By Jenn Simons
Nachusa Grasslands Science Extern
On January 10th, 2019 I made a simple phone call to Nachusa Grasslands. Four months later, I was packing up my things to spend the summer living 480 miles east of my hometown. And with that, this Nebraska native ended up in an eastern tallgrass prairie state of both mind and place.
Prior to that fateful January day, as a graduate student at the University of Wisconsin-Madison I had narrowed down my research interests to the impact of conservation grazing on vegetation in midwestern prairies. My goal was to meet the requirements of my degree with a research project at the intersection of stewardship and applied ecology. Though the importance of disturbance to prairie management is well known, grazing on restored and remnant prairies has been a contested issue. Additional data to understand some of the trade-offs to using grazing for land management facilitate better understanding and application of the tools available in a land manager’s toolbox. The only thing that I was missing to begin my research was access to a herd of conservation grazers (nothing too significant, right?).
During my quest to connect with folks using grazing as a land management tool in prairies, I ended up on the phone with Dr. Elizabeth Bach at Nachusa. As many of you know, it’s hard not to fall in love with a site as beautiful and biodiverse as Nachusa Grasslands. It’s even harder not to fall in love if that site also features a herd of grazing animals and the existing infrastructure to study their impacts. After my first conversation with Dr. Bach, I was sold. Nachusa was where I wanted to be, and the impact of their bison was what I wanted to study.
In my case, and the case of many other grad students, there’s a gap in available funding between spring and fall school semesters. Grants and assistantships don’t always pan out, and many degrees in ecology require a large amount of data collection during the summer months (something rather at odds with working full time). Fortunately, 2019 marked the first summer for a Science Extern position at Nachusa. Open to all graduate students currently or beginning to conduct research specifically at Nachusa, the externship was to be awarded as an external grant to the student’s home university and paid as a salary, allowing the student to remain enrolled and continue receiving benefits. Just as the crew of seasonal employees spends their week supporting land stewardship needs throughout the summer, the role of the science extern was to support data stewardship needs throughout the summer. This position continues Nachusa’s history of encouraging research and providing opportunities for budding conservationists.
With my fingers crossed, I submitted my application for the position and tried not to get my hopes up. I made a mental plan B (and C and D) for how I might be able to make my Nachusa research dreams come true if my application wasn’t successful. Work full time and collect data on the weekends? Take out loans? Choose a simpler research question? These are questions most grad students have had to seriously consider at some point. When sites like Nachusa are able to offer summer positions that merge science with practice, both the student and the site benefit from the results.
Much to my delight, plan A came through, and I never looked back. Since May I’ve been assisting in collection, entry, and analysis of core ecological data for Nachusa while simultaneously collecting my own data. To answer my research questions, I’m leveraging twenty-two fenced plots (10mx18m) replicated across habitat types in the 1,500 acres of bison habitat that were designed and built by Bill Kleiman, Cody Considine, TNC staff, and collaborating scientists prior to the introduction of the bison in 2014. As opposed to keeping something inside a fenced in area, these fenced plots function as “exclosures” and keep bison outside the fenced area. Building on plant community data taken in 2014-15 and 2017-18, I’m collecting additional data to compare changes in the vegetation diversity, structure, and abundance along with soil compaction between grazed and ungrazed land over time. With the mentorship of Dr. Bach and my advisor, John Harrington, these data will be analyzed and contribute to both the advancement of my degree and the understanding of how bison have impacted Nachusa’s vegetation.
In addition to the various science program tasks, opportunities abound to participate in stewardship activities and learn more about careers in ecology outside of academia. I’ve gotten to track Blanding’s turtle, set traps for small mammals, participate in evening moth surveys, observe rare plants in their natural settings, improve my R coding ability, utilize ArcGIS to create new maps, collect seeds and control weeds with the seasonal crew, and talk with highly knowledgeable volunteer land stewards. I can honestly say there’s no place I’d rather be this summer than at Nachusa Grasslands, and I’ve already become a better ecologist as a result.
By Leah Kleiman
Amur honeysuckle (Lonicera maackii) is a perennial shrub native to temperate Asia and is invasive in the Midwestern United States. It now infests many savannas and woodlands and is difficult to eradicate.
