PACE Lab News – Population and Community Ecology (PACE) Lab

July 13, 2026July 14, 2026

INHS PaCE Lab at 2026 Joint Meeting of Ichthyologists and Herpetologists

The 2026 Joint Meeting of Ichthyologists and Herpetologists was held this past week in New Orleans. Several members of the PaCE Lab presented papers and posters during the meetings.

Rose Arnold presented: “Site-Level Variation in Detection and Demographic Health of Blanding’s Turtles (Emydoidea blandingii) in Illinois

Blanding’s Turtle (Emydoidea blandingii) populations in Illinois occupy small, highly fragmented sites due to the state losing more than 90% of its historic wetlands. Blanding’s Turtles are state endangered in Illinois and have low population densities, causing low capture rates in many areas. Additionally, fragmentation hinders surveys and detectability, making it difficult for managers to assess population demographics and identify the best conservation strategies. Robust detection probability estimates are essential because imperfect detection can bias vital demographic estimates. We estimated detection probability by pooling decades of capture data across five Illinois sites and found site was the strongest predictor among the 30 covariates we investigated (temporal, effort, and weather covariates). Next, we estimated the vital rates (survival, recruitment, and population size) of each site independently to compare demographic health across the five populations. By combining site-specific detection probabilities with vital rate estimates, we assessed and compared the overall status of each population. Our objective is to provide managers with a clearer picture of population status across the five sites to support targeted conservation efforts for Blanding’s Turtles in Illinois.

Joey Cannizzaro presented: “Integration of Genomic Data to inform management of Eastern Massasauga Rattlesnakes (Sistrurus catenatus) in Association of Zoo and Aquarium care”

Maintena

nce of genetic diversity and successful reproduction of captive stock is integral to the sustainability of zoological collections. However, many captive breeding programs suffer from low reproductive success, which increases inbreeding susceptibility and hinders conservation efforts. The Eastern Massasauga Rattlesnake (Sistrurus catenatus) is an imperiled viper that poses several challenges to captive reproduction. Specific aspects of female S. catenatus reproductive biology, such as long-term sperm storage (LTSS) and the ability to produce multiple paternity litters, reduce confidence in inferred ancestry and could alter current understanding of relatedness and genetic health of captive individuals. Studies are needed to determine how multiple paternity and LTSS impact reproductive success. Current genomic approaches can provide fine-scale measures of genetic diversity and relatedness, thus offering increased accuracy to programs aimed at making informed breeding recommendations. We will estimate genetic health and first-order relationships using high-throughput Restriction-site associated DNA sequencing (RADseq) of captive populations across the Eastern Massasauga Saving Animals From Extinction (SAFE) program in the United States. Results of this study will equip zoo husbandry managers with molecular pedigrees and metrics of inbreeding to make high-confidence pairing recommendations.

Claire Dietrich presented” “Initial Survey of Freshwater Turtle Assemblages at Nature Preserves Across Northeastern Illinois”

Urbanization of the Chicago metropolitan area has drastically altered the landscape of northeastern Illinois over the past two centuries. Once dominated by forest and marshy wetlands, the region is now characterized by dense urban centers highly fragmented by several major roadways. The resulting loss of natural habitat has impacted regional abundances of some turtle species, such as the state-endangered Blanding’s Turtle (Emydoidea blandingii). Despite modern environmental protections, fragmentation and degradation of the remaining habitat provide little opportunity for populations to expand or recolonize their former range naturally. We sampled 18 publicly owned forest preserves, conservation areas, and mitigation sites for aquatic turtles to determine species richness, diversity, and evenness of the present assemblages. Species richness ranged from 1 to 5, with most assemblages comprising common species considered resilient to anthropogenic disturbance, such as the Painted Turtle (Chrysemys picta) and Common Snapping Turtle (Chelydra serpentina). Diversity indices ranged from 0 to 1.31, while evenness indices varied from 0.38 to 1. We intend to continually reassess turtle assemblages at all sites on a five-year rotation to gain a long-term temporal understanding of demographic trends.

