scalp protection I’m very careful to have a hat handy whenever I’m out and about. I started a modest collection of hats when I was auditing foreign countries for USDA and fell in love with these: https://akubra.com.au/. My Favorites are my Coolabah in khaki and my Tablelelands in sand.
Wow. Those are some serious hats. I’ve never worn a hat remotely like any of them and would have a hard time choosing. So many of them give off an Indiana Jones vibe to me.
I wonder how they do at handstand pushups? Both are nice shots, Mike.
Handstand pushups? I suspect it would be no problem for them, though their legs look pretty skinny and not well-muscled like those of male gymnasts.
I find it so interesting that you were able to get the blue dasher image just like the guys in the laboratory! I keep seeing what I think are amber wings in our neighborhood, but so far none in this pose. Of course, I cannot see a dragonfly or damselfly and not think of you!
Thanks, Molly, for stopping to check out the dragonflies, which I love to watch, and for thinking of me. This month, it seems like I have photographed as many butterflies as dragonflies and definitely have heard no complaints from viewers. 🙂
[…] Read more about this behavior at fellow blogger Mike Powell’s post “Obelisk posture.“ […]