Bill and Susan Kleiman and I are co-authors of a study recently published in the journal Ecological Restoration, titled “The Successful Control of Lonicera maackii (Amur honeysuckle) with Basal Bark Herbicide” (http://er.uwpress.org/content/36/4/267.full.pdf+html). Our study looked at the efficacy of basal bark application, where a mineral oil solution of herbicide is sprayed in a 6-inch band on the bark without cutting the plant. Our study found 100% mortality with basal bark treatment.
A variety of other treatment methods are used to battle honeysuckle. Manual pulling works well on small individuals in soft ground, but becomes impossible with larger sizes. Cutting and treating the stumps with herbicide is effective, but very time-consuming. We recommend the cut-and-treat method for sensitive high-quality areas. A foliar spray of herbicide is effective and efficient, but will have much more off-target damage and can only be used in the growing season. Fire is a useful tool in keeping brush at bay, but it will only top-kill shrubs. The basal bark method is efficient, effective in all seasons, and has minimal off-target damage.
Some things to keep in mind: 1) Re-treating is important for success. One treatment is not enough. Some shrubs will inevitably be missed, and yearly recruitment will occur until the seedbank is exhausted. 2) Honeysuckle treated in the dormant season may still leaf out and die later in the growing season. So if you notice this, it does not mean that your treatment has failed, but rather that you need to check back at a later date (typically late summer/fall).
Our study concludes that basal bark treatment paired with regular fire is the optimal way to eradicate honeysuckle invasions. For more information on treating honeysuckle with basal bark, see the February 3, 2019 blog post “A Study on Controlling Amur Honeysuckle (Lonicera maackii)” by Kaleb Baker.
By Kaleb Baker
Amur honeysuckle (Lonicera maackii) is an invasive shrub that flourishes along forest edges and in open woodlands such as those at Nachusa Grasslands. Amur honeysuckle shades out native flora with its early leaf-out and prolonged leaf retention, and when left uncontrolled, can produce a near monoculture, threatening biodiversity.
Land stewards everywhere have implemented a variety of different eradication methods, including hand pulling, cut-and-treat with herbicide, foliar-applied herbicide from backpacks or helicopters, basal bark herbicide treatments, and prescribed fire. Continuous treatments and monitoring are needed to eradicate Amur honeysuckle, making the cost, effort, and time requirements of controls important.
Knowing the efforts we go through to manage honeysuckle, as well as the amount of conjecture surrounding the best practices, I worked with my advisor Dr. Nick Barber to study how effective basal bark treatments and prescribed fire are at controlling honeysuckle., I decided to study how effective basal bark treatments and prescribed fire are at controlling honeysuckle. Basal bark and fire are regularly-used control methods at Nachusa. Basal bark treatments involved spraying a 20% solution of triclopyr herbicide around each plant’s base from a backpack, which was both quick and easy. In this study I included 800 individually-marked Amur honeysuckle at 5 different sites within Nachusa Grasslands and Franklin Creek State Natural Area. Basal bark treatments were applied in fall 2017, winter 2018, early spring 2018, and late spring 2018 to see if the season of application affected the mortality of honeysuckle or the extent of damage to non-target flora. Prescribed fire was administered to half of each of the 5 sites in spring 2018. I then checked mortality in the early fall of 2018 to allow the honeysuckle time to either drop its leaves and regrow them (falsely dead) or to retain its leaves for an extended period of time before dying (falsely alive).
I found that basal bark applications were equally effective at killing Amur honeysuckle, regardless of treatment timing. The combined mortality rate of herbicide treatments was 98.4% across all herbicide treatment seasons, compared to a 2.5% mortality with no basal bark treatment. Prescribed fire did not impact mortality positively or negatively.
I also placed a 1m2 quadrat around 200 Amur honeysuckle to measure off-target damage to the plant community in spring 2018, finding a decrease of living cover equating to about a 10-inch radius. The off-target “ring of death” did not differ based on fire treatment or basal bark season.
I was lucky to receive a grant from the Friends of Nachusa Grasslands where I will be able to return in May 2019 to resample the off-target vegetation quadrats to evaluate how quickly the flora recover from the various treatments.
