I guess just about everyone is familiar with dragonflies. If there's a body of water near you then you probably see them there. Here in Missouri I can't think of even one creek, river, or lake that doesn't have at least one or two resident species . And unlike some other insects they're usually pretty conspicuous. If they're around, you'll see them. So unless you live in the land of permanent ice and snow or smack in the middle of a desert then you probably know them well.
They are of course, insects, in the order Odonata, and like all good insects, they have six strong legs which ironically, as near as I can tell anyway, are seldom, if ever, used for walking. I can't recall ever seeing one take so much as a single step. But far from being useless appendages, their legs are very important for other things such as catching and holding prey, perching, and mating. Many species have spines along their legs which no doubt are very useful when clutching struggling prey species.
But why walk when you can fly anyway? With two powerful sets of wings, there's really not much need for walking. If you've spent much time trying to photograph them you may have come to the same conclusion I have that they spend more time in the air than they do on the ground. I read that some species can and often do spend an entire day on the wing without landing until it's time to bed down for the night. I have no reason to doubt it. They are truly remarkable fliers, in fact, some of the best in the entire animal kingdom. Almost all aspects of their life are connected to their amazing flight capabilities. Hunting, eating, mating, and egg laying are all done, at least to some extent, on the wing.
Although almost everyone is aware that monarch butterflies make a long annual migration , far fewer know that many dragonflies migrate as well. There is some evidence, though somewhat circumstantial at this point, that one species, Pantala flavescens, makes a round-trip migration of 11,000 miles, which if verified, would make it the longest known migration of any insect. How many millions of times would those those tiny wings need to flap up and down on a journey like that?
Those fragile looking wings are truly aerodynamic wonders. In spite of being paper thin and lightweight, they're extremely strong and weather resistant, with the added benefit that they're able to move independently of each other. This gives them the ability to fly in any and all directions, forwards, backwards, up or down, even sideways. Hovering is child's play. Just try keeping your eyes on one as it zips back and forth out in front of you. Maybe you can do it but I sure can't, and it's not for lack of trying. Now ya see em, poof, now ya don't. They routinely make full speed instantaneous directional changes that I suspect would rip the wings right off the most sophisticated combat aircraft ever constructed.
Those wings, along with their incredible eyesight and what I personally believe to be some level of intelligence not normally associated with insects, put them in the running to win the most deadly predator on the planet award, winged or otherwise. Curious, I looked around a bit but wasn't able to come up with much information on the chase to kill ratios of other predators. Lot's of opinions (which varied widely) but little in the way of hard facts but what little I did find said that most predators, even those "perfect predators" at the very top of the food chain such as sharks who've been evolving and honing their skills and tactics for hundreds of millions of years, or even those that hunt in prides or packs such as lions or wolves, have kill ratios that seldom exceed 25 to 50%. But in a study done using high speed cameras, dragonflies had an astonishing success rate of about 95%. This puts them in a class of their own.
One very significant advantage they have over other predators, including most winged ones, is their ability to not only visually track potential prey, even when that prey is flying in a large group, but at the same time calculate the trajectory and speed needed to to actually intercept it. And it does this instantaneously. In other words, while a Cooper hawk relies on it's ability to chase down and basically outrun it's prey, a dragonfly somehow figures out where that prey will be and then gets there first. And with a typical attack coming from behind and below, the victim may not even know it's in danger until it finds itself in the dragonfly's clutches.
To me the thought processes needed to make those calculations are mind boggling. I know that
many most people automatically attribute those kinds of actions to some sort of innate instinct but I have a hunch that something more might be going on. Just a hunch as I said but it's one based on a lifetime of observing. But that's gettin off track here so nuff said about that,.....arguing the possible degrees of intelligence in other species tends to bring out the crazy in me
As I mentioned, they have incredible eyesight and it's their eyes that first drew me to them. Look at a dragonfly's head and that's pretty much all you see, two very large, beautiful eyes. Along with bees they have the largest compound eyes in the insect world, each one consisting of up to 30,000 separate facets. Combine that with a field of vision of almost a full 360 degrees and you can understand why they're so hard to sneak up on.