Dr. Michael Dreslik presented: “Adult Survival Drives Population Decline in the Spotted Turtle: Demographic Evidence from Three Decades of Mark-Recapture Data”

Conservation resources are finite, yet management for long-lived vertebrates often targets incorrect vital rates. Turtles counter low fecundity with increased longevity, accumulating reproductive output across decades, but elevated adult mortality eliminates decades of potential reproduction. The spotted turtle (Clemmys guttata), a state-endangered wetland species at the western edge of its North American range in Illinois, exemplifies the challenge. Long-term mark-recapture surveys documented the last populations in the urban greater Chicago region annually since 1987, producing a long record of demographic data. We constructed integral projection models from data incorporating size-structured vital rates (growth, survival, and fecundity) using hierarchical Bayesian models. Population growth rates at both sites fell below replacement, indicating decline. Elasticity analysis revealed adult survival as the dominant demographic driver, contributing far more to population growth rate than fecundity or juvenile survival. Stochastic projections confirmed substantial extinction risk under current conditions, particularly at the smaller population, where adult survival is also lower. Taken together, the IPM results strongly support a management approach focused on reducing adult mortality. Nest protection and headstarting programs, widely used in turtle conservation, showed minimal elasticity and should be treated as supplemental rather than primary strategies. The IPM approach and elasticity-guided management apply broadly to other long-lived, low-fecundity vertebrates where adult survival dominates population dynamics.

Zander Perelman presented: “Night time is the right time: Caudal luring in free-ranging Pygmy Rattlesnakes (Sistrurus miliarius)”

A form of deceptive signaling, aggressive mimicry is when a predator sends a signal which indirectly manipulates subsequent behavior of their prey, with prey behavior ultimately benefiting the predator. In snakes, aggressive mimicry is most often expressed as caudal luring; individuals use vermiform (worm-like) tail movements to mimic invertebrates and attract lizards and frogs, which are predators of the “invertebrates”, but prey of the snakes. Despite caudal luring being a relatively common foraging tactic, particularly in viperids, previous studies have predominantly investigated this behavior in artificial laboratory settings. Here, we used field videography to study the foraging ecology of a robust central Florida population of Pygmy Rattlesnakes (Sistrurus miliarius), a small pitviper that caudal lures. From our captured video of over 700 snakes, we documented nearly 100 unique caudal luring events, representing the largest caudal luring dataset for any free-ranging viper. Caudal luring observations can be categorized into three distinct types: 1) prey-elicited luring, 2) spontaneous luring, and 3) luring-and-leaving. Across all observations, we found that both snake age and time of day had a significant impact on caudal luring occurrence in Pygmy Rattlesnakes. Our results better our understanding of the influence of stimuli and ontogeny on caudal luring in Pygmy Rattlesnakes, and importantly, provide insight into the factors that favor deceptive signaling tactics.

May 29, 2026

New paper on using modeling to guide conservation efforts of the Hine’s Emerald Dragonfly

When surveying for new populations of rare species, particularly those with short active seasons like the Hine’s Emerald Dragonfly (HED), optimizing search effort is imperative. Two models were created and field validated as a guide for when, where, and for how long to search for novel populations of the Hine’s Emerald Dragonfly.

A species detection probability model was developed using surveys at known HED locations to determine the weather conditions and length of surveys necessary to determine that HED is absent from an area. A regional Species Distribution Model (SDM) was created to identify areas with the characteristics necessary for HED. To validate the model, a subset of those areas were surveyed for HED. Combined, these two models will help land managers prioritize surveys and protection of potential habitats for the federally endangered Hine’s Emerald Dragonfly.

Read the complete paper in the Journal of Insect Conservation

Kessler, Ethan J., J.M. Mui, and M.J. Dreslik. 2026. Integrating multi-scale species distribution modeling and field validation to guide conservation of the endangered Hine’s Emerald Dragonfly (Somatochlora hineana). Journal of Insect Conservation 2026 (30):48. https://doi.org/10.1007/s10841-026-00781-0

February 11, 2026February 11, 2026

Edmonds’ newest paper on illicit amphibian trade

Recent PhD graduate Devin Edmonds’ recent paper “Tracking the hidden trade of non-native pet amphibians in the United States,” was the subject of an ACES news release “Where’d you get that frog? Illinois study traces illicit online amphibian trade.”

