It turns out a broken ankle really cramps my style. Despite that, I managed to get out into the prairie a few times this week. While I’m pretty slow, spring is progressing at lightning speed.
Green grass is spurting up through last year’s thatch, flowers are erupting here and there, and most grassland breeding birds have returned, filling the air with song. I paused a few minutes to watch some mound building ants this week, and their frenetic activity matched the crazy speed of the prairie all around them, as both plants and animals seem to be rushing to make up for lost time after an extra long winter. Last night, a big spring thunderstorm passed through, bringing much needed moisture, and adding even more wild energy to the landscape.
Here are a few photos I managed to get this week. If you haven’t already, get out and visit a prairie near you. Things are HAPPENING!!
Most of us don’t think about ants very often unless they’re marching across our kitchen counter (or up our leg). That anonymity isn’t their fault, it’s ours. Ants play major roles in ecoystems, and their biomass in prairies can rival that of bison, so if we’re not paying them sufficient attention, that’s on us.
I took the two ant photos in this post at the Niobrara Valley Preserve back in June of this year. As is usually the case, I spotted the ants only because they happened to be crawling around on some flowers I was looking at. Ants are often spotted on flowers, especially those that have easily accessible nectar that helps satisfies ants’ attraction to sweets. While they don’t usually do much good as pollinators, ants might provide some protective services for plants by helping to keep herbivores away.
Ants spend most of their time underground, of course, where it’s easy for us to forget about them. When they’re not in their tunnels, they still aren’t all that visible unless we’re looking for them. Regardless, they are major predators in prairies, collaborating with each other to take down prey much larger than they are. In addition, ants are scavengers, major forces in nutrient cycling, and important seed dispersal agents for some plant species. Ants can also steal food and workers from each others’ colonies, “herd” aphids and harvest their honeydew and meat, and are themselves an important food source for other animals. We should probably stop ignoring them.
Most prairies probably have around 30 species of ants living in them, which is more local diversity than is found in grassland nesting birds, which we pay infinitely more attention to. In addition, if we lost all our grassland birds tomorrow, it would be sad, but I’m pretty sure it would have much less impact on prairie ecosystems than if we lost our ants.
Let’s try to keep them both around, shall we?
Here are some previous posts I’ve written about ants if you feel like reading a little more about them:
(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.
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.
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.
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!
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.
Last week started with beautifully warm weather. Plants, such as this Penstemon grandiflorus, were rapidly sending up tender leaves, eager to rebuild their energy reserves with the sun’s rays.
On a 60 degree Sunday, I was shocked to stumble upon an ant colony hectically rebuilding their nest.
I was repairing a bridge in a muddy part of the prairie on Monday when I noticed a couple puddles no bigger than iPhones. To my amazement, they were brimming with all sorts of life. I lay on my stomach and watched them for several minutes, but I probably could’ve spent an hour staring into them. It amazes me how much life a tiny scrape in the ground can contain, and how quickly that life materializes with a little bit of sun and water. How did so many minute creatures endure a freezing winter and explode so quickly with abundance? My guess is that they spent the winter as eggs in the soil and quickly hatched when the puddle filled with water. But with the very imminent threats of freezing or drying out, these critters must reproduce very quickly. Maybe that’s why they seemed so frantic. (I checked on the puddle yesterday and it was dry. I hope they got done what they needed to!)
While the warm weather ushered in many new species, it also encouraged the cranes to start leaving, sadly. As I watched the puddle critters, flocks of cranes circled on thermals high into the sky before catching southern winds and continuing on their journey north.
Of course, spring is fickle in nature. By Monday, a cold front produced a spectacular lightning storm that rolled over the prairie.
In the days following the storm, the temperature plunged. Cold mornings frosted the tender leaves of plants that had sprouted under more encouraging conditions just days before. I don’t know how plants and animals survive such unpredictable weather at such a vulnerable stage in their lives, yet somehow they do it year after year.