From my current results, I highly recommend using basal bark treatments to control Amur honeysuckle for all but the highest quality of areas. The speed and ease of use allow managers to cover large swaths of invaded areas across fall, winter, and spring seasons. The standing dead material from the honeysuckle can be reduced with a masticator or brush mower in the non-growing season or with regular prescribed fire, which should be implemented anyway.
Kaleb Baker is a Master's Candidate at Northern Illinois University, focused on natural areas management practices, and current Stewardship Committee Chair for Franklin Creek Conservation Association.
By Dr. Elizabeth Bach, Ecosystem Restoration Scientist
December 5 is World Soil Day, a time to recognize the vital role soils play in our ecosystems and health: growing food, filtering water, recycling air, mitigating climate change, and supporting more than 25% of all biodiversity! Soil is the foundation of prairie restoration at Nachusa Grasslands, the starting point of a prairie planting. There are many questions about how soils impact prairie restoration success and how prairie restoration affects soils. Today, we highlight a few of the soil-focused scientific studies that have been conducted at Nachusa Grasslands:
Question: Do communities of soil critters like earthworms, ants, ground beetles, centipedes, millipedes, and spiders change during prairie restoration?
Prairie restoration increases the number, abundance, and mass of soil critters like earthworms, ants, centipedes, and spiders with time since planting. Interestingly, different prairie remnants, even within the Nachusa preserve, have very different communities of soil invertebrates, and it’s difficult to know what a typical remnant invertebrate community may look like.
Wodika & Baer 2015. If we build it, will they colonize? A test of the field of dreams paradigm with soil macroinvertebrate communities. Applied Soil Ecology 91:80-89
Wodika et al. 2014. Colonization and recovery of invertebrate ecosystem engineers during prairie restoration. Restoration Ecology 22: 456-464
Ground beetles show a different pattern, with high numbers of species and abundance in young plantings. Although older plantings had lower species richness, the roles those species play in the ecosystem diverged, indicating that older plantings support stable, diverse beetle communities that fill multiple roles in the ecosystem (e.g. different sizes, active at different parts of the day/night, eating different things).
Barber et al. 2017. Species and functional trait re-assembly of ground beetle communities in restored grasslands. Biodiversity and Conservation 26:3481-3498
Question: Do soil microbial communities change during prairie restoration?
Older restorations at Nachusa host microbial communities that are distinct from younger plantings, and that more closely resemble remnant communities. A couple of the key bacterial groups distinctive of prairie remnants and older restorations are Verrucomicrobia and Acidobacteria. The next question is to learn more about what those bacteria do!
Barber et al. 2017. Soil microbial community composition in tallgrass prairie restorations converge with remnants across a 27-year chronosequence. Environmental Microbiology 19: 3118-3131
Question: How does plant diversity impact ecosystem functions like soil carbon and nitrogen cycling?
Nachusa’s high plant diversity restorations had more roots, more microbial mass (especially mycorrhizal fungi), more structured soil, and less “leaky” nitrogen compounds that can wind up in water ways compared with low plant diversity restorations in the same area. This is the first study to show that very high plant diversity restoration can lead to improved ecosystem functioning.
Klopf et al. 2017. Restoration and management for plant diversity enhances the rate of belowground ecosystem recovery. Ecological Applications 27:355-362
By Ryan Blackburn
In the spring of 2013, I had little to no knowledge of tallgrass prairies or the various forms of life they held. I was an undergraduate at the time, and my class at Northern Illinois University had an opportunity to visit Nachusa Grasslands and receive a tour given by one of their dedicated stewards, Jay Stacy. As the class looked out across the beauty rolling over the tallgrass landscape, Jay directed our view downwards at our feet and started naming twenty or more plant species in just a little patch of dirt the size of a laptop. Jay also spoke of the rumors that bison may be coming to the landscape and how they were thought to have the ability to increase diversity of the prairie plant communities which already seemed teeming with life. This was the moment I realized that the tallgrass prairie and plant communities they held were something that I wanted to know more about. After a couple of growing seasons, a reintroduction of bison onto the landscape was accomplished, and my masters research was born.