graphic with data from abstract and a picture of a frog and a newt

Abstract

The global wildlife trade is contributing to biodiversity loss, with amphibians especially vulnerable and overlooked in trade regulations. The trade in pet amphibians is a growing area of concern, and though there are notable benefits from keeping amphibians, the trade is also associated with introducing invasive species, spreading diseases, and overexploiting wild populations. Despite such risks, we lack a full understanding of the origins of traded species and the ways they enter markets. We combined online ads and import records to analyze the sourcing and pricing of pet amphibians traded in the United States, identifying species likely sourced from domestic production and unrecorded channels. Of the 301 species sold online, we identified 30 advertised more often than expected from import records, indicating they are primarily produced domestically. We also found 18.1% of traded non-native species had no import record and were sold at a 40.4% premium. Brazil, China, and Colombia stood out as countries with native species that were unrecorded in import records. Import at the genus-level was the most common way unrecorded species arrived in U.S. markets, but we also found instances of mislabeling, laundering, and suspected smuggling. The greatest number of imports at the genus-level were from Madagascar, Malaysia, Tanzania, and Vietnam. Our findings show the value of combining classifieds data with import records to identify illicit trade pathways and a need for improved record keeping. To move toward sustainable trade, we advocate engaging with domestic breeders and consumers while improving amphibian identification tools for inspecting wildlife shipments.

Read the full paper in Biological Conservation

February 7, 2026February 5, 2026

Turtle Research at Midwest Fish and Wildlife Conference 2026

Half of the INHS PaCE Lab presentations at this year’s Midwest Fish and Wildlife Conference were about turtles, with 5 oral presentations and 1 poster presentation.

Devin Edmonds presented “Ditch Turtles: Movement and Habitat Selection of Blanding’s Turtles (Emydoidea blandingii) at the Southern Edge of their Distribution” co-authored with Ethan Kessler and Michael Dreslik.

Habitat use is an important aspect of a species’ ecology, especially for range-limited species or populations impacted by land use change. However, habitat use can exhibit range-wide geographic variation due to numerous factors, such as clinal variation in environmental conditions. Additionally, habitat availability may be constrained in anthropogenically modified landscapes by barriers or expanses of unsuitable habitat. We studied the spatial ecology of a Blanding’s Turtle (Emydoidea blandingii) population in central Illinois to learn about the species’ habitat preferences and movement in a wetland complex insularized by agricultural land use. A combination of radiotelemetry and GPS loggers allowed us to record 2,105 locations collected from 18 individuals from 2022–2024. Turtles frequently used agricultural ditches and channelized streams for movement, suggesting such overlooked habitat features can be important corridors. Using step selection functions to assess habitat selection, we identified vital habitat features. Our results show the importance of agricultural drainages in facilitating movement in heavily fragmented landscapes and are indicative of the habitat selection of species occupying suboptimal habitat. While our study illustrates potential adaptability to agricultural landscapes, further work is required to determine the viability of such populations in the face of a potentially hostile agricultural context.

Michael Dreslik presented “Transient Demographic Analysis for Conserving a Critically Imperiled Turtle” co-authored with Ethan Kessler, Rose Arnold, and Devin Edmonds.

Traditional population models often focus on long-term growth, obscuring critical short-term vulnerabilities. Such oversight can lead to ineffective or even detrimental conservation strategies when considering immediate environmental stochasticity and disturbances. Our study analyzes short-term, transient dynamics for two imperiled Spotted Turtle (Clemmys guttata) populations in Illinois using an Integral Projection Model foundation. We then apply a modern analytical framework to quantify inherent population volatility using scale-invariant metrics, followed by a transient stochastic population viability analysis. Our analyses identified specific vital rates driving short-term stability, which may differ from rates influencing long-term growth. Additionally, we quantified potential trade-offs between management actions promoting rapid recovery versus actions ensuring resilience. Ultimately, our work will provide managers with a robust and nuanced understanding of population stability and, hence, more effective conservation decisions.

Becky Blankenship presented “Ornate Box Turtle Response to Habitat Re-creation” co-authored with Michael Dreslik and Joseph Milanovich.

Agriculturally driven habitat loss is one of the greatest causes of biodiversity loss globally, with reptiles being particularly vulnerable to such losses. Due mostly to land conversion to agriculture, Illinois has lost over 99% of its historical prairies, with only 955 ha of remnant sand prairies remaining. The Ornate Box Turtle (Terrapene ornata) is considered “Vulnerable” to “Critically Imperiled” throughout most of its range and is listed as state-threatened in Illinois. Understanding the spatial ecology of Ornate Box Turtles is an important aspect of this species’ conservation because it is highly philopatric, returning to the same locations for nesting and overwintering, and having high levels of home range overlap between years. Although numerous factors influence Ornate Box Turtles’ spatial ecology, there is a lack of longitudinal research on spatial response to large-scale re-creation of habitat. Using location data collected for 11 turtles between 2014-2015, and 13 turtles between 2021-2024, I tested whether the conversion of agricultural lands back to sand prairie influenced home range size. I also examined habitat selection between the early and late restoration periods. The restoration period, number of location points, duration tracked, and sex did not significantly influence home range size. Overall, home ranges decreased by 68% after restoration; however, this was a result of individual variation rather than a response to restoration. The conservation of Ornate Box Turtles in Illinois is dependent upon the persistence and restoration of sand prairies, and land managers need to target restoration efforts to areas that are occupied and readily available to individuals.