I first noticed the dead ants about a year ago, when James Trager was visiting our Platte River Prairies to help us see our grassland through the eyes of ants. As we poked around the prairie together we kept seeing ants that were stuck and dying on the flowers of two native thistle species (Flodman’s thistle – Cirsium flodmanii and Wavyleaf thistle – Cirsium undulatum).
The ants didn’t appear to be getting stuck on the numerous spines on the flowers. Instead, they were getting caught by the flypaper-like stickiness of the lower portion of the flower as they tried to crawl up toward the nectar and pollen at the top. While ants are definitely the most common victim of these flower traps, I’ve also seen bees, flies, and a few crab spiders get caught as well.
It’s interesting to speculate whether or not ant trapping is a strategic adaptation the flowers have developed over time or just an unlucky accident for the ants. Ants are not particularly effective pollinators, so it would make sense for thistles to evolve a strategy that helps prevent ants from “stealing” their pollen and nectar. Since more effective pollinators such as bees and flies come to the flowers by air, stickiness of the lower portions of flowers wouldn’t affect them much (the above photo notwithstanding). Ants have to get to the flowers by crawling, so a sticky zone between the ground and the pollen might be a very effective strategy for ant prevention.
The stickiness of thistle flowers is an interesting counterpoint to the extrafloral nectar produced by plant species such as sunflowers. Sunflowers seem to produce that substance to ATTRACT ants – presumably to help ward off potential herbivores. Thistles may be producing a substance to keep ants AWAY. Very interesting.
Or it could just be a complete accident – which is not a very good story, and sort of sad.
If you’ve followed this blog for a while, you know that we’re trying to inventory the ant and bee species (and others) in our Platte River Prairies. Our main purpose is to see whether or not our restored prairies are providing habitat for the insect species living in our remnant prairies. If they are, it’s likely that we’re succeeding in our attempt to use restoration to enlarge and reconnect fragmented prairies. Last fall, I posted the results of the brief survey James Trager helped us with in the summer of 2012. At that point, we’d found 22 species.
During a prescribed fire last week, we found a big ant mound. The ants were understandably agitated by the fire… I noted the location of the mound and went back the next day with my camera (and my new flash kit!) to get some photos. I emailed James the photos to see if he could identify the ant species, and of course he could – Formica obscuriventris. More importantly, it wasn’t a species we’d found last summer, so I could add it to our list!
The mound was in a restored prairie, which was good to see. Of the 23 species we’ve found so far now, 4 of them are tree-dwellers and 19 are prairie ants. Of the 19 prairie ant species, we have found 14 in restored prairie. I’m hoping we just haven’t looked hard enough to find the other 5 in restored prairie (very possible, given our limited sampling effort so far). If that turns out to be true, it would be a great indication that our restored prairies are acting as new habitat for those ants, and enlarging/reconnecting formerly fragmented prairies.
I’m sure many of you could have identified this ant species without James’ help, but I couldn’t and am grateful to him. He pointed out that it’s the boxy cross-section of the clypeus that separates this species from a couple other possibilities. …But you probably already knew that…
For those of you interested in the photography side of this, I photographed the ants with a 105mm Nikon macro lens on a Nikon D300s camera. The images above are variously cropped to show the ants better.
It was a partly cloudy day, and the light kept switching from dark cloudy to bright sunny – neither of which was great for photography. To mitigate that, I used a diffuser (thin white cloth on a big collapsable plastic circle about 2 ft in diameter) to reduce the light when the sun popped out and then used flash to fill in the rest of the light needed to use a fast shutter speed. My flash kit is a Nikon R1 Close-up Speedlight system, which has two small flashes – mounted on either side of the lens.
…I might start to like this whole flash photography thing.
