The Prairie Ecologist

This is a post written by Jasmine Cutter, one of our 2014-15 Hubbard Fellows. All photos are by Jasmine.

Howdy, Prairie Ecologist friends!
I remember how much I looked forward to the Fellows’ posts before coming to the Platte River Prairies, so I apologize for the glacial pace of my updates. A considerable amount of my time and brainspace over the last two months has been occupied by small mammals (or s’mammals, as I prefer to call them). There are definite challenges to undertaking a project during the growing season (namely balancing project time and stewardship time), and throughout the process of the project and the summer there have been some unexpected surprises (mostly good), and a lot, a lot of learning.

Mike Schrad, Nebraska Master Naturalist and my small mammal project mentor.

Mike Schrad (left), Nebraska Master Naturalist and my small mammal project mentor.

In the briefest of terms, I’ve been tromping through our Derr sandhills (a unit which includes both restored and remnant prairie on the edge of the Platte River Valley), battling cows, thunderstorms, and a lack of sleep in the pursuit of learning more about the small mammal community in this unit. I was initially drawn to this site because the Derr sandhills contain pocket mice (Perognathus flavescens) and Northern grasshopper mice (Onychomys leucogaster). The pocket mice are minute, streamline and silky, whereas the grasshopper mice are beefy and aggressive (and probably also soft, but getting your finger near enough to find out is tricky), yet, despite their differences, they’re both endemic to sandy soils. As these critters are relatively unusual, my study will give us a chance to learn more about their habitat preferences, and hopefully enable us to manage the site in a way that ensures the continuation of healthy populations. Although these two species have remained the most endearing through out my study, my affection has also expanded to include shrews (they have venomous saliva and black-tipped teeth!), voles (ferocious teddy bears) and harvest mice (very agile and keep a neat nest). Deer mice tend to have a heavy parasite load and botfly sores (not to mention the possibility of hantavirus and carrying lyme disease), and therefore are often pretty icky. At this point, I am done with trapping for the most part. Soon, I will be collecting vegetation and site data for each trap site (that’s ~370 sampling points!), and this winter, I will be seeing if there are any relationships between the presence of certain species and site characteristics.

Beefy lil grasshopper mouse, so-called due to their carnivorous diet. At night, they sing to defend their territories.

Pocket mouse. The clip on its tail is what is attached to the scale used to weigh them. While it is undoubtedly a little uncomfortable, there is no permanent damage. The clip is also a helpful way to hold onto animals so I can take a photo. It’s essential to my study that I am able to document how the pelage (fur) color varies between individuals.

Scary shrew teeth. Unlike the rest of the similarly-sized critters I caught, shrews are not rodents. They are in the order Soricomorpha. They are mostly carnivorous and have saliva that paralyzes their prey.

There have been a few surprises during this project. For example, I have discovered that cows don’t like science. They have eaten my flags, licked my traps several feet off my transect, and squashed a few for good measure. If only their curiosity could be used more constructively!

One of the best surprises was opening one of my traps and finding a least weasel inside! I was waaayyy more intimidated by this critter than it was by me. Despite its ferocity, it was impressively lightweight. This littlest weasel was longer than the thirteen-lined ground squirrels that I also caught that day, but considerably lighter. The ground squirrels maxed out my 100 gram scale, whereas the weasel was only 70 grams! The weasel was also impressively smelly, living up to the family name of mustelidae. I was a little worried that no other small mammals would go into that trap the next night because it smelled of predator, even after I sprayed it with Lysol. However, the harvest mouse I caught the next night was undeterred. No wonder s’mammals have such a short lifespan. Another surprising find on a different transect was an embarrassed-looking leopard frog. My bait seems to attract a lot of crickets, so I imagine that’s what lured the frog. And the cutest capture was these two baby voles that managed to wander into one trap.

Thirteen-lined ground squirrel (Ictidomys tridecemlineatus). When I open a trap, I gently plop the critter into a bag in order to minimize handling exposure. I can weigh, identify and sex the critter while it’s in the bag. It’s safer for me, and the animal is only in there for a few seconds to a minute.

