​By Chandler Dolan
Bumble Bee Technician

By John Vanek, PhD
Associate Wildlife Biologist®

​As scientists, we know a lot about snakes. We know that snakes evolved from lizards. We know that snakes don’t have eyelids or external ears. We know they can eat things bigger than their own head. Some species, like the black-tailed rattlesnake, are good mothers, stick around after birth, and protect their offspring. Recently, it was discovered the snakes can even have friends! Suffice it to say, snakes are awesome. So awesome, in fact, that some of us prefer them to grasshopper sparrows and fringed gentians (don’t hit me!). Yes, we herpetologists (scientists that study reptiles and amphibians) are a weird bunch, with our metal probes and pillowcases .  .  .  anyway, I digress.

​While we know a lot about snakes and how cool they are, we still have a lot to learn, particularly when it comes to ecological restoration. Unlike birds and insects, snakes don’t have wings. Snakes are also terrible at crossing roads (probably because they don’t have legs). So, the big question is if you build it, will they come? That is, if you go through the hard work of restoring an old ag field back to tallgrass prairie, will snakes recolonize the site? Dr. Richard King and I tried to tackle this question in a recent publication creatively titled “Responses of Grassland Snakes to Tallgrass Prairie Restoration.” In short, yes, but it’s complicated!

​Before we dive into what we found, how do herpetologists actually study snakes? It’s not like you can lean against a shady bur oak and listen for the sounds of singing snakes (yes, this is a playful dig at my ornithologist friends). One option is to simply walk around and look for snakes. This is, however, not very effective. Think of how many snakes you’ve stumbled across at Nachusa. Maybe a handful at most, right? Certainly not enough to do some fancy statistics. Nor will snakes stumble into a tiny metal box baited with peanut butter (sorry mammologist friends, I had to make it fair to the ornithologists!).

So, what is the intrepid herpetologist to do? We take advantage of a snake’s natural tendency to hide under things, so we employ something called “artificial cover object surveys.” What this means is that we put out things that snakes will hide under (in our case plywood boards and rubber mats), and then go back later and check each one. What does a check entail, you may ask? Great question, and the answer is simple: bend down, lift the board, and then try to grab every snake you see! Simple, but not easy; those little buggers are fast!

​Now the nuts and bolts of our study. To address the question of snakes and habitat restoration, we deployed approximately 240 snake boards across 12 restoration units (2–25 years since restoration) at Nachusa. We (ok, mostly Rich) checked each board roughly once a week from May to October from 2013–2016. This resulted in sacrificing our lower backs for science a total of 15,720 times over the four years. (The astute reader may notice the math doesn’t work out perfectly, and that’s because life often gets in the way of checking snake boards!) Was it worth it? You bet! Overall, we caught 1,028 individual snakes of four focal species: 90 plains garter snakes, 112 eastern fox snakes, 347 Dekay’s brown snakes, and 479 common garter snakes. Each snake was given a unique marking so we could identify it if captured again, and we also measured and weighed each snake. We also found a few other species in small numbers.

​Right off the bat, we see that all four species readily colonized tallgrass prairie restorations at Nachusa, which is great news! We also found that there was no relationship between restoration age and the abundance or occupancy of plains garter snakes, eastern fox snakes, or common garter snakes. That is, newly-restored sites were just as likely to have these species as older restorations. However, older sites were much more likely to have Dekay’s brown snakes than younger sites. This is a really cool finding, as Dekay’s brown snakes are the smallest of the four species (adults rarely exceed 18 inches), and they also have the smallest home ranges. This suggests that smaller species with limited dispersal capabilities might be slower to colonize restorations. Intuitive for sure, but it’s always great to have data!

​Finally, there was a glaring omission from our snake board data: we found zero smooth green snakes! This was really odd, as the species was once common across northern Illinois, and we found them to be relatively common at nearby Green River Wildlife Management Area. However, snakes can be really hard to find, so the question became, “Are smooth green snakes truly absent from Nachusa, or did we simply fail to find them?” To address this, we took our data from Green River and used a statistical technique called logistic regression to calculate something called a "detection probability". The results? Given our approximately 15,000 cover board checks, we estimated there was a 99.9% chance we would have detected them if they were indeed present at Nachusa. Could we have missed them? Certainly, but it is highly unlikely.

​​So, why are there no smooth green snakes at Nachusa? The most likely explanation is that they simply did not survive in the small remnants at Nachusa prior to restoration. Like Dekay’s brown snakes, smooth green snakes are quite small and are probably not so great at colonizing new areas. In addition, smooth green snakes specialize on eating insects and spiders, and they may be particularly susceptible to insecticide use relative to other species with broader diets. So, if they didn’t survive at Nachusa, crossing miles of roads and ag fields might pose too big of a challenge. Therefore, while a “wait and see” approach might work for other species (such as Dekay's brown snake), captive breeding and translocation may be necessary to establish populations of  smooth green snakes at Nachusa. This approach has shown great promise in the Chicago suburbs, and I hope one day to see the tail end of a smooth green snake slipping away into a tussock of little bluestem at Nachusa Grasslands.