Bison are large animals that require a lot of energy, which mainly comes from one family of plants, the grasses (Poaceae). Due to this selective grazing, bison create open space in their habitats for wildflowers to take root and increase the diversity of the tallgrass prairie overall. At least this is a summary of what had been observed in the research of remnant (never-plowed) prairies west of the Mississippi River which reintroduced bison as well. In hopes to recreate this tale of romance between bison and tallgrass prairies, Nachusa Grasslands reintroduced bison to their preserve of both remnant and restored lands. The question still remained: will their diet in this new area largely be made up of grasses, and how soon would we see changes in the plant communities following their reintroduction? To study this, I looked at both bison diet and differences of plant communities between sites with and without bison over a period of two years.
To figure out what the bison were eating, I used a technique called stable isotope analysis on bison tail hair pulled during the annual roundup. This allowed me to find signatures of plants within the bison hair and estimate these plants' abundance within bison diet. Better yet, I could cut bison hair into segments and look for seasonal changes. Through this analysis I was able to estimate major dietary groups of their diet between May 2016 and September 2016. I found that bison were doing what Nachusa brought them here to do: eat grasses (for the most part)! However, in late summer bison started to transition from largely grass species to wetland species and some wildflowers, something that had never been documented before. This was an unexpected shift that may lead to unforeseen consequences to wetlands, but further research is needed to speak to this.
Now that we know bison are mostly eating grasses during the growing season, we want to know how this might be impacting prairie plant communities. Attempting to answer this question, I, along with a team of dedicated plant enthusiasts, counted and measured percent cover of plant species across sites with and without bison. I quantified these communities in a variety of ways and compared them to see if bison were driving any differences between the two communities. Even though the bison had only been at Nachusa for three years, there were already evident changes happening within the plant communities. As predicted, areas with bison had more variation within their plant communities and had a higher ratio of native to non-native plants than those sites without bison. Further analysis shows that both variation and native to non-native ratios may be driven by bison preference of certain species such as bluegrasses (Poa compressa and Poa pretensis) suggested by a higher occurrence of these species in sites without bison.
The bison of Nachusa Grasslands were reintroduced to do a job: increase the diversity of plant communities. Though my research does not yet see an increase in diversity, it does suggest that bison are starting to go to work eating grasses and changing plant communities around them. Continued monitoring of these communities (especially those tasty wetland communities) is needed to gain a better understanding of bison impacts and how they progress in restored tallgrass prairies.
Ryan Blackburn just received his M.S. degree studying bison diet and their role in the restoration of plant communities in tallgrass prairies. Ryan is also looking at grazing impacts on a landscape scale using drone aerial imagery. In 2016, he received a $1,500 Friends of Nachusa Grasslands Scientific Research Grant for his "Determining Bison Diet and Bison Effects on Vegetation in a Chronosequence of Restored Prairie at Nachusa" project.
By Heather Herakovich, MS
Birds are known harbingers of spring. Although most stick around during the brutally cold Illinois winter, we don’t take much notice until they are everywhere in our yard, waking us up in the morning and pooping on our cars: spring time!
It’s finally springtime, and at Nachusa the birds are singing, vying for territory, and finding mates. These aren’t your typical backyard birds like the American robin and northern cardinal, who are your usual early morning alarm and repeating snooze. Nachusa holds a wide variety of bird species, including some of the ones in the most need of conservation: grassland birds. They come with funny names like bobolink and dickcissel, and in all shades of brown and yellow and sometimes black.
Grassland (prairie) birds are declining at a faster rate than most bird species, and a majority of this has been caused by habitat loss. Illinois is the prairie state, but only one hundredth of its original prairie remains. Places like Nachusa are doing their best to restore the agriculture fields and recreate the best prairie as humanly possible. Doing this requires a lot of hard work, hours of picking seed, planting seed, removing unwanted plants, burning portions of the prairie and mowing. The birds seem to be responding to this management fairly well. However, there is an elephant in the room, or shall I say a bison in the prairie.
American bison are our national mammal, and rightfully so. These large herbivores used to roam most of the contiguous United States, until they were hunted to near extinction. I’m sure you’ve heard the story. But now they’re back! Grazing is a crucial disturbance in prairie habitat, providing habitat for a lot of species and open space for a lot of plants. But how will birds respond to this large, iconic grazer on its new home in Franklin Grove, Illinois? When I started my graduate degree at Northern Illinois University in 2013, I was able to start trying to answer that question more specifically by looking at how their nests were going to be impacted by bison.