Claire Dietrich presented “Initial Survey of Freshwater Turtle Assemblages at Public Nature Preserves in Northeastern Illinois” co-authored with M.J. Dreslik.

Rose Arnold presented “Identifying Predictors of Detection and Estimating Detection Probabilities of Illinois Blanding’s Turtles” co-authored with M.J. Dreslik.

Low detectability of cryptic and endangered species makes population monitoring challenging, requiring substantial time and resources, particularly for freshwater turtles. Robust monitoring and detection of populations provides managers with reliable demographic data for targeted conservation. A lack of demographic data hinders regional conservation goals, as is the case with the Blanding’s Turtle (Emydoidea blandingii) in Illinois. The demographic data needs are compounded by the species’ cryptic nature and rarity. Thus, timing monitoring periods when Blanding’s Turtle detection is maximized could guide and improve conservation efforts. To identify optimal periods, we constructed detection probability models using historic and current capture data from five occupied sites in Illinois. The models test detection hypotheses using temporal, effort, and weather covariates. Our findings will reveal when detection rates are maximized, therefore enabling more strategic and cost-effective efforts.

Chitra Basyal presented a poster on “Effects of Microplastic Pollution on Hematological Parameters of Spotted Turtles (Clemmys guttata)” co-authored with Laura Adamovicz, John Scott, Lee Green, and M.J. Dreslik.

Plastic consumption by animals is a major global concern, as ingestion and entanglement negatively affect physiology, survival, and reproduction across numerous species. Turtles are no exception, as their widespread presence in freshwater ecosystems makes them particularly vulnerable to microplastic bioaccumulation. As integral components of aquatic food webs, turtles can also transfer pollutants across trophic levels, underscoring broader ecological risks. Although the effects of microplastics on marine turtles have received increasing attention, the impacts on freshwater turtles remain poorly understood. This knowledge gap highlights the urgent need to investigate the effects of plastic pollution on freshwater turtles, particularly for endangered species. Our study represents a pioneering effort to address this gap by examining plastic ingestion in adult female Spotted Turtles through fecal analysis, while simultaneously assessing hematology. Results revealed a high prevalence of microplastic pollution even within protected habitats. Understanding these impacts is essential for developing effective conservation strategies and mitigating the broader ecological consequences of plastic pollution.

February 6, 2026February 5, 2026

Snakes in Winter at Midwest Fish and Wildlife Conference 2026

two men standing — Drs Dreslik and Kingsbury before the Snakes in Winter symposium

Three of the 10 presentations by the INHS PaCE Lab were part of the Snakes in Winter Symposium organized by Bruce Kingsbury.

Dr. Dreslik presented “Fidelity to Over-wintering Refugia in the Eastern Massasauga (Sistrurus catenatus)” with co-authors Emily L. Sunnucks and Zander E. Perelman.

Colder seasons associated with latitude or elevational changes often influence the behavior and physiology of ectotherms. For temperate-zone snakes, suitable overwintering sites tend to be limited, forcing high rates of fidelity and even vernal and autumnal migratory events. The Eastern Massasauga (Sistrurus catenatus), a federally threatened rattlesnake, relies on specific refugia such as crayfish burrows at their southern range limit. Our study explores the spatial and temporal fidelity to overwintering sites using mark-recapture data (1999 – 2025) and radio-telemetry data (2000 – 2003) collected near Carlyle Lake, Illinois. The research quantifies whether snakes show fidelity to specific overwintering sites and if variation in fidelity is explained by sex and size. We also examine if active season movements centered on previously used refugia. With long-term data, we aim to improve the understanding of overwintering behavior and its conservation implications in fragmented landscapes.

ARC lead Ethan Kessler presented “Drivers of Autumnal Retreat and Vernal Emergence from Overwintering Refugia in the Eastern Massasauga (Sistrurus catenatus)” co-authored with MJ.Dreslik.

