By Elizabeth Bach
Research Scientist at Nachusa Grasslands, The Nature Conservancy

Nachusa has experienced several ups and downs in 2021. COVID-19 continued to bring challenges and require flexibility. We celebrated the opening of our new equipment barn, but we also grieved the loss of naturalist Wayne Schennum. Wayne conducted plant and insect surveys at Nachusa throughout his long career and was actively working on a survey of leaf beetles prior to his passing this summer. Amid this uncertainty, the Nachusa science community managed to accomplish a lot.

• 40 scientists conducted research at Nachusa in 2021.
• Friends of Nachusa Grasslands awarded $62,335 in science grants.
• We have a new science space at Nachusa! The space includes a refrigerator, chest freezer, drying ovens, -80° C freezer, sink, counter space, and an outdoor porch working area. The science space is adjacent to the new seed-processing space. We are excited to welcome scientists into this shared space in the 2022 field season!
• Volunteers helped cross-pollinate Eastern Prairie Fringed Orchid flowers in June. This cross-pollination, both within the Nachusa population and among other populations. We hope this cross pollination will increase seed production.
• Nachusa scientists published 14 peer-reviewed scientific publications. Each publication is a major accomplishment, often the result of years of work. Congratulations to all authors! You can view a full list of all Nachusa scientific publications. Read on for an overview of this year’s findings.

Pete Guiden started 2021 strong with the publication of Effects of management outweigh effects of plant diversity on restored animal communities in tallgrass prairie in the Proceedings of the National Academy of Sciences. This is one of the top three scientific journals in the world; it is a major accomplishment for Pete and his co-authors in the Holly Jones and Nick Barber labs. It is significant for a Nachusa dataset to contribute to global scientific advancement in this way. They found management-driven responses were more common (and stronger) than plant-driven responses. Restoration age was the main driver of management effects, followed by prescribed fire. Both plant diversity and active management were critical to restoring animal biodiversity. You can learn more from Pete’s blog post. 
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Another significant Nachusa publication was Twenty years of tallgrass prairie restoration in northern Illinois, USA, published in Ecological Solutions and Evidence as part of a global special issue on the UN Decade on Restoration. Elizabeth Bach analyzed 20 years of plant survey data from permanent transects set up by Bill Kleiman. Plant communities on native prairie remnants have maintained or increased plant diversity, including rare plants. Savannas maintained similar levels of plant diversity, but plant communities shifted from understories dominated by brush to herbaceous plants, including native grasses and flowering plants.

​The special issue on the UN Decade on Restoration also featured a paper from Bethanne Bruninga-Socolar and Sean Griffin. Variation in prescribed fire and bison grazing supports multiple bee nesting groups in tallgrass prairie showed that a mixture of fire and grazing on the landscape encouraged diverse bee communities by promoting bees with different nesting habits. Nachusa bees were primarily ground-nesting (90% of observed species), but stem/hole nesters (3.6%) and large-cavity nesters (6%) are also important parts of the community. This team also published Bee communities in restored prairies are structured by landscape and management, not local floral resources in Basic & Applied Ecology. Large-landscape restorations were positive for bees, as the relationships with floral diversity observed in previous work in small, isolated prairies did not hold up at Nachusa.

​Several Nachusa insect studies were published in 2021. Michele Rehbein, who surveyed mosquitoes at Nachusa for her PhD work at Western Illinois University, published A new record of Uranotaenia sapphirina and Aedes japonicus in Lee and Ogle Counties, Illinois. Both these mosquitoes are new records for the area and contribute to broader understandings of mosquito communities in Illinois generally. Azeem Rhaman published Disturbance-induced trophic Niche shifts in ground beetles (Coleoptera: Carabidae) in restored grasslands, summarizing his MS research with Nick Barber at San Diego State University. He found ground beetles consumed a wider range of food sources in areas with bison grazing, particularly with both grazing and fire.
 
Meghan Garfinkel, who earned her PhD from University of Illinois – Chicago, specifically examined insects present in bird diets. Using faecal metabarcoding to examine consumption of crop pests and beneficial arthropods in communities of generalist avian insectivores, published in Ibis, was the first study to leverage next-generation DNA sequencing to analyze diets of entire bird communities. Birds consumed more herbivorous arthropods (plant-eating bugs) compared to carnivorous arthropods (bug-eating bugs). Heather Herakovich published two papers on birds this year. In Impacts of a Recent Bison Reintroduction on Grassland Bird Nests and Potential Mechanisms for These Effects, she found that bison presence did not impact nesting density or vegetation structure, but nest success increased in the first two years after reintroduction. Heather evaluated birdsong to passively survey communities in Assessing the Impacts of Prescribed Fire and Bison Disturbance on Birds Using Bioacustic Recorders.  This dataset showed that having a mix of recently-burned, unburned, and grazed habitat in the landscape supported diverse bird communities, as different species have different habitat preferences.