Bison can impact bird nests in a variety of ways. There are the obvious negative direct ones like trampling and dislodgement, but there are also some not-so-obvious impacts. These impacts can be either positive or negative and can affect the nesting habitat, nesting material, clutch size, and ultimately the survival of the chicks until they leave the nest (nest success). Seeing if bison are impacting nest success means I must find the nests first. This is the most difficult part. They are roughly the size of a compact disc, made from the vegetation they are in, and wickedly hard to find. If you come by Nachusa early in the morning this summer, I’m sure you’ll see me walking in the prairie, waving around a stick, and waiting “patiently” for a bird to fly from the vegetation.
Although difficult, watching these nests through time is a very rewarding experience. I’ve seen nests being built, eggs being laid, chicks hatching, and chicks leaving the nest. Please don’t try this at home, though. Nests are sensitive to human disturbance, and I follow specific protocol to not influence their nest success. Bison don’t seem to be influencing their nest success either, negatively or positively. This is good news. They are one of the main sources of disturbance in the prairie, and it is a relief that they are not trampling nests of birds in decline, at least four years post-reintroduction. Watching these nests is only a part of my graduate research. I am also looking at how bison may influence nest predators, brood parasitism by brown-headed cowbirds, and what bird species are present. So far, I am not seeing anything change enough to be consider a bison impact. Time will tell if there will ever be a noticeable impact of bison on grassland birds. If I were here in ten years, I would try to find out.
The beautiful prairie and bison are a great reason to visit Nachusa, but don’t forget about the birds. Sure, they all look similar and are hard to spot, but they are our harbingers of spring and make the prairie sing in the summer.
Heather Herakovich is a PhD graduate student at Northern Illinois University. Heather studies grassland bird nest density, nest success, and species composition in restored plots of varying age as well as remnant control prairies. Heather is attempting to quantify the effects of bison reintroduction, prescribed fire, and restoration age on grassland bird populations at Nachusa.
As a native of Utah, I never gave much thought to tall grass prairies. I was always obsessed with the mountains, assuming I would work in that ecosystem. Yet, here I am in Illinois, working in a tall grass prairie for my thesis. Although I never anticipated ending up here, I am so glad that I did.
My advisor, Dr. Holly Jones, introduced Nachusa to me as the perfect place to conduct research. It has a chronosequence of sites, a bison unit, a non-bison unit and units with different burn intervals. I understood what she meant by the perfect place, but I couldn’t fully appreciate it until I became immersed in the potential of Nachusa. I am continually finding myself inspired with new research questions and ideas, to the point where I swear I could stay here forever.
My research interests revolve around predators. Predators have fascinated me since I was a kid pretending to be a lion. There is a beauty and grace about predators. They are fierce, powerful, and incredibly influential in an ecosystem. Predators can shape an entire ecosystem through hunting, creating fear that results in behavioral changes in their prey. These effects can ripple down the food web all the way to impact decomposition.
Nachusa is unique place to study predators. Historically, wolves were the top predators here. Since they were driven to local extinction in the 1800s, coyotes have taken over that role. This change in “top dog” has major implications for the way an ecosystem functions and which prey species are most abundant. That in itself is interesting. However, in addition, Nachusa is a rich and diverse landscape surrounded by agricultural fields. These conditions can be very supportive of coyote and fox predators. Furthermore, I discovered that the coyotes at Nachusa are depredating a state-listed turtle species many of us know and love: ornate box turtles. This makes understanding the role coyotes play at Nachusa even that much more important.
My research focuses on how coyote removal impacts small mammal prey species. Using stable isotope analysis, I investigated the diet of coyotes at Nachusa. The first step in the process was getting tissue samples from consumers (i.e. coyotes) and all the prey sources they ate. I tried countless times to entice coyotes to non-invasively “donate” their fur, but they just wouldn’t cooperate. In the end, the supportive community at Nachusa graciously collected nasty hair samples from road kill for me. (Thank you all so much!)
