Photos of the Week – March 4, 2024

Just a quick note at the top: We are still working to fill our team at the Niobrara Valley Preserve in north-central Nebraska. The latest position we’ve posted will be focused on communication and outreach. The NVP Community Outreach Specialist will organize and host events and work with visitors. Much of their role will be focused on sharing what we’ve learned from our fire and grazing work, but they’ll help connect people to nature in other ways as well. To learn more, please go to nature.org/careers and search for job # 54793 (Community Outreach Specialist).

The 3rd of March in central Nebraska is not usually a great time to look for insects in the prairie. Even this year, following a pretty mild winter and lots of warm weather during the last few weeks, I wasn’t sure what I’d see when I headed to our family prairie this weekend. At first, when I arrived, I figured I’d have a pleasant wandering hike, but didn’t expect to take many photos. It was 60 degrees and mostly sunny, but it was only March 3, after all. There were a few little patches of green around, but most of the vegetation was very dry and brown.

Once I headed to some of the more heavily-grazed areas from last season, though, and sat down to focus more closely, I started to find movement. I saw a couple little flies first. Then, I noticed something hop. I wasn’t sure it had been a hop, actually, because the stiff breeze kept picking up little bits of dried plant and tossing them in front of me as I walked. Several times, I thought I’d seen an insect move but, upon closer inspection, it was just a seed, part of a leaf, or something else. This time, though, the hop had been legitimate, and it had been performed, appropriately, by a tiny grasshopper.

A tiny nymph of what I’m pretty sure is a kind of band-winged grasshopper hiding in the grass.

In fact, there were two or three little grasshopper nymphs within a foot or so of each other. I can’t tell you for sure whether there were two or three because they were incredibly hard to see – a combination of their diminutive size and their amazing camouflage. If I glanced away from one for just a second, I couldn’t find it again. Each nymph was about a half inch long and colored almost exactly like the dead grass around it, complete with dark mottling that helped blend with the shadows.

The only reason I could find the little nymphs at all was that the grass was short and there were enough patches of bare ground that I could see the movement. Even then, if one hopped more than an inch or two (which they did – repeatedly) I’d lose it. Then I had to start sweeping my hand back and forth above the grass, hoping to flush one up and then follow it through the air with my eyes until it landed. It was a poor strategy because I usually lost them once they landed, but it did work a couple times.

The prairie vegetation was largely dormant, except for a few sun sedges (Carex heliophila) and some smooth brome and Kentucky bluegrass. The more grazed areas had some bare ground that provided insects a place to bask in the sun (and where I had at least some opportunity to spot them).

Apart from a couple early-season invasive grasses (smooth brome and Kentucky bluegrass), the prairie plant community was visually dominated by drab-looking dried plants. In some places, sun sedge provided little flashes of green and there were a few tiny annual plant seedlings popping up here and there – especially in patches of bare soil. Stiff goldenrod’s basal leaves still had a little green left in them, and I saw a little yarrow and a few other plants that looked like they were starting to grow. I also visited my favorite patch of buffalo pea (Astragalus crassicarpus) and was pleased to see it starting to put on leaves.

Buffalo pea leaves were starting to unfurl themselves.

Once I started concentrating on the little patches of bare soil between plants, I began seeing more furtive movements. There were lots of really tiny juvenile wolf spiders scurrying around, for example. They’d zip forward half an inch and then pause for a few seconds or minutes, and then scoot forward again. As with the grasshoppers, their camouflage was so effective, I could only see them when they moved, and if I took my eyes off them at all I was unlikely to find them again. I lost several of them when I tried to put my camera up to my eye and focus. I don’t think the spiders moved. I think they just merged into the background and blinked out of sight.

This is one of the many little wolf spider juveniles moving around between plants. They measured about 1/4 inch (maybe) from the tips of their front legs to the tips of their rear legs.

No matter how slowly I walked around the prairie, I almost never found any insects (or spiders) unless I got down on my hands and knees. While walking, I noticed a flying tan-colored lacewing because the sun backlit its translucent wings, and sometimes I’d see a tiny fly scooting through the air between plants. Otherwise, my discoveries always came when my face was less than a foot from the ground.

I assume most invertebrate activity was concentrated where bare soil was exposed – especially on south-facing slopes which caught the sun and provided a little shelter from the stiff breeze. That would make sense based on the thermoregulation preferences of the little critters. On the other than, those were also the places where I spent my time because I had half a chance to find the buggers, so my sampling was pretty biased.