​It was a strong year for animal publications from Nachusa. Rich King and graduate students Monika Kastle and Callie Golba published two papers about their work on Blanding’s turtle recovery in northern Illinois, including the Nachusa population. Blanding's Turtle Demography and Population Viability focused on modeling needs for Blanding’s turtle populations to sustain themselves. Blanding's Turtle Hatchling Survival and Movements following Natural vs. Artificial Incubation reported on the results from the 2020 release of Blanding’s head-start hatchlings at Nachusa and other sites. Survival rates were variable across the populations, and research continues at Nachusa to find the most effective ways to protect these turtles.
 
Publications of threatened and endangered species extended to plants as well. Katie Wenzell, who earned her PhD from Northwestern/Chicago Botanic Gardens, published Incomplete reproductive isolation and low genetic differentiation despite floral divergence across varying geographic scales in Castilleja in the American Journal of Botany. This work examined the genetic relatedness and floral variability of Castelleja sessiliflora (downy paintbrush) and C. purpurea (prairie paintbrush or purple paintbrush) across their geographic ranges. Both species are evolving, but C. sessiliflora is exhibiting genetic differentiation, whereas C. purpurea is exhibiting differences in flower shape without genetic changes. These are two different mechanisms driving similar evolutionary outcomes. Timothy Bell and colleagues explored population trends in the threatened eastern prairie fringed orchid in Environmental and Management Effects on Demographic Processes in the U.S. Threatened Platanthera leucophaea (Nutt.) Lindl. (Orchidaceae). They found regular burning and wet weather lead to greater blooming populations for the orchid.

​To evaluate landscape-level plant community and soil characteristics, Ryan Blackburn tested aerial imaging from drones in Monitoring ecological characteristics of a tallgrass prairie using an unmanned aerial vehicle, published in Restoration Ecology. Drone images did an adequate job of evaluating grass cover and mean dead plant cover, but more work is needed to refine this method.
 
Scientific accomplishments at Nachusa are making strong contributions to both scientific understanding and on-the-ground conservation and restoration efforts. Thank you all for being part of this. None of this could happen without the collaboration of scientists, volunteers, donors, The Nature Conservancy, and Friends of Nachusa Grasslands.

Many of the 2021 researchers were supported with a Scientific Research Grant from the Friends of Nachusa Grasslands. Donations to Friends can be designated to Scientific Research Grants. 

The Nachusa summer science externship is supported by The Nature Conservancy.

​By Chandler Dolan
Bumble Bee Technician

​At first glance, it’s easy to mistake a fritillary butterfly for the well-known monarch; both can be seen fluttering across the prairie during the summer months, are similarly-sized, and are orange with black markings. 

​In 2017 I spent the summer surveying for butterflies, particularly regal fritillaries and monarchs, in remnant prairies across the Loess Hills of Iowa. From my experience, the only way to get close enough to identify, or be fortunate to snap a photo of a butterfly is to move slowly and cautiously towards it as it’s fixed atop a flower, busily sipping nectar. Be prepared to pursue a fidgety butterfly for several yards as it swiftly drifts from one flower to the next. It took a great deal of practice and patience before I was able to become a stealthy butterfly ninja. Upon closer observation, the difference between a monarch and a fritillary butterfly becomes more apparent. 

​There are 14 species of greater fritillaries (genus Speyeria) and 16 species of lesser fritillaries (genus Boloria). Both have a widespread range and can be found across the northern half of the United States into Canada, in some southern states, and parts of Mexico. Greater fritillaries inhabit woodland openings, meadows, prairies, and other open habitats where violets are present, while lesser fritillaries primarily live in wet meadows and bogs. Although greater fritillaries are much larger than lesser fritillaries, it can still be difficult to tell them apart while in flight.

​In total, there are 6 species of fritillaries that call Nachusa Grasslands home: great spangled fritillary (Speyeria cybele), regal fritillary (Speyeria idalia), aphrodite fritillary (Speyeria aphrodite), silver-bordered fritillary (Boloria selene), meadow fritillary (Boloria bellona), and variegated fritillary (Euptoieta claudia). The most common, and easiest to approach, is the great spangled fritillary. Of these, the regal fritillary is the only state-threatened species. 

​A prairie-specialist species, regal fritillaries have drastically diminished throughout the Midwest, with only two localized populations remaining east of Illinois and several small isolated populations east of the Great Plains states and western Missouri.

Typically, fritillaries have one brood and one flight period from June to August. Females lay their eggs near violets (Viola spp.), the caterpillar’s main food plant, in shady areas on the underside of dead vegetation. Soon after, the larvae hatch, crawl into nearby leaf litter, and sleep through the winter without feeding. During late winter to spring, the caterpillars begin munching on newly-sprouted violets and mature rapidly. Once fully grown, they pupate for several weeks until an adult fritillary butterfly emerges. Clearly, without violets there would be no fritillaries! Luckily for fritillaries, Nachusa has 7 species of violets throughout the preserve, as well as plenty of nectar sources to choose from.
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Equally as important to their survival, adult fritillaries require a large variety of nectar sources from native and non-native plants. I usually see them on coneflowers, goldenrods, ironweed, blazing-stars, milkweeds, mints, clovers, thistles – just to name a few. Plant any of these, along with violets, in your butterfly garden, and maybe a beautiful fritillary will pay you a visit.