I was drawn to them as a very young boy, they were one of the first insects to catch my eye, and to this day they still grab my attention whenever I see them. I wouldn't even try to guess how many hours I've idled away on the water, drifting down rivers or just sitting on the bank and all that "wasted" time automatically led to hundreds, if not thousands of dragonfly observations. But unfortunately, I never studied them in any serious scientific way, (a fact which I now regret) so I don't even remotely resemble an honest to goodness dragonfly expert. I've just always enjoyed seeing and watching (and now photographing) them.
But even without any conscious effort to study them I couldn't help but notice a couple of things about them along the way. One of those was that they seem to have favorite perches. I've learned that if I clumsily scare one away while trying to get close enough for a picture, I just need to get into position, sit still, and wait a bit because it will very often return to the same place, often sitting in the exact same position and I'll be able to get my picture. I imagine a lot of you are already aware of that, but if not, give it a try next time you're trying to photograph or just get a closer look at one and see if it doesn't work. It's not fool proof of course but it works often enough to make it worth a try.
Another thing I've noticed is that at most times those favored perches are vigorously defended against any other dragonflies that dare to venture too close. But other times I see just the opposite thing take place with two or even three sharing the same twig. It seemed an interesting contradiction and puzzled me for awhile, but after thinking about it a bit I realized it's not really any different than the actions of many higher animals which may get along or at least tolerate each other for most of the year, but become very aggressive once mating season rolls around. Just about everything gets territorial when sex is in the air. And in the world of the dragonfly, that translates to most of the time.
Much of a dragonfly's behavior is closely tied to it's mating process, which has some very unique aspects which are shared by no other insects. Different species each have their own methods, no two species go about it quite the same way and to go into much detail on the differences would require a whole separate diary. It's a fascinating subject and worth learning about but for now I better just give a general overview of the process.
The first step in dragonfly reproduction is one of the strangest in the animal world and involves only the male. He actually has two separate sets of genitalia, one near the tip of his abdomen where you might expect it to be and yet another secondary set just behind his head on the bottom of the second abdominal segment. Before he can mate with a female he must first transfer his sperm from the tip to his abdomen to a pouch-like structure in the second segment. If you've ever seen a male dragonfly with his abdomen bent under him with the tip touching the second segment and wondered what he was up to, now you know. Keep your eye on him because he has love on his mind and you may soon witness a mating. Very likely he has spotted a potential mate in the area and is making preparations. As far as I know all male dragonflies share this strange characteristic.
The actual mating and subsequent egg laying take many different forms depending on species. It is initiated by the male in all the species I've read about and there doesn't appear to be a lot of romance or courtship involved. Typically a male will fly to a female and capture her with his legs. He then grasps the back of her head with a powerful set of claspers on the tip of his abdomen. The males of some species are quite rough, and sometimes actually injure the females by biting and grasping them so hard. In spite of all that, once they are thus coupled, the female then inserts the tip of her abdomen into the secondary genitalia of the male where his sperm is now stored. This is the "wheel" position that most of us associate with mating Odonata.
While most matings initially begin in the air and some species complete the entire process there, others, once they're joined together, are led by the male to an area where they can land and finish mating without being harassed by other males. After the mating some species split up and go their separate ways immediately but most remain together in various ways for a certain period of time afterwards. In some species the male actually stays physically attached to the female, holding onto her with his claspers until she has completed her egg laying. Green darners are the only ones around here that I've been able to identify doing this but there may well be others that do the same. My eyesight is nothing to brag about and unless they're sitting still, I have trouble IDing most of them. Other species don't remain physically attached to each other after mating but the male does stand guard nearby, keeping the female always in sight, either hovering or more often, standing lookout on a handy twig or plant stem, until she has finished. This is what I see most often around here.
During this time the males are extremely aggressive and expend a great deal of energy endlessly chasing away one male after another for as long as "his" female continues to lay her eggs. There's a very good reason for a male dragonfly to so aggressively protect a female that he's just mated with. This relates to yet another very strange aspect of dragonfly sex. If given the opportunity, other males are capable of actually removing the sperm from any previous matings and then depositing their own in it's place. And as it turns out, this happens quite often. Females are capable of storing the sperm until it's needed and if many males are fighting over her this alone may be one trigger that would put her in the holding mode. There are obvious benefits to the offspring (and thus the species) in having a strong, able bodied male fertilize the eggs. So fighting for and winning a female and then mating with her is only the first step to passing on his genes. He then has to make certain that another male doesn't come in and undo the whole thing. It isn't over until the last egg has been laid.
