Swarms, Squadrons, and Skies

(See the note at the end of this post about our free Plant Identification workshop this Thursday – July 6, 2017)

Last week, my wife and I were both at the Niobrara Valley Preserve, working with other staff to evaluate some of our fire and grazing treatments.  We finished the bulk of the data collection by Wednesday, but Kim and I stuck around another couple days after the other visiting staff left.  On Wednesday evening, we both felt like spending some quiet time in the prairie by ourselves so we took off in opposite directions.  As it happened, neither of us got to be alone on our hikes.

I took my ATV up into the hills to find a nice place to walk with my camera as the sun went down, and as I was driving up the hill, I felt something me on the top of the head.  It felt like I was driving through tall grass that was slapping me gently as I drove through, but all the vegetation around me was knee high or less.  I couldn’t figure out what was going on until I stopped and got off the ATV.  At that point, I realized I was being swarmed by some kind of tiny insect.

Self portrait with swarming insects

It was an almost perfectly calm evening, and there were myriad hovering swarms of these insects scattered around the prairie – often over the top of fence posts or tall shrubs.  Whenever I came close to one of these swarms, it was like my head was a magnet; the whole swarm would kind of just SHLOOOP over to my head and use it as the center for their wild dance.  It was like having my head inside a bubble full of flying bugs. While I was having this surreal experience, Kim was dealing with the same phenomenon a mile away, as she walked along a two-track road through the bison pasture.

I was trying to photograph the beautiful sky and look for flowers or insects, but it was really hard to concentrate with a horde of little critters flying around and crawling about on my head.  They weren’t biting me, but they were awfully distracting.  If I moved fast enough (the ATV was handy…) I could get away from one swarm, but there were so many swarms around, it would just take a few moments after I stopped before another found me.  Once I figured out I wasn’t being attacked, I could relax a little and managed to get some photography done, but I was certainly less focused (ha ha) than normal.

The prairie and sky above it were absolutely gorgeous in the late day light.

I was, of course, also interested in what kinds of insects these were that were swarming around my head, but they were so tiny I couldn’t see them well enough to tell.  I could grab a few of them at a time and look, but I just couldn’t see enough features without some magnification.  They didn’t look like midges, which had been my first guess, but beyond that, I was stumped.  Finally, as I was getting ready to head back to the cabin, I caught a bigger one (a female, I assumed) and it looked a lot like a winged ant.  I took her and few other smaller ones back to the cabin in a little ziplock bag so I could look more closely at them.

The next morning, I pulled the insects out of the bag and used my macro lens to examine and photograph them.  Sure enough, they were tiny ants.

Two of the flying ants that had been swarming around us the previous night.

As I understand it, the kind of nuptial flights Kim and I experienced are often triggered by a combination of temperature and recent rains (it had rained the previous night).  Winged males and a few females take to the sky to chase each other around and mate.  Because of the huge number of flying insects in these swarms, they are an easy target for flying predators like dragonflies and birds.  Sure enough, Kim said she ran across bunch (flock? squadron?) of hunting dragonflies and they did a pretty good job of thinning the horde of ants around her head.  I didn’t think of looking for dragonflies.  Instead, as soon as the light dimmed and closed the photography window I hopped on the ATV and gunned it, enjoying a nice manufactured breeze all the way back to the cabin.

I wish the ants luck with their mating swarms.  We need ants, and if this is how we get more, then I hope they are successful.  At the same time, it’d be nice to have a schedule of when they plan the events so we can plan our quiet evening excursions accordingly…

REMINDER:  On July 6 (THIS THURSDAY!) we are hosting a Plant Identification workshop at the Platte River Prairies.  This is a free event.  Bring your own lunch and water bottle, but we’ll provide snacks and some cold drinks.  You can come and go anytime between 9am and 2pm.  We will have several expert botanists leading hikes through different habitat types and working with you to improve your plant identification skills.  Meet at The Nature Conservancy’s Derr House – 2 miles south of Interstate 80 Exit 300 (Wood River).  Immediately after the highway curves sharply to the east, turn south on the gravel road (Platte River Drive) and you’ll see the TNC sign and big brick house.  Don’t use your GPS, it’ll likely lead you astray.  See you Thursday!

Hubbard Fellowship Blog: Ant Swarm (and Lunch)

This post was written by Evan Barrientos, one of our Hubbard Fellows.  Evan is a talented writer and photographer and I encourage you to check out his personal blog. If you would like to see more of his photographs, you can follow him on Facebook.

Don’t worry, I didn’t eat a swarm of ants. But late last September while I was harvesting seeds I did notice enormous clouds of small flying insects swarming above the prairie. The swarms were constantly shifting shape but they were roughly the size of small cars slowly floating across the land. Intrigued, and slightly mesmerized, I walked directly beneath one.

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Closer up I could see that the mystery insects had very narrow waists, which suggested that they might be in the order Hymenoptera (ants, bees, and wasps). Their brown color made me think they might be flying ants.

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Then I began to notice several individuals crawling in the grass below the swarm. Some were caught in spider silk; not complete webs, but loose strands of silk. Looking around, I realized that there were dozens of silk strands scattered among the grasstops of the prairie. As I knelt to photograph one ensnared ant, I saw a small jumping spider stalking another. The spider crept up, grabbed the ant, and carried him away for lunch. Were these silk strands deliberate traps set by the jumping spiders or were they just remnants of ballooning juvenile spiders that happened to catch the ants? I still don’t know.

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Later, I sent the photo below to James Trager, an ant expert, and learned that these were in fact flying ants, Myrmica americana to be specific. It still AMAZES me that there are people who can identify insect species  from just one photo!  He explained that there are actually three different species that currently are all called M. americana because two have not been officially named yet. The unnamed species I encountered is very common, which shows how much we still have to learn about even the insects in our backyards.

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Not only did Trager know the species’ name, but also the explanation for their hypnotic swarming behavior. When it’s time for M. americana to reproduce,  winged males swarm together, forming what’s called a lek.  Reproductive females are drawn to the spectacle and watch from the leaves below. Males will periodically descend from the swarm to crawl around in search of females to mate with (or get snagged by spiders). If a male is lucky enough to avoid the predators below, he may find a female to copulate with. But the challenge doesn’t end there. Once a male begins copulating, dozens of other males will often swoop in and try to do the same, forming what’s called a “mating ball.” After the whole fiesta has ended, the female pulls out her wings (so that she can convert her wing muscle into food to feed her offspring via glandular secretions) and walks away in search of a place to start her own colony.

Finally, here’s a video of the lek, first at full speed, then in half-speed slow motion.