In conclusion, we found that Nachusa boasts plentiful populations of at least four species of grassland snake, and these snakes are not limited to the remnants, but occur broadly throughout restoration units. Other species also occur, including the eastern hog-nosed snake, eastern milk snake, North American racer, and common water snake. However, the smooth green snake, a species that is common in nearby Green River Management Area, appears to be truly absent at Nachusa. I propose they be considered a candidate for assisted translocation or reintroduction, pending further study, of course.
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Thanks for reading! Have you seen any snakes at Nachusa? If so, what kind? Let me know in the comments, and feel free to send me an email for snake identification help from Nachusa or anywhere else! 

By Elizabeth Bach
Ecosystem Restoration Scientist
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It’s a chilly, rainy spring afternoon, and I sit in front of the computer. Yet I can feel the heat of a sticky August afternoon, hear the whine of cicadas, and see the golden blooms of sunflowers. Mentally, I’m systematically walking through the prairie, carefully identifying all the plants. At Nachusa, many of us, myself included, find working outside in the prairies, savannas, and wetlands most rewarding. However, there is an incredibly important part of conservation work that happens at the computer: data entry and analysis.

​As the staff scientist at Nachusa, one of my primary duties is to analyze and share data.  My primary tool for this work is a free program called “R.” In R, I can manipulate data, produce graphs, run statistical tests, and even produce a final report. Analyzing these data helps everyone at Nachusa refine restoration practices, inspires new ideas, and deepens our knowledge of the habitats and the organisms that live there. Sharing these data in presentations and publications allows us to share lessons learned and best practices used at Nachusa with others in both the conservation and scientific communities. In turn, we also learn from data from other sites. At Nachusa we are lucky to have several scientific researchers working at the site, who collect, analyze, and share data with us. We also have some data, collected over the years by The Nature Conservancy staff and collaborators, which haven’t been analyzed and shared. A key goal for Nachusa is to analyze these legacy datasets and share them.

​All this brings me back to my computer on an early spring afternoon. When there is less work to be done outside, I’m busy working with datasets on the computer, building graphs, thinking through which metrics best represent the observations made on the prairie, and building statistical models to understand how the Nachusa ecosystem has changed and how it might continue to change into the future. All this work is done with a few lines of code on the computer. While very different from the outdoor joys and challenges of data collection, there are both joys and challenges with this work.

​I often think of data analysis as a mystery to solve. What will the data show? What will I learn? How might this challenge or confirm observations from other scientists in other places? Every dataset is a new adventure, and I find a sort of excitement in that. It can also be frustrating. I spend a lot of time finding and correcting mistakes. There is no travel guide to inform my decisions. Fortunately, I can work with collaborators as travel buddies on these adventures, to bounce ideas off them, and gain a new perspective. One of the joys of working at Nachusa is being at the intersection of many paths of scientific research and natural history observation. Working with people with different expertise, skills, and perspectives deepens my understanding of science, the tallgrass prairie, and Nachusa.

​By Angie Burke
Volunteer Coordinator, The Nature Conservancy

​We are all familiar with the saying “It’s the little things that matter”, and it’s the management of the tallgrass prairies at Nachusa Grasslands that has made a big difference for the littlest of things— mammals. Our paper “Early Small Mammal Responses to Bison Reintroduction and Prescribed Fire in Restored Tallgrass Prairies”, coauthored with Dr. Holly Jones and Dr. Nick Barber, sheds light on how the varying management of prescribed fire, coupled with the reintroduction of grazing bison, has created a habitat haven for the small mammals in a mix of agriculture and rural development.
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blocking our safe  access to a site, to capturing meadow jumping mice awakening from their winter slumber, every sampling season held a new adventure for us. 

Some of the little buddies we captured and released were deer mice, white-footed mice, prairie voles, northern short tailed shrew, meadow jumping mice, harvest mice, and my favorite, the 13-lined ground squirrel. Rain, snow, or shine, the little buddies are welcomed to the study each season with excitement by the many stewards, volunteers, and scientists that call Nachusa home. 

​In the first two years since bison were reintroduced, we found fewer small mammals in older sites relative to new restorations and fewer as time since fire increased. Additionally, there was a higher diversity of what we did document in those older sites and slightly lower diversity (fewer than one species, on average) in sites where bison were present. This difference was driven mainly by prairie voles; fire removes litter and residual dead vegetation which is important habitat for voles. The overall abundance was especially influenced by the deer mice, which are able to use the areas with a higher prevalence of bare ground associated with frequent/recent fire on the landscape. 

​By Jess Fliginger
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