Tag: Turtles

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INHS PaCELab at 2024 Turtle Survival Alliance Symposium

This year’s Turtle Survival Alliance conference was held in Tucson Arizona 2024  July 25-28. Several members of the INHS PaCE Lab presented posters and talks, which we’re excited to share with you.
 
Dr. Dreslik gave a featured presentation during the plenary session,
“Freshwater Turtle and Tortoise Growth: What we know and where to go”
co-authored with Drs Lovich (USGS) and Congdon (Savannah River Ecology Lab).

Dr Dreslik at podiumGrowth is a fundamental life history trait expressed as shape, rate, and size at specific times for individuals in a population. Because energy allocated to competing life demands shifts, all expressions have impactful relationships with other life-history traits. In general, the overall growth pattern of turtles is well understood, but representative studies are decidedly lacking for many species and populations. Additionally, we are building a stronger foundation of the drivers and their consequences on growth; few studies have had the luxury of serially examining populations to determine environmental and habitat related effects. Herein, we present the state of knowledge on growth in freshwater turtles, covering aspects such as pattern, seasonality, determinism, dimorphism, extrinsic drivers, maternal effects, and individuality. Finally, we will provide insight into current analytical advances and direction for future work.

Graduate student Nicholas Dunham presented a poster
“Spatial Ecology of Blanding’s Turtles (Emydoidea blandingii) in an Agricultural Landscape in Northeast Illinois”
co-authored with Ethan Kessler, John Crawford and Michael Dreslik.
Agriculture in Illinois dominates the landscape, leading to widespread alteration of terrestrial and aquatic ecosystems. Much of Illinois’ freshwater wetlands have been heavily channelized and converted into vast networks of ditches in agricultural drainage systems. Thus, these agricultural ditches may represent some of the only available wetland habitats for turtles. A small population of Blanding’s Turtles (Emydoidea blandingii) was discovered living in an agricultural ditch system in Kankakee and Iroquois counties of Northeast Illinois. Blanding’s Turtles use terrestrial and aquatic habitats throughout the season, increasing their mortality risks from farming equipment. To better understand how Blanding’s Turtles utilize an agricultural landscape, we trapped and used VHF radio-telemetry to track 15 individuals (9 females, 6 males) from April to November 2023, totaling 533 locations. Our objectives were to investigate home range sizes, movement rates, and macrohabitat and microhabitat selection by sex and season. The results of our study are preliminary, and data collection will continue from 2024 to 2025. Our results can aid the management of Blanding’s turtles in agricultural-dominated landscapes.
Graduate student Emily Asche presented
“Population Structure of the Declining Western Pond Turtle (Actinemys spp.) Across Thirteen Military Installations in California”
co-authored with Matthew Parry, Thomas Akre, Robert Lovich, and Michael Dreslik.
The Western Pond Turtle (Actinemys spp.) is currently undergoing assessment to be listed as a Threatened species under the Endangered Species Act. It is designated as a species of special concern in California, sensitive/critical in Oregon, and endangered in Washington, indicating an imminent likelihood of listing. Habitat loss, predation, and shell disease have caused significant population declines, yet there remains a scarcity of data necessary for informed management decisions. Understanding the existing population structure of remaining populations is pivotal for initiating effective conservation strategies. We are gathering demographic data from thirteen military installations across their California range to assess the level of concern and identify key management priorities. Data collection spans two seasons, with sampling conducted in week- long intervals using 50 aquatic traps per base, supplemented by relevant data from prior or concurrent studies at each installation. Recorded parameters include body size, life stage, and sex of all individuals to characterize the population structure. Additionally, growth rate and recruitment will be derived from the final dataset. Our study’s objective is to delineate targeted conservation efforts for species recovery.
Rose Arnold presented
“Development of a Detection Model of the Blanding’s Turtle (Emydoidea blandingii) to Guide Conservation Prioritization in Illinois”
co-authored with Michael Dreslik
Woman presenting at podiumLike many turtle species, Blanding’s Turtle (Emydoidea blandingii) populations are declining range-wide due to the synergistic effects of habitat fragmentation, loss, and degradation. In Illinois, Blanding’s Turtle populations are isolated within urbanized or agricultural landscapes, thus hindering migration. Additionally, the status of the species at many historical locations remains unknown, whereby many populations may already be functionally extirpated. Thus, determining the status of populations in Illinois is the paramount conservation priority. Surveys for Blanding’s Turtles require a substantial investment of resources (time, funds, and effort) through trapping and visual searches. Currently, there are few tools for quantitatively determining the effort needed to confirm site occupancy. Here, we construct a detection probability model considering temporal, effort, habitat, weather, and environmental variables. The model will allow surveyors to calculate how much effort is necessary to determine occupancy status for a given site under a given set of conditions. The findings from the initial model sets suggest temporal factors exert the most influence on detection, particularly when compared to weather. However, even in strong-performing models, predicted detection rates remained low.
Chitra Rehka Basyal presented a poster
“Structure and Health of a Freshwater Turtle Assemblage in a Highly Developed Ecosystem”
co-authored with Michael Dreslik, Ny Aina Tiana Rakotoarisoa, Laura Adamovicz, and Matthew Allender
Turtles have important ecological roles in wetlands as omnivores, scavengers, food sources, and nutrient recyclers. Despite such importance globally, their populations are declining, with the proliferation of infectious diseases emerging as a major threat. Our study aims to assess turtle’s community structure and evaluate the physical health of those turtle individuals. We began a turtle capture-mark-recapture survey at a university wetland to study assemblage, composition and individual health. In our first year (2023), we captured 39 turtles of 6 species. Based on the species composition, our study suggests the site may be used for illegal pet releases. We screened 37 individuals for adenovirus, herpesvirus, ranavirus, and mycoplasma using conventional and quantitative PCR. Two species (Painted Turtle [Chrysemys picta] and Red-eared Slider [Trachemys scripta elegans]) were adenovirus-positive, with the virus strain being 99% similar to Sulawesi Tortoise adenovirus. No mycoplasma, Ranavirus, or herpesvirus was detected. Moreover, the Red-eared Slider is likely a natural host of Sulawesi Tortoise adenovirus (STAdV-1). The study forms a baseline for long-term demographic monitoring and health assessments of the turtle assemblage.
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New paper analyzing long term data on Ornate Box Turtle survival

