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