Weasel tryptic. Although none of these manage to capture the full length of the weasel (Mustela nivalis), they do manage to capture what you’d be likely to see – a reddish blur.

Baby voles!

In addition to the excitement of peeking into every closed trap, there have been other perks to the project. I’ve gotten to see way more sunrises and sunsets than I would have otherwise. I love the freshness of the mornings, how the grass glows orange, and the spiderwebs glisten, and how much my mood (and finger mobility) improves once the sun crests the sandhills. I’ve gotten to hear the weird robotic chirpings of the swallows at sunset. The light at these times is able to make pretty much any photo look amazing, so it’s a little less discouraging to compare some of my photos to Chris’. I have also really enjoyed the slower pace of sampling, of covering my transect by foot. I spend a lot of time in the prairies, but infrequently do I have time to slow down and appreciate how the prairie community changes meter by meter. I have gotten to know my transects well, and I look forward to seeing if/how the patterns I’ve noticed play out in the data.

I’ve taken thinking like a s’mammal maybe a little too much to heart. Whenever we visit a new prairie, I think, ‘this looks like good pocket mouse habitat, I wonder if they have any? I wish I had my traps…’. I am also really grateful that so many mammalogists have been willing to donate their time and resources. I’ve learned a lot about species identification from them, and it’s exciting to make new connections with other institutions.

Sunrise!

My pile of science. Traps generously lent out by Montana State University and Kansas State.

Pocket mouse pockets. They store seeds in there to bring back to their nest cache.

Pocket mouse pockets. They use external fur-lined cheek pouches to store seeds until they can bring them back to their nest cache.

This is not to say that this project has not had its challenges. I would say the main struggles have been setting reasonable goals (never a strong suit), keeping track of all the moving pieces (Do I have all my equipment? Am I recording all the right info? When do these traps need to be mailed back to Montana?), not losing things (Luckily the two mice than ran off with my scale clips were recaptured the next day!), and figuring out how to do the majority of the sampling by myself. It has been a long, time-intensive process for just five sampling transects. And, the project has not been without its dangers. The most dangerous part of the study has definitely been cacti. You wouldn’t believe the number of cacti I’ve accidentally kneeled on, or kicked into myself! I don’t recommend it. But, when these aspects of fieldwork start to get me down, I remind myself that I caught a weasel, and that’s pretty freaking cool.

When I was at the Niobrara Valley Preserve a couple weeks ago, I spent some time exploring the area north of the river where the 2012 wildfire ripped through oak savanna and ponderosa pine woodland. As discussed in earlier posts, the density of trees, especially eastern redcedar, fueled a fire that killed nearly every pine and cedar in the 3000 acres of Preserve land on the north side of the river. Most oaks and other decidous trees were topkilled, but many resprouted within a few weeks of the fire. I have been following the regrowth and recovery of this part of the Preserve with great interest, and trying to help the Preserve staff as they think about how to manage the area in the future.

Here is a series of photos from an uphill hike I took on September 18. The photos are roughly in order of elevation, starting at the river road (just above the floodplain) and proceeding upslope to the ridgetop at the north edge of the valley.

On the first slopes above the river road, hemp (Cannabis) and marestail (Conyza) dominate the understory of a woodland that now consists mainly of skeletons of eastern redcedar and oak trees. Most of the oaks have resprouts from their bases, however, and a few still have live branches up high.

The abundance of marestail (a native pioneering species) is especially interesting to me because it’s the same species that usually dominates two-year-old prairie plantings. This is the role it plays in ecosystems, and it plays it well. It’s difficult to see very much below the marestail, but when I looked closely, I found scattered grasses, sedges, and wildflowers – a good sign of future recovery.