Annual survival in temperate snake species is dependent upon brumation in overwintering refugia, which protect individuals from harsh winter conditions. The timing of refugia use has novel implications in the face of anthropogenic threats, including the timing of prescribed burns and other intensive habitat management techniques. Understanding triggers of autumnal retreat and vernal emergence is crucial for scheduling habitat management activities, which improve habitat quality but can cause incidental mortality. We used a radiotelemetry dataset of the federally threatened Eastern Massasauga (Sistrurus catenatus) in Illinois, consisting of 4,822 locations (2000-2003 and 2008-2009), to determine the drivers of hibernacula use. We found the interaction of day of the year and soil temperature best predicted burrow use in the fall and spring. Lower soil temperature prompted burrow use in early fall and delayed emergence in late spring, but was less predictive in winter months as burrow use became nearly universal. Our study offers insight into the overwintering ecology of S. catenatus, while also providing a predictive model of burrow use based on easily measured variables, creating a practical tool for land managers to schedule activities and minimize mortality.

PhD candidate Zander Perelman presented “Overwinter Burrow Sharing by Eastern Massasaugas (Sistrurus catenatus) in South-Central Illinois” co-authored with Donald Shepard, Benjamin Jellen, and M.J. Dreslik.

Surviving winter is challenging for temperate-zone ectotherms and suitable refugia can be limited, especially at northern latitudes. Such harsh environmental pressures have driven the evolution of physiological and behavioral adaptations that increase overwinter survival. One such behavioral adaptation is communal denning, where natural features provide refuge for multiple individuals or species to overwinter together, sometimes at the scale of hundreds (e.g., Timber Rattlesnakes; Crotalus horridus) or even thousands (e.g., Red-Sided Gartersnakes; Thamnophis sirtalis parietalis) of individuals. Although Eastern Massasaugas (Sistrurus catenatus) occur near the northern range limit of temperate-zone pitvipers, they typically overwinter solitarily using refugia such as crayfish or mammal burrows, tree root systems, bedrock cracks and fissures, wetland hummocks, and spring seeps. No studies have explicitly examined Eastern Massasauga communal use of overwintering sites. Here, we used observations made during radiotelemetry study to characterize the frequency, demographics, and species diversity of overwinter site sharing in a population of Eastern Massasaugas in south-central Illinois. We found Eastern Massasaugas occasionally shared crayfish burrows (~7% of the time; 134/1970 total observations of Eastern Massasaugas in crayfish burrows) with both conspecifics and heterospecifics, and we examined how sex and life stage possibly influence burrow sharing. We discuss potential future research directions and the conservation implications of overwinter site-sharing behavior in Eastern Massasaugas and other imperiled temperate-zone snake species.

February 5, 2026February 5, 2026

Midwest Fish and Wildlife Conference 2026

INHS PaCE Lab made a huge contribution to the 2026 Midwest Fish and Wildlife Conference with 10 oral presentations and 2 posters.

While two herp symposia were dominated by the PaCE Lab, “Snakes in Winter” and “Research to Inform Management: Conservation of Freshwater Turtles and Other Threatened Amphibians and Reptiles in the Midwest,” ornithologist Asya Rahlin, malacologist Sarah Douglass, and Environmental Ed Program lead Jen Mui showed that we study more than just herps in the PaCE Lab.

UBAP lead, ornithologist Anastasia Rahlin presented “Using bird blood metabolites to assess wren food limitation” in the “Emerging Technologies and the Future of Bird Conservation” symposium.

Physiological biomarkers offer an underutilized tool for understanding how birds cope with food limitation and environmental stress. Blood metabolites such as glucose, ketones, and triglycerides provide real-time indices of energetic condition that can be linked to food availability, body condition, and resilience to extreme weather events. Using rapid point-of-care devices in the field, we measured metabolite levels in Marsh and Sedge Wrens across multiple breeding seasons in Illinois wetlands. These data revealed patterns of short- and long-term food limitation, as well as blood metabolite shifts following re-nesting attempts linked to periods of heavy rainfall and drought. Integrating metabolite monitoring into field research offers new opportunities to assess habitat quality, anticipate population responses to climate extremes, and potentially link individual physiology to habitat quality and population resilience. To complement these physiological data, we are piloting using fecal metabarcoding to identify songbird insect prey and explore links between prey availability, diet composition, and food quality, with management implications for birds and pollinators. Future research will integrate field and molecular diet data with metabolite measurements to assess energetic value of insect prey, and determine whether shifts in prey availability across the Chicagoland region impact bird health and breeding activity during the breeding season. Together, these approaches demonstrate how blood metabolites, paired with emerging molecular tools, can discover links between environmental change, prey dynamics, and bird health.