I’m currently looking at seasonal effects on coyote diet; the coyote hair is cut into segments and examined. Food availability in the prairie shifts over the seasons, so this method could provide some interesting insights as to what coyotes are eating when. Potentially, this could tell us more about when ornate box turtles are at highest risk for coyote depredation!
We now know that the Nachusa coyotes are opportunistic, generalist feeders. They hunt and eat small mammals in the greatest proportion collectively, but have a wide variety of dietary items. This is hardly surprising considering the menu of small mammals that are out there!
I have come to love Nachusa and each and all of its ticks. I can’t believe my time as a researcher here is coming to an end. Not only have I fallen in love, but my family has too. We will miss and cherish our time spent at Nachusa.
Kirstie Savage is a graduate student in the Department of Biological Sciences at Northern Illinois University. To read more about her work, visit the Jones Lab webpage.
Nachusa’s small creatures help citizen scientists monitor stream quality. Collection, identification, and a tally of macro-invertebrates from the local streams are used as an indicator of stream health. The monitoring is done through a statewide program called Illinois RiverWatch, established to help determine stream water quality throughout the state and provide a warning of potential problems. At Nachusa, the program was started in the spring of 2014 before the bison arrived, so RiverWatch is not only used to monitor stream health, but also to help identify changes due to their introduction. This is the fourth year collecting RiverWatch data in three Nachusa streams: Wade Creek, Clear Creek, and Johnny’s Creek.
Illinois RiverWatch trains citizen scientist volunteers to collect, identify, and preserve important indicator species of macro-invertebrates found in streams throughout Illinois. Macro-invertebrates are invertebrates large enough to see with the naked eye. Examples include insect larva, snails, and aquatic worms. One person in the stream monitoring group is required to have the eight-hour RiverWatch training class; four hours in the classroom and four hours hands on in a stream. At Nachusa, we are fortunate to have several trained monitors and interested volunteers lead by Mary Vieregg. Others that often join in the fun are Cindy Buchholz, Mary Meier, Jan Grainger, Matt Friberg, Tim Ngo and myself. Interested people who have not been trained by RiverWatch can participate in the stream monitor with a trained lead.
A site is selected and the locations are documented and approved by RiverWatch. The same site and locations are used each year, so changes from year to year and over time can be observed. At the site, the first step is to mark off the sampling area with flags 50 feet and 100 feet upstream and downstream from the selected site. Then, a map is sketched marking stream contours, significant features, and the day's sample locations. In addition, water depths, stream velocity, stream color, and temperature are recorded. Lastly, the vegetation around the stream is noted, along with the amount of shade cover; the stream bottom substrate is observed and recorded. Pictures can be taken and included with the sample data. Much of this data is recorded after the dip net hits the water in order to minimize any disturbances to the stream and the macros living in it before the collection.
The preferred collecting tool is the dip net. Designed with a sturdy cloth sleeve and mesh bottom, water can easily pass through and allow macros to collect in the bottom. There are five stream habitat types that RiverWatch samples, using the dip net collecting techniques. In order of preferred use:
Once the samples are collected and placed in buckets, the challenge is to pull the fast-moving macros from their watery homes. This is done using a shallow white pan, forceps, eye droppers, and carbonated water to help slow the critters down. Once captured, the macro makes the ultimate sacrifice, as it is deposited in a vial of pure alcohol for later identification and recording. All the macros taken can be combined into one sample. Once all the macros are pulled from the shallow white pan and put in vials, the gear is packed up and the crew returns to the barn for lunch. After lunch the work of sorting, identifying and counting begins.
Macro invertebrates can be seen with the naked eye, but for identification some of the key differences only become clear under a microscope. For example, mayflies fall into seven categories and key features on the gills, legs, and antennae are more easily seen through a microscope. Damsel fly larva, whether broad-winged or narrow-winged will determine their indicator number. Dragonfly larva are large and don’t need to be identified down to species, only that they are present and the number found. The process of identifying, sorting, counting is continued until the specimens are determined and recorded. The vial containing all the day's collection is labeled and sent to the RiverWatch administrator, who then forwards it on to professionals who double-check identification and the count. Feedback is then provided to the citizen scientist to help improve identification in the future.