As I walked higher and got into the prairie-covered slopes, ragweed (Ambrosia) replaced marestail as the visually dominant plant in the formerly shaded areas beneath cedar trees. The ragweed is playing the same role as the marestail – quickly filling in the open space until a more permanent plant community establishes. That community should move in pretty quickly in cases like that shown in this photo, in which a cedar tree is surrounded by prairie.

Higher up the slope, large areas of prairie had not been encroached upon by cedars, and recovery after the fire was just as predicted – quick and easy. The vegetation was still a little thin, but that was more of an aftereffect of the 2012 drought than of the fire. In this image you can see the scattered cedars further downslope (such as the one featured in the previous photo).

Almost every bur oak tree I saw was vigorously resprouting from the base. Those numerous stems should thin themselves down to three or four major trunks over the next decade or so. Some of the branches were already 6-8 feet high, so recovery is proceeding quickly. These oaks were growing along the edge of one of many steep draws scattered along the north side of the river. As I was wading through 3-4 foot tall marestail, I couldn’t help but wonder if that dense growth and the presence of mountain lions in the area explained the near absence of deer browsing on the oak sprouts (Ecology of Fear). I don’t know if the deer felt it, but I sure had moments of discomfort, knowing that if a lion was hiding in the weeds nearby, the steep slopes and thick vegetation would make escape nearly impossible. It made my hike a little more exciting, but I didn’t stay down in those draws very long…

I was surprised and pleased to see numerous examples of large sedge patches growing under the marestail forest, especially on the steeper portions of draws. I don’t remember seeing many sedges last year, so either I missed them or they are expanding rapidly. Either way, they will sure help stabilize those slopes as other plants move in to join them, and they’ll also help carry fire when we restart fire management of the area.

High on the slopes, where ponderosa pine and eastern redcedar had dominated just a few years ago, the scenery was every bit as spectacular as it had been before the fire – just different. Marestail was abundant here too, but there was quite a bit of grass and wildflower cover as well, and several shrub species were flourishing, including smooth and skunkbush sumac, chokecherry, snowberry and others. Despite the density of scorched tree trunks, the overall feel of the slopes was not one of death and destruction, but rather of abundant life.

Even the very steep erodible slopes at the very edge of the ridge top were full of previously established perennial wildflowers and shrubs, as well as colonizing annuals.

I came down the slope after my walk with a great feeling of optimism. My greatest worries about this area of the preserve had been that

1) Invasive plants would fill the slopes before the native vegetation could recover, and we’d be faced with the difficult challenge of attacking those invasives in difficult terrain.

2) Numerous eastern redcedar trees would colonize the slopes before there was enough vegetation to carry prescribed fires to knock those cedars back.

3) Soil erosion would be so severe that the seed bank needed to reestablish the native plant community would wash down the slope, along with the topsoil those plants needed to grow.

None of those three have occurred – or at least to the extent I feared they might. There has been some erosion, but much less than I anticipated, and it doesn’t seem to be affecting vegetation recovery much. I haven’t seen any truly invasive plants yet – which doesn’t mean they aren’t there, but they sure aren’t roaring in. Finally, the recovery of the vegetation has been fast enough that we should be able to start running prescribed fires up the slopes within the next few years. I didn’t see any little cedar trees on my walk, and while I’m sure there are a few around, the abundance is much less than I feared, and our ability to use prescribed fire should make it fairly easy to control them, except on the steepest slopes.

Most of all, the beauty of the Niobrara Valley has survived the wildfire. The pines are gone from some parts of the valley, but are still doing well in other areas nearby, including other parts of the Niobrara Valley Preserve. Whether or not (or when) they’ll return to the site of the 2012 fire is still an open question. Regardless, there is abundant life on the slopes north of the river. Just because those slopes will be dominated by different species than before doesn’t change the scenic or ecological value of the site. It’s still one of my favorite places on earth.

The Prairie Ecologist

Essays, photos, and discussion about prairie ecology, restoration, and management

Hubbard Fellowship Post – S’Mammals with Jasmine

Continuing Wildfire Recovery at the Niobrara Valley Preserve