Freshwater Mollusk Ecology and Conservation lead Sarah Douglass presented “A Decade of Detection: Monitoring Freshwater Mussels After Bridge Expansion” co-authored with M.J. Dreslik in the “Bridging the Divide: Wildlife Connectivity, Crossings, and the Future of Transportation Ecology in the Midwest” symposium.

Robust long-term monitoring programs are well established for certain faunal groups yet remain limited for freshwater mussels. Many freshwater mussel species are long-lived, inhabit dynamic lotic environments, and face numerous threats including water quality degradation, barriers to host fish dispersal (e.g., dams), invasive species, and habitat loss. Increasingly, mark-recapture methods are being employed to assess the effectiveness of mitigation strategies in response to anthropogenic disturbances, such as bridge construction. When such activities pose risks to mussel populations, individuals are often relocated from impact zones. Over the past decade, we have conducted long-term monitoring of a freshwater mussel population in the Kishwaukee River (northern Illinois, USA) following a bridge expansion project. Our study aimed to evaluate apparent survival, detection probability, and movement patterns of marked individuals post-construction. Our findings highlight the value of individual-based monitoring in informing conservation strategies and improving our understanding of mussel responses to anthropogenic disturbance.>/p>

EEP lead Jen Mui presented a poster “The Traveling Science Center – Bringing Science to the People for 20 Years” co-authored with Patricia Dickerson.

Since 2006, the Traveling Science Center has been delivering environmental education directly to schools and communities across Illinois. Recognizing the challenges schools face to bring students to museums and nature centers, the Illinois Natural History Survey decided to bring the field trip to the schools. Housed in a 40 foot trailer, the TSC features hands on materials, and engaging exhibits on natural history and environmental science. Our modular design allows us to easily incorporate emerging research topics and support the broader impact and citizen science goals of our researchers. Over the past 20 years we have engaged students from more than 200 communities in Illinois and we will share our methods and lessons learned.

July 31, 2025July 28, 2025

New paper on the imperiled Rattlesnake-master Borer Moth

Rattlesnake-master Borer Moths, Papaipema eryngii , are an imperiled species, that has had little genetic analysis done. A new paper from INHS PaCE Lab, led by affiliate Donald B. Shepard, examines the genetic diversity of this species across its range, information necessary to accurately inform management actions and Species Status Assessments.

Shepard and colleagues were able to collect legs of 72 specimens from the extensive collections of J. Wiker and J. Bess, representing 6 of the 8 states with historical records of the species. Mitochondrial haplotypes were shared in geographically separated populations indicating they were likely connected when their open grassland habitats were more expansive. Habitat corridors between existing populations can improve gene flow and prevent inbreeding.

Additional sampling and genetic analysis may be necessary to capture the more recent genetic shifts of populations separated by habitat fragmentation.

Read the full paper in Journal of Insect Conservation

Shepard, D. B., J.R. Wiker, J.A. Bess, T.L. Esker, J.A. Crawford, and M.J. Dreslik. 2025. Genetic Diversity and Historical Demography of the Imperiled Rattlesnake-Master Borer Moth (Papaipema eryngii). Journal of Insect Conservation 29 (4): 59. https://doi.org/10.1007/s10841-025-00698-0

Find more about our research on Papaipema

July 25, 2025July 28, 2025

INHS PaCE Lab at Turtle Survival Alliance Symposium

Three members of the INHS PaCE Lab, Dr. Michael Dreslik, Emily Asche, and Claire Dietrich, attended the 23rd Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles, held in Chattanooga, TN July 20-25, 2025.

Emily Asche presented a paper “Assessing Population Structure and Conservation Priorities for the Western Pond Turtle (Actinemys spp.) on California Military Installations.” The paper was co-authored with Matthew Parry, Michael Dreslik, Robert Lovich, and Thomas Akre.