This little beetle was moving around on a big pile of bare soil sheltered from the wind by some trees behind the pond.
This was, by far, the biggest fly I found on my walk. It was about house fly-sized. Most of the others were maybe 1/10 that size.
I photographed several of these little annual plant seedlings before I started noticing the minute insect nymphs hanging out on them.
Here’s a cropped version of the photo above it. I feel like I should know what kind of insect this is, but I can’t come up with it. Help?

I ended up walking a loop that took me through all four pastures at the prairie, including some that had tall, dense vegetation and others with much shorter structure. I walked faster through the dense stuff because I knew I had less chance of finding inverts. As I got back toward my truck, I went prone again to see if I could find a few more grasshopper nymphs before I quit for the day. Sure enough, there were a couple there. That made me wonder if there was a grasshopper on every square foot of ground, but hidden so well that I hadn’t seen them. I doubt that, but I don’t dismiss the idea completely.

The last grasshopper nymph of the day.
The same nymph as above, but face-to-face.

Spring hasn’t sprung yet, but it felt like it was coiled and ready. It was fun finding insects, but I also wondered what an extra early start to the growing season would mean in the context of continued drought conditions. Warm weather at this time of the year often just gives invasive grasses time to pull the little moisture we get over the winter out of the soil before late spring wildflowers are able to access it. By summer, there might not be much water for plants unless we get better rains than we have for the last couple years.

The prairie will be fine either way, of course. As a photographer, my preference would be for lush growth of wildflowers and an abundance of invertebrates and other animals to chase with my camera. As an ecologist, I’ll enjoy watching the grassland exhibit its resilience, no matter what happens.

Is Prairie Stewardship Hampered By Our History Goggles?

I often think one of the biggest issues we face in grassland restoration and management is that we’re a little too stuck in the past.  This expresses itself in various ways, but I think it’s a nearly universal issue with everyone involved in prairie ecology and stewardship.  To one degree or another, we’re all looking backward.  Let me explain.

We’ve all stood on a hill and stared into the distance, trying to envision what that view would have been a few hundred years ago.

An obvious example of what I’m talking about appears in prairie restoration (reconstruction) when someone’s goal for a prairie planting project is to create a prairie that looks like it used to look a few hundred years ago.  I hear this a lot less than I used to, which is good, given the numerous problems with that goal.  However, even those of us who claim to be focused on more practical objectives can slip up sometimes.  It just feels good to recreate something from the past, especially when the past must have been so great!

The same romanticism for the old days affects our management, too.  Regardless of what our plan says (you’ve all got a clear, written management plan, right?), most of us can’t resist glancing around and wondering what a particular site must have looked like “back in the day”.  It’s real easy to for the resulting mental pictures to start influencing the way we evaluate the condition of a prairie and the direction we try to push things through stewardship actions.  We don’t really think we can get back to what it used to be, and yet

I see the impact of those “history goggles” all the time, both in my own head and during conversations with other prairie people.  One of the more frequent appearances comes during thinking or talking about plant community composition.  “Oh,” someone will say, “that wildflower used to be much more common before European settlement.” Or, similarly, “Those grass species never used to be as prominent when these prairies were surveyed in the 1920’s”.

Don’t get me wrong – historic plant community composition can be helpful.  It’s nice to know how things have changed because it helps us understand why, or at least helps us ask the right questions.  Answers to those questions can guide us as we devise management strategies.  Where we get into trouble is when we use past conditions as explicit targets for today’s stewardship. 

Our prairies live in a different world than prairies of old.  Habitat fragmentation, rising atmospheric CO2 rates and nitrogen deposition, climate change, and invasive species are just some of the major factors that have changed within last century or two.  We should expect prairies to adapt to those drastic changes.  After all, adaptation is one of their best features!  

Invasive species such as crown vetch (Securigera varia) and many others have drastically changed the competitive environment within prairie plant communities.

History goggles also come into play when we think about prairie management tools and tactics.  How many discussions have you been in that center on the historic frequency and/or season of fire in prairies?  As with plant composition, understanding when and how fires burned in the past can be helpful, but yesterday’s fire frequency shouldn’t automatically be today’s fire frequency.  See above for some of the major differences between historic and present-day prairies.

People who apply grazing to grasslands often wear very thick history goggles.  If I had a nickel for every time someone’s tell me their particular grazing strategy mimics what bison used to do, I’d be swimming in nickels.  I don’t want to swim in nickels.  Even if your approach somehow perfectly mirrors what bison used to do (and it doesn’t), why would that be the best approach for today’s prairies, which aren’t what they used to be?  That applies, by the way, to whatever grazing animal you’re working with – including bison. 

