Genetic analysis shows that the Eastern Massasauga hibernacula at Carlyle Lake are genetically distinct units.
Once found across the northern two-thirds of Illinois, populations of the Eastern Massasauga have declined, with only one known population remaining in Illinois. Our long term studies have found the top four sources of mortality to include automobiles, predation, management related mortality (prescribed burns, mowing, etc), and disease. Our current study indicates that efforts to address these ecological threats may not be enough to save this imperiled species.
The area under what is now known as Carlyle Lake was a floodplain valley known as Boulder Bottoms. The creation of Carlyle Lake in the 1960s flooded this area, separating habitats on the the east and west sides of the Kaskaskia River, pushing wildlife, including the Eastern Massasauga, to the edges between the lake and agricultural fields. These bands of habitat are separated by the lake, paved roads, agriculture, and urbanization, potentially limiting migration and gene flow between patches.
Our current study looked at 327 genetic samples collected between 1999 and 2015 from individuals at 9 hibernacula across 3 study areas at Carlyle Lake. Study sites separated by up to 5 km had limited gene flow, as did hibernacula separated by a few hundred meters. This restriction of gene flow increases the vulnerability of these already imperiled populations.
Our study indicates that conservation and recovery efforts need to consider genetic rescue efforts in addition to reduction of ecological threats. Such efforts may include translocations and captive rearing to reduce the impacts of inbreeding depression and genetic drift. Even short distance translocations between the different study areas at Carlyle Lake could help restore gene flow impeded by contemporary human created fragmentation.
Anthonysamy, Whitney J.B., Michael J. Dreslik, Sarah J. Baker, Mark A. Davis, Marlis R. Douglas, Michael E. Douglas, and Christopher A. Phillips. 2022. Limited gene flow and pronounced population genetic structure of Eastern Massasauga (Sistrurus catenatus) in a Midwestern prairie remnant. PLOS ONE: https://doi.org/10.1371/journal.pone.0265666
This is the third intergovernmental agreement between the INHS and the Illinois Tollway and will allow the continuation of this mutually beneficial partnership that began in 2005.
The partnership has grown from monitoring Blanding’s Turtles in the Des Plaines River Valley to a multi-disciplinary program. While the key function is to provide the ecological knowledge necessary to comply with state and federal regulations, both organizations share a goal of studying the natural resources of the region to protect them into the future.
The first cooperative project is with the Iowa and Illinois Department of Natural Resources, allocated at $499,797 for the joint project titled “Blanding’s Turtle Conservation in Iowa and Illinois, 2022 through 2024”. The project team from the Illinois Natural History Survey (INHS) and National Great Rivers Research and Education Center (NGREEC) comprises Ethan J. Kessler, Michael J. Dreslik, Andrew R. Kuhns, and John A. Crawford. The team was awarded $249,449 for their portion of the project, “Population Assessment and Space Use in a Kankakee Sands Region Blanding’s Turtle Population.” While much work has been done on Blanding’s Turtle populations in the Chicagoland region, this project focuses on lesser-known populations in the Kankakee Sands Conservation Opportunity Area.
The grant will facilitate an intensive capture-mark-recapture study to determine population size and begin to collect demographic data. A subset of turtles will be tracked using radio telemetry and GPS trackers to monitor survival and determine space and habitat use. The data is necessary to determine the amount and extent of suitable habitat available on the landscape and address causes of mortality for this population. The work will build on previous research on Blanding’s Turtles in Illinois and further inform conservation planning.
The second cooperative project is with the Minnesota Department of Natural Resources allocated at $247,892 for the joint project titled, “Regional Assessment of Widespread Mussel Declines: a Multistep Approach to Examine Potential Causes.” The project team from the INHS comprises Sarah A. Douglass and Alison P. Stodola while INHS alum Bernard Sietman will lead Minnesota’s portion. The INHS team was awarded $113,364 for their portion of the project. Freshwater mussels, an ecologically important component of river ecosystems, are experiencing widespread declines. With the award, Douglass and Stodola will investigate potential causes for these declines with the goal of informing conservation guidelines and recovery planning. Additionally, this study is an expansion of a largescale, cooperative project spearheaded by Dr. Wendell Haag, US Forest Service Research Fisheries Biologist, and American Rivers to examine causes of freshwater mussel declines across North America.
Researchers will assess pairs of rivers with similar historic mussel assemblages, comparing a river with relatively intact mussel assemblages and a river with a degraded assemblage. They will develop health metrics and assess habitat characteristics to identify potential causal factors of decline. Juvenile mussels will be propagated and used to assess health in response to potential causes of decline. Another part of the project will use eDNA and targeted sampling to update knowledge of Salamander Mussel populations in Illinois and Minnesota. The research will build on a pilot project previously undertaken by Douglass to use eDNA to detect the critically imperiled species and its host, the Mudpuppy salamander.
In granting these awards, USFWS recognizes the necessity of these two projects to further the goals of the Illinois Wildlife Action Plan to conserve imperiled species and their habitats.
Eastern Box Turtle growth is influenced by environmental conditions which in turn can be influenced by vegetative structure. Removal of Autumn Olive and Russian Olive at a site in Illinois occurred during a 16 year mark-recapture study allowing us to analyze impacts of removal on the growth of turtles. The data showed that removing the invasive plants may not negatively impact the growth of the turtles and that growth is variable by individual. This is attributed to reptile growth being influenced by more than just environmental conditions, including genetics.
Champaign, IL – Protecting and restoring habitats are the most important steps that can be undertaken to protect turtle populations into the future according to a pair of recent papers analyzing 3 decades of data.
The Spotted Turtle, Clemmys guttata, is a small semi-aquatic turtle that inhabits sedge meadow, cattail marsh, wet-mesic prairie, and dolomite prairie in Illinois. It is protected as an endangered species in Illinois, which is at the western edge of its range. The two known populations in Illinois have been the focus of mark-recapture studies since 1988.
Recent analysis found that Spotted Turtle populations are limited by the amount of available habitat, suggesting that management efforts should focus on increasing suitable habitat. Control of cattails (Typha sp.) and restoration of sedges would increase the amount of available habitat.
Adults have a higher survival rate than younger turtles. Predators including raccoons and muskrats can eradicate eggs and juvenile turtles. While caging nests and headstarting juveniles will help the younger turtles, controlling predator populations could benefit all age classes.
Environmental DNA (eDNA) is an emerging tool used to detect rare and difficult to detect species. A recent study by INHS PACE Lab herpetologists used radio telemetry to evaluate and improve the efficiency of this technique.
As part of a species reintroduction program, hatchling Alligator Snapping Turtles reared in captivity were tracked using radio telemetry to assess their survival. This work provided an ideal system for evaluating the efficacy and limitations of using eDNA to detect a bottom dwelling riverine turtle. At each radio location, water samples were collected as well as upstream and downstream of the turtle.
The researchers found that eDNA can be used to detect a benthic turtle species but that detection can be diminished by UV exposure from open canopy. This study shows the importance of continuing to use traditional methods such as radio telemetry to better understand the dynamics of eDNA in the environment.