Well, as promised, here are some early impressions from the time I spent looking around our Platte River Prairies with Mike Arduser (bees) and James Trager (ants) last week. I’ll know a lot more after Mike and James have time to sort through the all the insects we collected. Both have promised to send me annotated lists of the species we found, along with the locations each was found in. Once I get that information, the three of us will be able to have some more discussions about what the data tell us about the state of our prairies – from the perspective of bees and ants. It’s unlikely that our single snapshot of data collection will provide us with any major conclusions, but I have high hopes that our efforts will point out some paths I can follow during the next couple of years to flesh out the story.
The Platte River Prairies through the eyes of bees:
Obviously, plant diversity is important to bees, but the majority of bee activity last week seemed to be taking place on purple prairie clover, a species that is pretty abundant in both our remnant and restored prairies. I don’t know yet how many of the 40 or so bee species we collected were found (at least once) on prairie clover, but I bet it was at least 30%. In addition to purple prairie clover, hoary vervain was another fairly heavily used species (though nothing like the clover). In some ways, then, a few very accessible and productive flowering species seem to play a huge role in supporting bees – especially generalist species – in our prairies during this time of year. From talking with Mike, it sounds like that kind of heavy use of a few species is fairly common in other prairies he’s seen.
On the other side of the coin, roughly half of the bee species in our prairies (and most other prairies, I think) are specialist pollinators on a single species, or small group of species of flower. For these bees, the abundance and distribution of their particular host plants is obviously critical. We found bees that specialize on a number of different flowers, including those in the genera Callirhoe (poppy mallow), Physalis (Ground cherry), and Oenothera (evening primrose), among others. There were also a fair number of bees with slightly broader, but still restricted, diets. Many of the flowers used by specialist bees have other pollinators to help them produce seed, so the relationship is usually more critical to the bees than the flowers – though that’s not universally true. Some, like the ground cherries, have flower types that can’t easily be pollinated by insects other than those built to specialize on them.
Mike and I spent some time talking about our need to know more about what thresholds of flower abundance and distribution are really important for these specialist bees. For example, a prairie that has only a couple individual plants of ground cherry isn’t likely to be able to support a bee species that can only use that kind of plant. But how many plants does an individual bee need to raise a brood? And how close together do those plants need to be in order for bees to find and pollinate them efficiently?
From the plant species’ standpoint, how many individual plants (and at what density?) does it take to attract enough pollinators to provide sufficient pollination for the plant population? It’s a particularly important question when talking about rare plants, which often occur in small scattered populations. It’s also important for our degraded remnant prairies that have very few individuals of even some more common plant species. If we don’t have enough plants to garner effective pollination, the population may not reproduce – or sustain itself in the prairie. It makes me think about the way we approach our overseeding efforts in those degraded prairies. Maybe we need to be using lots of seed in small areas to establish patches of flowers with enough density to attract pollinators, rather than spreading that seed more lightly across large areas. Very thought provoking. I need do some investigation, and see whether we’re getting seed production from plants that are scattered at low densities across degraded remnant prairies.
Mike needs to spend some more time looking at the data we collected this week to see if there are differences in the bee communities between our restored and remnant prairies. We spent quite a bit of effort collecting bees from purple prairie clover and hoary vervain across a range of restored and remnant sites in the hope that we could see whether or not the same bee species were visiting the flowers in both site types. Granted, we only had about three good days of field data collection to draw conclusions from, but I hope it was enough to give us at least an initial glance at what’s going on. To do it right, of course, we’d need to look at the abundance and density of plants at each site, and focus on more than just the number of bee species using them at each site – the number of total daily visits, for example, would also be important, as would seed production and other measures. I’m hoping to collect some more bees throughout the rest of this season to give us a bigger slice of the total picture to look at. It’d be great to see a pattern interesting enough that we can build a graduate student project out of this, and take a much closer look at what’s happening. Anyone looking for a good project?