Abstract: The Western Pond Turtle (Actinemys spp.) is currently under review for listing as a Threatened species under the Endangered Species Act. Widespread population declines driven by habitat loss, predation, and shell disease have led to its designation as a Species of Special Concern in California, sensitive/critical in Oregon, and endangered in Washington. Despite regional protection, federal listing remains uncertain, emphasizing the urgent need for data to guide conservation. To address critical knowledge gaps, we conducted a two-year demographic study across 13 military installations spanning the species’ California range. Standardized week-long trapping sessions yielding data on body size, life stage, and sex. The metrics were used to estimate local abundance to establish a baseline to inform population health and trajectory. Our analysis revealed variations in demographic composition, site-specific abundance, and growth dynamics across installations, identifying high-risk populations and areas with potential recovery. Our findings are essential for prioritizing conservation actions, informing management of military lands, and contributing to range-wide assessments necessary for the species’ recovery planning.

Claire Dietrich presented a poster “Initial Survey of Freshwater Turtle Assemblages at Thirteen Nature Preserves in Northeastern Illinois.” The poster was co-authored with Michael Dreslik.

Abstract: Urbanization of the Chicago metropolitan area has drastically altered the landscape of northeastern Illinois over the past two centuries. Once dominated by forest and marshy wetlands, the region is now characterized by dense urban centers highly fragmented by several major roadways. The resulting loss of natural habitat has impacted regional abundances of some turtle species, such as the state-endangered Blanding’s Turtle (Emydoidea blandingii). Despite modern environmental protections, fragmentation and degradation of the remaining habitat provide little opportunity for populations to expand or recolonize their former range naturally. We sampled thirteen publicly owned forest preserves, conservation areas, and mitigation sites for aquatic turtles with baited hoop traps to determine species richness, diversity, and evenness of the turtle assemblages. Species richness ranged from 1 to 5, with most assemblages comprising common species considered resilient to anthropogenic disturbance such as the Painted Turtle (Chrysemys picta) and Common Snapping Turtle (Chelydra serpentina). Diversity indices were low overall, ranging from 0 to 1.19, but evenness indices varied from 0.38 to 1. We intend to continually reassess turtle assemblages at the sites on a five-year rotation to gain a long-term temporal understanding of demographic trends.

Dr. Dreslik presented a paper “Population Ecology of Spotted Turtles (Clemmys guttata) in Two Isolated Illinois Wetlands,” co-authored with Devin Edmonds, Rose Arnold, and Ethan Kessler.

Abstract: Over sixty percent of evaluated freshwater turtle species are assessed as at risk of extinction by the IUCN Red List. Overexploitation is the greatest threat, with habitat degradation, urbanization, pollution, and the ongoing effects of climate change also having large impacts. Consequently, many freshwater turtle populations are small, isolated, and declining, as is the case for the Spotted turtle (Clemmys guttata). The species has declined across its range in the eastern U.S., with only two populations remaining in Illinois at the western edge of its distribution. We conducted long-term capture-mark-recapture surveys and leveraged data collected over three decades to create demographic models of growth, survival, and reproductive output formulated into an integral projection model framework. The framework evaluates the probability of population persistence and how changes in vital rates affect population growth. Our results show the benefits of integrating size-based data sources for population assessments and the value of long-term monitoring, with implications for improving conservation efforts for Spotted Turtles in Illinois and throughout their range.

July 21, 2025July 21, 2025

PaCE Lab at 2025 Joint Meeting of Ichthyologists and Herpetologists

three people in front of a banner — Chitra Basyal, Rose Arnold, and Joey Cannizzaro at JMIH 2025

It’s herpetology conference season. This past week the PaCE Lab was well represented at the 2025 Joint Meeting of Ichthyologists and Herpetologists, held in St Paul Minnesota July 9-13.

Graduate students Rose Arnold, Chitra Basyal, and Joey Cannizzaro captivated audiences with their papers and oral presentations.

woman presenting scientific poster — Rose Arnold presenting at JMIH 2025

Rose Arnold presented a poster “Gauging Population Health in Urbanized Landscapes: A Body Condition Comparison of Illinois’ Remaining Spotted Turtle (Clemmys guttata) Populations.” Abstract: Urbanization has altered the hydrology and vegetation structure of many remaining wetlands in the United States. Hydrological and vegetation shifts can alter food availability and disrupt food chains, thus impairing energy flow among trophic levels. For wetland species to persist in altered habitats, managers should promptly develop strategies prioritizing the most vulnerable populations. In some cases, land managers must evaluate population health using short-term data, which can be difficult with long-lived turtle species due to extreme longevity and delayed sexual maturity. Body condition indices (BCI) are commonly used as proxy measurements of body fat, which are assumed to reflect foraging success and fitness of individuals. Body condition can change rapidly in response to resource availability, disease, and stress, making it a viable surrogate for assessing short-term population health. A population with significantly lower body conditions may indicate chronic stressors or fewer site resources. The two extant Spotted Turtle (Clemmys guttata) populations in Illinois inhabit sites within a heavily urbanized landscape and previous studies revealed differences in demography and microhabitat composition. Here, we compare body conditions between the two remaining populations of Spotted Turtles in Illinois as an additional measure of population health.