Each macro used as an indicator species is assigned a number. The lower the number, the more conservative the species and the less tolerant of pollution and other disturbances. A formula, based on the assigned number of each species, the total count of each species, and the number of organisms found, is used to determine the Macro-Invertebrate Biotic Index (MBI). The lower the MBI number, the higher the stream quality.
Nachusa stream quality is good in Clear Creek and fair in Wade and Johnny’s Creek. It is too early to see a trend in improvement or degradation of water quality. An effort is made to sample the streams close to the same date each year, but an annual variance in weather conditions can account for some difference in the MBI. Only after many years of monitoring are trends likely to be seen. Following the introduction of bison, changes to the stream banks have been observed. In the sample area around Johnny's Creek, the vegetation has been eaten or trampled. Stream banks that were heavily vegetated are now bare. Near Wade Creek bison hair was found on the plants, but no disturbance was noted in the Wade Creek sample area. The changes in streams being made as a result of restoration efforts and the introduction of bison won't be measured in months or even years, but in decades and centuries. Careful observation, good science, sometimes unnerving patience, and prudent management will help restore the portions of these streams that run through Nachusa back to a functioning and evolving ecosystem.
Note: Clear Creek is outside of the bison enclosure.
To volunteer for the RiverWatch program at Nachusa, contact Mary Vieregg. For more information about citizen scientist training, visit the website for Illinois RiverWatch .
The blog today was written by Paul Swanson, a volunteer citizen scientist for Nachusa.
By Dr. Nick Barber
The bison reintroduction has been exciting for everyone involved with Nachusa—staff and stewards, volunteers and visitors, and especially scientists. The project provides a unique opportunity to measure the impacts of these animals and their actions on the entire restored prairie ecosystem. I’m fortunate to be part of a small army of researchers and students working closely with Nachusa personnel to understand how bison influence plants, animals, and other organisms.
Anyone who has had the opportunity to spend time within the bison units over the past 2 years has undoubtedly seen evidence of these giant herbivores: dung! In addition to grazing on plants and wallowing in dirt, bison play an important role in nutrient cycling by depositing concentrated piles of plant material and nutrients around the prairie. Across the landscape, this may provide hotspots of growth for some plants, adding to the overall diversity at Nachusa.
An inconspicuous group of insects help to carry out this nutrient–cycling process. Dung beetles feed on animal waste, and many species collect dung as a food source for their offspring. Some species famously form it into spheres, and roll these “dung balls” away to bury and deposit eggs. Other species tunnel below the dung patty, building chambers where dung is stored and beetle larvae can develop. And some species are “dwellers” who simply dive in to fresh dung and start to feast, laying eggs along the way. When these eggs hatch, the larvae feed, pupae, and emerge as adults, completing their entire metamorphosis in a single patty before heading off to mate and start the process over again in fresh patty.
Burying small bits of dung in the soil helps make nutrients accessible to plant roots. In the soil, microorganisms like bacteria and fungi convert organic materials into inorganic forms available to plants. This can represent a significant amount of the nutrients. As dung dries, much of the nitrogen can be lost to the air as ammonia volatilizes. This is why dung beetles are important for ranching: every bit of nutrients back in the soil rather than lost to the atmosphere means more fodder for livestock.
So it was a reasonable assumption that the dung beetle community at Nachusa would respond positively to the introduction of several dozen large, dung-producing herbivores to the prairie. I credit Dr. Ken McCravy from WIU for first suggesting that we should investigate these communities. Over the past two years, with support from the Friends of Nachusa Grasslands, I have been working with NIU students to survey the dung beetles to determine which species are present and how their abundances differ between sites with and without bison. We use pitfall traps, baited with fresh bison dung, to collect beetles that are later pinned and identified under a microscope in my lab at NIU.
Our preliminary results are exciting: we have documented at least seven species, including rollers, tunnelers, and dwellers. The two most common species are Onthophagus hecate, a widespread species, and Onthophagus knausi, a uncommon species whose range extends west and south through Kansas, Oklahoma, and Texas. The other species are much less common but include the large, blue-black Geotrupes opacus and the spectacular rainbow scarab, Phanaeus vindex.