Again, Mike still needs to finish sorting through and identifying the bees we collected this week. However, he did notice a few interesting discrepancies between what he expected to see at our sites and what we actually found. For example, we really didn’t see many (any?) twig-nesting bees, and only two species of parasitic bees. At this point, it’s hard to know if that’s because the bee fauna here is just different than what he’s used to seeing further east, if our sample was too small to fairly represent what’s actually here, or if there’s something functionally missing from our prairies.
On the other hand, there were a fair number of bee species that are rare in Missouri and other eastern prairie states, but common in our prairies here. One of those is often called the “ghost bee” because of its fuzzy white appearance and the difficulty of finding it in eastern tallgrass prairie. When Mike saw one in my net on our first day of sampling, I could tell from his expression that it wasn’t just another fuzzy bee… Unfortunately, after I came home that night and bragged to my family (who didn’t seem that excited) that I’d caught the elusive ghost bee, we ended up seeing them pretty often during the rest of the week – somewhat dampening my sense of accomplishment. And, just to rub it in further, during our public field day on Friday, two Pheasants Forever biologists showed Mike some very nice photos they’d taken of the same bee species from another prairie about an hour north of us. Sure, it’s great to know that the species appears to be doing well in this part of the world, but it did knock the air out of my balloon a little… On the other hand, how great is it that there are Pheasants Forever biologists out taking photos of bees in prairies?! Awesome.
What about ants?
It turns out that ants provide an interesting contrast to bees in terms of how they perceive prairie “quality”. While the diversity and abundance of bees in a prairie is heavily dependent on the diversity of flower plants, ants tend to look more at habitat structure than at plant species. For example, James says that one very important attribute of prairies is the attractiveness of its habitat for recently-mated females looking for a place to start a new colony. One significant factor for those females is the presence of enough bare ground to allow them to see whether or not an area is already occupied by colonies of potential competitors. More broadly, prairies that are most attractive to ants tend to be those that have a lot of variation in plant density and structure. Prairies that are dominated mainly by grasses are usually too homogenous to be very ant-friendly. So, while ants might not respond directly to plant diversity, prairies with good plant diversity may be more likely to have the kind of structural diversity that ants are looking for.
After seeing the kind of fire and grazing management we’re using on our sites, James’ opinion was that we’re probably doing a pretty good job of facilitating ant habitat. Our grazing helps create the kind of structural variation that ants tend to like, and our stocking rates are light enough that we aren’t likely to be compacting the soil to the extent that it might negatively impact them. However, as with Mike, James only had a few days to look at our prairies and the ants living there, so it’s hard to draw too many conclusions – and he still needs to finish sorting and analyzing the data we collected this week.
James, along with Laura Winkler, a graduate student from South Dakota State University who joined us for the week, caught about twenty ant species in our prairies. They collected some of those ants by just walking around and looking for them. Other ants were found by setting pitfall traps or laying out baits that ranged from chicken skins and canned meat to pecan cookies. From his initial impressions, James said we had a surprisingly high abundance of a few ant species, but there were at least a couple of ant species he expected to be common here that we never saw. It’s hard to know whether that’s because they’re really not here or because we just missed them during our limited sampling time. In general, however, James felt that we might be missing some of the more common eastern prairie ants, and he wasn’t seeing western species that he would have expected to fill the same kinds of roles. If that’s an accurate picture of the ant communities in our prairies, it makes me wonder whether that’s just the way prairies in our part of Nebraska are, or if there is something going on that we should be addressing. I guess I’ll wait to hear more from James before I start worrying too much about it…
Because of the limited time we had, and the great variation in management and soil types across our prairies (not to mention this summer’s drought) it wasn’t really possible to do a good direct comparison of the ant communities between our remnant and restored prairies. However, I hope that James’ data might still give us some hints about whether or not there is something to follow up on in that regard. Because I know our restored prairies have some soil characteristics that are pretty different from remnant prairies that haven’t been farmed, I expect there to be some differences. Whether or not they’re important differences – or correctable – is something I don’t know…yet.