There are lots of great reasons to put bison in prairies, cultural, ecological, and otherwise.  Expecting them to eradicate smooth brome and reverse climate change, though, is going to lead to some big disappointment.  That doesn’t mean bison (or cattle, for that matter) can’t play important roles in today’s prairies.  In many grasslands, especially larger ones, they can manipulate habitat structure, combat the dominance of grasses, and create lots of wonderful messiness.  They can’t (or won’t), however, turn back the clock. 

Bison or other large grazers can play important roles in some prairies, but they can’t suppress rising atmospheric carbon dioxide.

We’ve got to cast off our history goggles and look forward if prairie conservation is going to succeed.  Restoration and management strategies need to be built on creating future prairies, not past ones.  That’s an uncomfortable, even scary, prospect though, isn’t it?  We don’t have any reference points in the future, after all.  It’s easier to look back (or guess) at what used to be and try to aim there.

I don’t have the answers to this dilemma.  I do have ideas.

Prairie communities really are good at adaptation.  Because of that, I think we should be looking for ways to facilitate and guide prairies as they adjust to new conditions.  One way to do that is to help them maintain the resilience they need to adapt.  We do know something about how to do that.  (Remember, ecological resilience doesn’t mean natural communities don’t change.  Instead, it’s a measure of their capacity to adapt.) 

The ecological resilience of prairies relies heavily on two factors: habitat size/connectivity and biological diversity.  The first helps the second persist and the second provides the redundancy of function that means there are species to fill crucial roles no matter what’s a prairie has thrown at it.  Making prairies bigger and better connected comes through restoration (reconstruction) efforts that build new grassland habitat adjacent to and between existing habitats.  We have lots of evidence that prairie species respond well to that kind of restoration.

There are lots of thoughts about how to manage for biological diversity in prairies, many of which seem to work well.  There isn’t a single best way to do it, and the effectiveness of practices and approaches can vary by geography, soil type, prairie size, and many other factors.  The key is to focus on the diversity of the plant community, as well as the more difficult to measure communities of animals, fungi, bacteria, and others. 

The diversity of plant and animal communities (and other taxonomic groups) is a key to the ability of prairie communities to adapt to change.

This is where I think it’s most important to push past our reliance on history.  It’s tempting to judge plant species, for example, by whether we think they used to be part of the plant community at a particular site, or how abundant they might have been.  We’re getting to the point where that may not be very relevant anymore.  That includes non-native plants, by the way. 

Now we’re getting into really uncomfortable territory for some folks but let me be clear that I’m not proposing we stop preventing the appearance or spread of all non-native plants in prairies.  What I am proposing, however, is that the native or non-native status of plants might not be the best metric to apply.  Many of us have already started down this path by looking at natives like Canada goldenrod, for example, as a species that can be problematic if it’s allowed to run rampant.  Why do we care?  Because in some places, it can become dominant enough that it suppresses the diversity of the plant community.  That’s a bad thing for ecological resilience.

Non-native plants that have the same potential to suppress diversity need to be targets for management action.  However, some non-native plants don’t suppress the diversity around them – they add to it.  I think that’s ok.  The immigration of new species into prairie communities is inevitable, so fighting it seems fruitless. 

Yellow salsify, aka goat’s beard (Tragopogon dubius) is an example of a non-native plant that seems to have joined plant communities I’m familiar with in an innocuous, if not helpful, way.

In many places, woody plants – native and non-native – are becoming more abundant in prairies.  Their success is driven largely by rising CO2 levels, which prairie managers have no control over.  That means that in some cases, we’re just going to have to figure out how to manage for biodiversity in shrubby prairies.  We don’t know enough about how to do that yet.  Instead of pouring all our limited resources into resistance, we’d be smart to start learning about how to manage the height and density of shrubs and see how plant and other communities respond.

I could go on, but I think the key point is that focusing on ecological resilience, and thus biological diversity, gives us a target to aim for as we look forward.  We can evaluate the success of our management strategies by whether they lead to increased or decreased plant and animal diversity.  If our prairies are maintaining their diversity, they should have a good chance at adapting to whatever is thrown at them. 

It’s hard to turn away from history as our reference point for success.  You know what else is hard?  Failure.  It’s frustrating to try and try to restrain prairies from moving away from what they used to be.  Why are we subjecting ourselves to that frustration?  Let’s see if we can learn how to support our favorite ecological communities as they flex their adaptation muscles and find ways to thrive in this new world.