The females of individual species each have their own specific egg laying methods as well. Some simply fly around dropping and scattering the eggs across the surface of the water. Some females survey the area for potential egg laying sites beforehand but others are physically led around by the males and he chooses where she will lay her eggs. Others hover just above the surface while dipping their abdomens into the water where the eggs are quickly washed out and released. At least one species that I read about lays her eggs in the mud right at the waters edge in the fall where they lie more or less dormant through winter waiting to be washed into the water the following spring when the water levels normally rise. Others seek out very shallow areas where they can insert their abdomen into the wet mud just below the surface. Some species, like the Green darners I mentioned earlier, take it one step further by inserting their knife-like ovipositor into the stems of underwater vegetation where the eggs will be a bit more protected. But that's the pinnacle of motherly love in the dragonfly world. No matter which species, once the eggs are laid they're completely on their own.
Those that survive their egg-hood and hatch still have to run a gauntlet of predators that will claim many before they are ready to leave their watery nursery. But those that manage to avoid ending up in the belly of a bullfrog or becoming fish food will eventually become adult dragonflies. How long that takes depends on the species and also on food availability. Some will become adult dragonflies in as little as three or four weeks while others may spend several years under water in their larval form.
The larvae, known collectively as nymphs or naiads, are quite interesting themselves. Like their parents they're voracious and efficient predators. They feed for the most part on other aquatic invertebrates but I've read that the larger species will even prey on tiny fish and tadpoles when the opportunity presents itself. Different species have different hunting methods. Some hunt by simply laying low, allowing silt and debris to cover and camouflage them as they wait to ambush any hapless victim that comes by. Some actually burrow into the bottom leaving just their eyes and the tip of their abdomen sticking out. Others are stalkers, creeping cat-like along the bottom until they are within striking distance.
No matter which way they approach the hunt, all species make the actual capture in the same way. Their lower lip is not only toothed but extendable up to a third of their body length and they can snap this out with the speed of rattler's strike. Anything in range of that strike is doomed.
Like most water born animals, they breath through gills, which in the case of dragonfly nymphs are located in their abdomen. They draw water in through their rectum and when necessary can expel it with enough force to thrust them forward thus becoming jet propelled, a handy tool for hunting or when being eyed by a hungry fish I suspect.
On their way to adulthood they'll go through several molts, shedding their old skins as they grow, up to a dozen times, depending again on species. If they manage to avoid all the predators long enough, the day eventually comes when they'll leave the water, usually by crawling up the stem of some emergent vegetation. Here they'll sit quietly waiting for their outer skin to dry out and crack open allowing them to crawl out of their skin one last time, this time as an adult dragonfly. This may take a few minutes or in some cases, up to several hours to complete and often takes place at night when they're less apt to be found by any of the many predators that have them on the menu.
This is the most dangerous time in a dragonfly's life. They're soft bodied and flightless until their wings fill out and dry, making them very vulnerable and desirable prey to anything that eats them, which is just about everything that you might expect to find in that habitat. Birds of many kinds of course, and raccoons, mink, otters, frogs, toads, turtles, lizards, snakes, fish, even other insects, including other dragonflies, are all potential predators. I read that the survival rate of newly emerged dragonflies can be as low as ten percent.
When they first emerge, during the teneral stage as it is called, most species lack the color and markings of their parents , or at best are a drab pale version of them and won't develop the brighter colors and markings of adults for several days or even longer in some species. During this transition period it can be difficult to ID them as many of them look similar. And in many species newly emerged dragons of either sex often resemble pale adult females. But as they mature the markings and colors of the males gradually correct themselves. In most species, once they are fully mature adults, the males and females look quite different from one another, often in both color and wing patterns, and are easily sexed.
They don't appear to be picky eaters and as far as I can tell, readily eat whatever they can catch. I've never witnessed one actually in the act of catching something, probably because it happens so fast that I couldn't follow it. But I've come upon several of them over the years that had just recently done so and were still in the process of eating their prey. Sometimes there isn't enough remaining to tell what it had been but I've been able to identify with certainty at one or more times, the following prey items; butterflies, moths, bees, flies, damselflies, and even other dragons. But I've read that midges, mosquitoes, gnats, and similar are actually the favored foods of most species. They catch and eat these smaller prey items on the wing without even landing to eat them so I've very likely seen them catching and eating those too but I wouldn't have been able to see something that small so probably wouldn't have even realized what I was watching.