I’m extremely grateful to both Mike and James – as well as Laura – for giving up an entire week of their time to come out to explore our prairies and help me learn to think differently about them. As always happens when I spend time with intelligent people who are experts in their particular subject matter, I was awed both by their level of knowledge and the complexity of the worlds they study. Everywhere we looked, Mike and James shared fascinating stories about nearly every insect that flew or crawled by. In addition, both were very knowledgeable about ecology in general, which led to fantastic discussions about much broader topics than just invertebrates. It was a week that will keep my brain buzzing for a very long time, and I can’t thank them enough for coming.
I’ll keep you updated as I get more information and have some time to synthesize it…
This is my week to learn everything I can from James Trager and Mike Arduser – entomologists and ecologists from Missouri. They (and their wives!) have very graciously agreed to spend the week in our Platte River Prairies to help inventory our insects, try to teach me a few things, and brainstorm ways I can evaluate our prairie restoration and management work from the perspective of insects. It’s going to be a great and busy week.
We started the week yesterday in Pawnee County, Nebraska (southeast corner of the state). Pawnee County was on the way to our Platte River Prairies, so I met James and Mike down there and we spent the morning looking around. Both James and Mike have helped identify insects from those prairies for various research projects I’ve been involved with, so it was good for them to be able to see some of the prairies those insect samples had come from. It was a little wet for collecting many insects yesterday, but we got to visit some interesting prairies and had some good discussions. We were joined by Kent Pfeiffer and Krista Lang of Northern Prairies Land Trust, and Bethany Teeters, a PhD student at the University of Nebraska.
Even in the first hour or two in the prairies, it was clear that I’m going to learn a tremendous amount this week. James and Mike were definitely seeing the prairies through different lenses than I was, and noticing insects and habitat qualities I wouldn’t have thought about. Back in graduate school, I studied the impacts of habitat fragmentation on grassland birds, and I remember beginning to look at prairies differently as I learned more about how birds evaluate them. I can see that I’ll be doing some similar perspective shifting again this week.
For those of you coming to our field day this Friday, you’ll have a chance to meet and interact with Mike and James – and other experts. For the rest of you, I’ll try to capture some of the big lessons from the week in future blog posts.
Thank you to Kent, Krista, and Bethany for taking the time to help show Mike and James (and me!) around the prairies yesterday. Also, thank you to Prairie Biotic Research Inc. for the grant that is helping to fund the travel costs for Mike and James to come work with me this week.
PLEASE JOIN US for a Platte River Prairies Field Day on July 13, 2012. The day will include a range of activities, aimed to introduce relative newcomers to what prairies are all about and to allow more experienced prairie biologists/naturalists a chance to interact with a wide range of grassland experts. This is an event that is designed for both professional biologists and the general public. Spend the day with us and learn about prairie species, prairie restoration, and prairie management.
Throughout the day, there will be guided tours of our high-diversity prairie restoration work and fire/grazing prairie management, during which visitors can see the results firsthand and discuss the associated challenges and successes. We hope this will give people a chance to see some of the many options available for doing prairie restoration and management work and provide ideas that could be adapted to other sites. The objective is not to promote the specific techniques we’re currently using, but rather to share what we’ve learned along the way, and stimulate discussion among the group that helps all of us get better at prairie conservation.
In addition, we’ve lined up a number of experts on various topics, including prairie ants, spiders, bees, reptiles/amphibians, plants, invasive species, and wildlife management, and those experts will give field presentations on their topics – and will also participate in the tour discussions. This will be a great chance to learn how to identify prairie species you might not be familiar with, and also to learn how those species live and interact with each other. If you’re like me, it’s difficult to learn how to identify tricky species when there isn’t someone there to tell you whether or not you’re guessing right! Also, there’s no substitute for an in-person conversation with someone who is a recognized expert in their field of study.