As a preliminary result, the presence of bison doesn’t seem to have a big effect on abundance, as some bison-free sites have high numbers of beetles. But this may not be surprising given how mobile these insects are. They can fly and specialize in seeking out their preferred food. Cattle pastures surrounding Nachusa likely provide population sources as well.
Over the next two years, we will be investigating these dung beetle communities in more detail. A Master’s student at NIU will be combining observations of dung decomposition with beetle measurements to understand how different species contribute to dung processing. Ultimately we hope to understand how the management actions that maintain high plant diversity at Nachusa (such as prescribed fire and grazing) affect beetle communities and their ability to process dung.
Keep an eye on fresh dung patties and you may see these small but fascinating insects carrying out some of the invaluable “dirty work” that keeps the prairie ecosystem healthy and biodiverse!
Nick Barber is an assistant professor in the Department of Biological Sciences at Northern Illinois University. To read more about his work, visit the Barber Lab webpage. Thank you Nick, for being our guest blogger this week!
As I prepare this week to graduate with my Master’s degree from Northern Illinois University, I found myself reflecting on how much my experience at Nachusa shaped my life. I fell in love with Nachusa in 2013, after a volunteer work day collecting seed for one of my courses at Northern Illinois University (NIU). After less than an hour out in the field, I realized how much natural beauty I had missed out on while growing up in “The Prairie State,” and I was determined to make a difference. Standing on that knob surrounded by smiling stewards, seeds and sunshine sparked an everlasting passion in me to conserve, protect, and connect communities to their natural areas.
I was honored to research the effects of bison grazing and prescribed fire on small mammal communities at Nachusa for my graduate degree. Being able to witness the reintroduction of bison to the prairie and to be part of the team of scientists documenting their impacts is a once in a lifetime experience that I will cherish. I had the privilege of witnessing first–hand how different mice, voles, and ground squirrels thrive in this ecosystem filled with towering grasses and successional bursts of flowers.
Bison are truly amazing and I honestly was clueless as to how they would influence my research, and the herd always made sure to keep me guessing. It is really no joke that bison can be hard to find in the tallgrass, and I spent just as many hours fascinated watching them as I did capturing little critters. In early 2015 when I first saw that they had been through one of my trapping sites, I laughed because they had kicked around a few traps and bent over poles marking where the traps were, making the message loud and clear that my equipment was apparently in their way as they grazed.
That following summer I saw many bison grazing patches dotted with the peaking heads of 13–lined ground squirrels and began to capture them more frequently in the areas the bison stuck around in. It was surprising to me how quickly the deer mice returned to the areas that were recently burned, making them appear like giants among the emerging vegetation. The elusive capture of specialist small mammals like the western harvest mice and meadow jumping mice were always a treat to photograph. From the excitement of not knowing which little small mammal I was going to capture to the increasingly frequent “bison delay,” my adventure was filled with many fun experiences that definitely made me a prairie enthusiast for life.
My time at Nachusa documenting this healthy and diverse ecosystem, filled with so many amazing small mammals, are among the best memories I have spent with friends and family. Watching the seasons and the colors of the flowers change was always the highlight of my time out there. I will never forget the colors of that first sunset and how the fog rolled between the remnant knobs as the sun came up the next morning. At that time I never would have guessed that capturing adorable small mammals in this breathtaking landscape would bring so many people of diverse backgrounds together.
Sharing my time with all of you in the prairie truly inspired me to pass on the Nachusa spirit and help connect more people with their natural areas. Recently I accepted a position with The Nature Conservancy in Ohio as their Conservation and Volunteer Coordinator. I can only hope that I am able to pass along even a small bit of the Nachusa spirit that makes us more than volunteers or nature enthusiasts, but rather a family working together for the benefit of everyone through restoring and protecting nature. For this I graciously thank the amazing people who made Nachusa my home away from home and for a prairie state of mind . . . now and forever.
Today’s author is Angie Burke, a graduate student and researcher from Northern Illinois University. To read more about Angie's research, visit The Jones Lab at NIU.
I am a nature photographer, a freelance graphic designer, and steward at Nachusa's Thelma Carpenter Prairie. I have taken photos for Nachusa since 2012.
I have been a high school French teacher, registered piano technician, and librarian. In retirement I am a volunteer historian at Lee County Historical and Genealogical Society.