Chitra Basyal presented a talk “Structure of freshwater turtle assemblages in a highly developed ecosystem.” Abstract: Freshwater turtles play essential ecological roles in wetlands as omnivores, scavengers, food sources, and nutrient recyclers. Studying freshwater turtle assemblages is crucial because they are sentinel species when monitoring biodiversity and ecosystem health. Northern Illinois has undergone significant habitat modifications due to urbanization, agricultural expansion, and wetland loss, negatively impacting turtle populations. However, most studies in northern Illinois have primarily examined specific species rather than entire turtle assemblages. Our study aims to address the existing gap by investigating freshwater turtle assemblages across five urbanized sites in Illinois. Monitoring the sites used capture-mark-recapture surveys over an extended period; thus, we can assess species diversity, evenness, relative abundance, and richness across sites and years. Our research will determine if there are spatial and temporal variations in assemblage structure, highlight vulnerable species, and provide valuable insights into wetland health in northern Illinois.

person explaining poster to another person — Joey Cannizzaro presenting at JMIH 2025

Joseph Cannizzaro presented a poster “Effects of Vegetation Management on Predation Rates in the Eastern Massasauga Rattlesnake (Sistrurus catenatus). Abstract: Managing habitat to maximize survivorship and population growth is integral to recovering endangered species. Nearly all native tallgrass prairie habitats in the midwestern United States have been anthropogenically converted to agriculture. The decline in remaining habitat due to encroaching woody vegetation and invasive plants impacts many prairie obligate species, including the Eastern Massasauga (Sistrurus catenatus). Eastern Massasaugas requires open habitats and early successional vegetative assemblages to thermoregulate, forage, and reproduce. To reverse declines, many wildlife managers employ vegetative control practices, such as mechanical mowing and prescribed burns, to maintain early seral stages. However, conflicting evidence suggests reducing vegetative cover could lead to artificially higher or lower predation rates. We investigated the effect of early successional vegetation management on the predation rates of Eastern Massasaugas by conducting a clay model predation study. We placed models into two treatments, habitat recently managed for vegetative succession or adjacent unmanaged habitat, and scored them for predation marks. Additionally, clay models were made in two different body postures, outstretched and coiled, to investigate how body posture potentially influences snake predation rates. Our study presents the impact of recent vegetation management on predation rates and provides insights to inform future conservation efforts.

July 20, 2025July 29, 2025

New technique aids researchers in finding elusive mussel

A new paper in Ecology by Freshwater Mollusk Ecology and Conservation Program lead Sarah Douglass and colleagues describes the use of emerging technology paired with traditional methods to try to locate a species not seen alive in Illinois in over 100 years.

The Salamander mussel Simpsonaias ambiguahas been proposed for federal listing under the US Endangered Species Act. Despite intense surveys, live individuals were last documented in Illinois in 1906.

The Salamander Mussel differs from other mussel species in that instead of a fish species, it uses the Mudpuppy Necturus maculosus as host for its glochidia.

The emergence of environmental DNA (eDNA) techniques provides a new method to guides surveys for potential populations.

Sarah Douglass and colleagues collected samples at 8 sites in the Sangamon River to test for both Mudpuppy and Salamander Mussel eDNA. Mudpuppy eDNA was detected in samples from 4 sites, 1 of which also contained Salamander Mussel eDNA. A group of surveyors returned to that site and conducted targeted searches of preferred habitat, yielding 12 live Salamander Mussels, the first seen in Illinois in over 100 years.

Read the complete paper here

Douglass, Sarah A., Savanna Palmer, Ashleigh R. McCallum, Olivia P. Reves, Hayley A. Robinson, Allison J. Rutledge, Jordan H. Hartman, Eric R. Larson, and Mark A. Davis. 2025. Environmental DNA Reveals the Salamander Mussel Simpsonaias Ambigua Alive in Illinois, USA , after a Century in Obscurity. Ecology 106 (7): e70145. https://doi.org/10.1002/ecy.70145.