Although they're usually found on or near the water, it's not at all unusual to find them quite far from it as well. They are roving predators after all, and can travel as far they need to in search of prey. Around here any open field, particularly harvested hay fields, seem to be popular hunting grounds. A few times I've seen a hundred or more, (who can count flying dragonflies?) hunting over fields more or less as a unit. Whenever I've seen this I've never been able to see anything that looked like prey, but I suspect there was in fact, an abundance of it, something too small for me to see, like midges or mosquitoes as I mentioned above. It just makes sense that there must be a whole lot of edible somethings out there in those situations to have attracted so many dragonflies.
The other possible explanation for those large gatherings is that some species do migrate and some even migrate together in large swarms. But the swarms that I've observed weren't traveling in any specific direction, just back and forth over fields or bodies of water, so my best guess is that they were drawn there because of an abundant prey item, most likely some kind of hatch taking place where hundreds or thousands of tiny, newly hatched insects are taking wing for the first time. It's also possible that those large gatherings are in fact migrating dragons that have temporarily pulled off their highway in the sky to fuel up when they happened upon such a hatch. I need to take note of the date when I observe those in the future.
One other thing I'd like to note is that although they are somewhat tolerant of pollution, when compared to dobsonflies, stoneflies, and caddisflies, if you see good numbers of them then you can feel pretty confident that that particular stream or river is healthy. On the other hand, if they are completely absent or you notice a decline in their numbers over time then there may be reason for concern. Along with the other invertebrates I mentioned they are a fairly reliable way to determine the overall health of that particular water system.
In the spring of 2012 I began taking pictures of any dragonflies that I came across in my wanderings. The way things are going I'm not too sure what the future holds for dragonflies (or any other inhabitants of this planet) and I just wanted a visual record of what once lived here in case things go from bad to worse over the coming years. Since then I've taken literally hundreds of pictures of them and out of those I believe I've identified 31 separate species as of today. Depending on which checklist you go by there are somewhere between 89 and 95 species of record in Missouri. Which means I've only found about a third of them, which means, of course, I'll have to spend a lot more time exploring Missouri's waterways. Dang the bad luck. Below the fold is a sampling of the ones I've found so far.
Keep in mind that I'm no expert on dragonflies and because of similarities between species and many possible variations within the species themselves, sorting out what's what can be difficult even for those that are specialists in the field. In fact there are many dragonflies that simply can't be identified all the way down to exact species through photographs, requiring either dissection or at the least to be examined under a hand held lens.
I've tried hard to correctly ID these but I should tell you that a few of these are best guesses made based on a set of criteria involving appearance, range, and dates of observation. I've been known to make mistakes before and it's very
possible likely that I've made one or two here. The Gomphidae family in particular can be extremely tough to sort out. I can only say for sure that these are all ID'd to the best of my ability. In species where there are noticeable differences between males and females I've posted pictures of each if I had them. They're labeled by Family, Genus, and Species, followed by their common name if known. I've also included a few extra photos that I just thought were interesting. I Hope you enjoy them as much as I do.
Thanks to all who managed to wade through the whole diary which did get longer than I intended, in spite of the fact that I really only scratched the surface of the world of the dragonflies. I actually started this as a Daily Bucket but it grew a bit big to fit into the normal bucket parameters so I abandoned that idea and will just publish as a regular BYS diary. Still hoping to put together a butterfly photo diary before the end of the year. If I do manage to get it done, I promise to make it an easier read. More pics, less text. ( :
My ID on this one is shaky at best and is very tentative at this point. I thought about not including it at all, but since I'm fairly certain that it is a different species, even if I'm not sure which one, I decided to put it in. The only thing I found that was close to it was an eastern clubtail still in the teneral phase, so that's what I'm calling it for now but if I don't have any more luck IDing with this one in the future, I'll eventually submit it to BugGuide and see if an expert can sort it out.
Gomphidae-Stylogomphus albistylus-Eastern Least Clubtail