There is no cost for attending the Field Day. We are grateful to Pheasants Forever and Prairie Biotic Research, Inc. for helping to cover the costs of the event. We will have some snacks available, and will keep big jugs of cold water, tea, and lemonade so you can fill your bottles as many times as you need to during the day. Please bring a lunch with you – we’ll provide places to sit and eat, and might even have a slideshow by some nature photographer or other during lunch time. In case it gets extraordinarily hot in the afternoon, we’ll have some indoor and shady activities planned as well.
Scheduled events will start at 9am and end at 4pm, but we encourage you to come early and stay late. Trails will be open all day, so you can feel free to explore the prairies on your own as much as you like. We would appreciate it if you would let us know if you plan to attend – so we can ensure we have enough snacks and drinks and so we can plan hikes accordingly – but you are also welcome to just stop by.
Click HERE to see the official announcement of this event on our website and to get more information. Be sure to click on “Show Directions” to get directions to the prairies. PLEASE NOTE THAT THE BRIDGES NORTH OF OUR PROPERTY ARE OUT, SO FOLLOW THE DIRECTIONS ON THE WEBSITE – DON’T ASSUME YOU CAN GET THERE AS YOU MAY HAVE IN THE PAST.
Here is a list of those people who have committed to help lead tours and/or present information at the Field Day. We are still pursuing a few more.
Mike Arduser, Missouri Dept of Conservation (bees)
Bill Beachly, Hastings College (spiders)
Pete Berthelsen, Pheasants Forever (wildlife management, pheasants/quail)
Karie Decker, Nebraska Invasive Species Program (invasives)
Dennis Ferraro, University of Nebraska (reptiles/amphibians)
Chris Helzer, The Nature Conservancy (prairie management)
Gerry Steinauer, Nebraska Game and Parks Commission (botany, prairie restoration)
James Trager, Shaw Nature Reserve – Missouri (ants)
About five years ago there was a major rainstorm in early May that dropped 12 inches on our Platte River Prairies within 24 hours, and flooded most of our sites for several days. I wasn’t too worried about most of the prairies (they’re floodplain prairies, after all, and should be used to flooding) but I was concerned about the influx of purple loosestrife from the out-of-bank river and about the fate of a few young prairie restoration seedings. A the same time, I was hoping the big rain would help end the drought we’d been in for more than five years (it didn’t).
As the prairies dried out, I started checking them to see how things looked. I was walking through a 5-year –old prairie seeding looking at the prairie plants, which were looking very good, when I suddenly noticed the ant hills. Everywhere I looked, there were ant hills. I couldn’t take a step without trampling one. I had a quick illogical thought that we’d been invaded by fire ants. Once my brain kicked back into gear, I realized that I was likely seeing the simultaneous rebuilding/repair of all the ant tunnels that had been in place prior to the big rain.
Ants are extremely important to prairies as predators and earth movers (and fill other roles as well) and I knew that they were really abundant, but until I saw the density of hills after that flood I didn’t really have a good idea HOW abundant they could be. After all, the hills are the tip of the iceberg, and only indicate the presence of numerous and extensive tunnels beneath the surface. Before writing this post, I contacted James Trager (Missouri Botanical Garden) to see what he could tell me about the phenomenon I’d observed.
James said he thought most the hills were probably made by Lasius neoniger, the “cornfield ant”, which is a very abundant species common to prairies with sandy soil. He also said ants can survive floods by finding refuge in air pockets within their underground nests. That’s something I hadn’t thought about either – all the invertebrates living belowground have to be able to survive saturated soils, especially in floodplain prairies.
I thought about using these photos and story as the basis for a larger post on prairie ants, but decided that it would be redundant. James has already written an excellent and succinct synthesis of the fascinating world of prairie ants. Rather than trying to steal his ideas and re-write them, I’ll simply give you the link to his. If you haven’t read his introduction to prairie ants, it’s well worth the few minutes it’ll take you to read it.