Photos of the Week – March 16, 2024

I spent some time at the Niobrara Valley Preserve this week. Apart from some other work duties, I was curious to see how far spring had progressed and check on the results of a prescribed fire we conducted last November. The executive summary is this: spring isn’t quite here yet and the results of the fire look great so far.

This middle-aged bull took a quick break from grazing long enough to check me out.

I know it’s only mid-March, which is pretty early to expect much green-up, let alone flowering of plants in northern Nebraska. On the other hand, it’s been a mild winter, especially during much of February and March. I’ve been seeing photos of blooming pasqueflower on social media and have been finding more and more insects as I walk around. I figured there might be a chance of finding an early pasqueflower in bloom at NVP.

Not quite yet.

However, there was still plenty to see. I spent time with a small group of bison and watched them graze on the dormant vegetation from last season. Even after seeing this for many years, it still astounds me that these huge animals can fulfill their nutritional needs from dried-up plants. They’ve had millennia to hone their methods, of course, but still. Those are big animals and I don’t know if you’ve ever chewed on dried up grass but it doesn’t seem very satisfying.

The bison were very focused on grazing and paid little attention to me as they slowly foraged their way past my truck.
Heads down and focused.

Those bison are picking up some green(ish) sedges too, of course, which are valuable because they green up early and stay green late into the fall and early winter. Even so, the bulk of what the bison were eating this week was not green.

You might be thinking – well, wait, hay is just dried vegetation too, right? That’s supposed to be nutritious.

The thing with hay is that it’s harvested during the growing season when the leaves and stems are green and full of nutrients. Plants tend to lose nutritional quality as they mature, and that’s especially true by the time autumn forces full dormancy. Some plants reserve more nutrients in their aboveground portions than others, but they’re still not what they were in the summer.

Haying equipment cuts the tops off plants while they still have their full complement of nutrients and those nutrients remain as the vegetation dries out and gets baled or stacked up for later. The plants these bison are eating had completed their annual cycle of growth and dormancy, so the nutrient content was significantly different.

This one took a quick break to pose but got back to grazing almost immediately.

While I was in the area, I checked quickly on the little prairie dog town closest to headquarters to see what the activity level was like. It wasn’t frenetic, but there were a few running around. One of them was willing to stare at me long enough for me to get a photo before it dove underground. I didn’t linger, and let them get back to whatever they were doing.

Several prairie dogs were scurrying around. This one stared at me for a while before it dove into its hole.

When I stopped by my favorite hotspot for pasqueflowers, it took me a while to find any of them. The patch grows on a steep north-facing slope and I wandered up and down that slope for several minutes before I spotted the first fuzzy bud. It helped that I was looking back toward the sun, which backlit the tiny hairs and made each bud look like a tiny lightbulb. No flowers yet, but it won’t be long!

The pasqueflowers weren’t blooming yet, but they were getting close.

I didn’t see any flowers, per se, on the whole trip. However, I did find flower-like structures on a couple different species. There were at least a couple different mosses with sporophytes (fruiting bodies) growing in shady spots, both at the edge of the prairie/woodland border and down along a creek. In addition, some of the lichens in the woods were showing off their vase-like perithecia (I had to look that one up).

Moss sporophytes on a steep sandy bank near the edge of a woodland.
Moss sporophytes found along a creek in a woodland.
Lichen fruiting bodies (perithecia) in a woodland habitat.
This wolf spider was scurrying around in the leaf litter upslope from a creek.

Little invertebrates were starting to move around, too. I saw flies, lacewings, and lots of grasshoppers – especially in bare ground on sunny south-facing slopes. I played for a while with a little wolf spider in the woods who was surprisingly willing to put up with me. When it started running off, I just put my hand down in front of it and it turned around and climbed back up on a leaf for more photos. That’s not usually the way that works out, but I was sure grateful.

This plains sunflower (Helianthus petiolaris) skeleton has been scratching a pattern in the sand.

One of my priorities for the trip was to spend some time checking out the results of last year’s late November burn in the bluffs north of the river. The 2012 wildfire had taken out most of the big ponderosa pines and eastern redcedars and forced many of the bur oaks to resprout from their bases. Since then, smooth sumac had spread significantly and little eastern redcedar trees were popping up all over. We needed a fire to kill those little cedars and help us (temporarily) set back the sumac a little – in conjunction with some other treatments we’ll be trying.

Last fall’s 900 acre burn didn’t burn completely (by design). Some entire draws escaped the fire, but a lot of smaller patches didn’t burn because they were on steep rocky slopes where there wasn’t enough grass to carry fire well.
This cricket was moving around in last fall’s burn. There were lots of band-winged grasshoppers, too, but none of them wanted to hang out with a photographer.

I was most curious to learn the fate of some little ponderosa pines that had been planted near the top of the ridge after the wildfire. At the time they were planted, I was skeptical that they’d survive. I figured they’d either fail to establish roots or would be taken out by the first prescribed fire we ran up that slope. After all, they’re not known to be good about surviving fires when they’re little.

Small ponderosa pines experienced mixed mortality near the top of the steep ridge. The one in the foreground looks like it’ll survive because fire intensity was low as the flames crept downslope from the top. If you look closely, you can see one that didn’t make it right in the middle of the frame.

I was pleasantly surprised by what I saw. There were definitely some toasted pines up there, but I’d say 80% of the trees I found were alive – either untouched by fire or only lightly scorched. The ignition pattern of the fire probably helped a lot. We’d lit along the top and let the fire work down the hill, which kept the heat low and flame lengths short. In fact, the fire didn’t burn very far downslope in many places because the density of grass wasn’t enough to offset the fact that the fire had to burn downhill (heat rises, so fires burn much better going uphill than down).

Later in the burn, fires lit down below raced upslope for a while, but most ran into enough bare rocky areas on the ridges that the flames never reached the top where the pines were. As a result of all that, we have quite a few little pines that still have a chance to become part of a future pine savanna up there. In fact, we’ve got way more than we really need, since we don’t want very high tree density. We’ll deal with that later if we have to. Those little guys still have a lot of living to do before they’re savanna-sized.

We killed thousands of these little eastern redcedar trees in last fall’s fire, which was one of the primary objectives.

We sure did kill a lot of eastern redcedars in the fire. I knew there were quite a few moving in, but I was still surprised by the number of orange (and dead) trees scattered around. Many of them were on the lower slopes, where the fire burned really well, but we got some up higher on steep slopes too. There will be a few the staff will have to chase down with chainsaws at some point, but I was really pleased by how well the fire did the work for us.

The smooth sumac will pop right back this spring, but the fire at least took out all the aboveground buds and that’ll stress the plants a little. We’re talking now about what we can do to build upon that stress and slow the recovery of the sumac clones long enough to let the prairie community beneath the shrubs survive. That’ll be part of a continuing set of trials we’ve been setting up to learn more about how to suppress sumac and other shrubs in this kind of topography and at this scale. Stay tuned!

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.