box turtle
Ornate Box Turtle Photo by D. Edmonds

PaCE Lab doctoral candidate Devin Edmonds has a new paper in the journal Wildlife Biology: “Evaluating Population Persistence of Ornate Box Turtles (Terrapene ornata) at the Northeast Edge of their Distribution.”

This work analyzed 34 years of data from one site and 8 years of data from another to estimate female and juvenile survival and population growth over time. Being able to look at a population over a long period of time provides a better understanding of the population. This study also highlighted the need to protect adult female Ornate Box Turtles if the populations are to persist.

This work was co-authored with members of the Wildlife Epidemiology Lab.

 

Abstract: Turtles and tortoises are among the most threatened vertebrate groups. Their life history is characterized by delayed sexual maturity and a long lifespan, making populations susceptible to decline following perturbations. Despite the urgent conservation need, we are missing estimates of basic demographic traits for many species and populations. The ornate box turtle (Terrapene ornata) is a species lacking crucial demographic data. Many populations are isolated in fragmented habitats, especially in the eastern portion of their range. We carried out long-term capture-mark-recapture surveys on two isolated populations in northern Illinois to estimate population vital rates and project population persistence with deterministic stage-based matrix models. Using 34 years of data, we estimated adult female survival = 0.974 (95% CI: 0.946–0.988) and juvenile survival = 0.867 (95% CI: 0.688–0.951) at our most intensively surveyed site. At a second site using 8 years of data, we estimated adult female survival = 0.897 (95% CI: 0.783–0.954) and juvenile survival = 0.844 (95% CI: 0.551–0.960). Despite seemingly high annual survival rates, populations declined under population projections using mean vital rates. Population growth was most sensitive to adult survival, with increasing sensitivity under more pessimistic scenarios. Our results highlight the importance of long-term demographic studies for threatened species and demonstrate protecting adult female ornate box turtles is critical for ensuring populations persist at the northern edge of their distribution.

Read the full paper:

Edmonds, D.,  L. Adamovicz, M. Allender, A. Colton, R. Nyboer, and M. Dreslik. 2023. Evaluating population persistence of ornate box turtles (Terrapene ornata) at the Northeast edge of their distribution. Wildlife Biology 2023:e01183. doi: 10.1002/wlb3.01183

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New paper on timing prescribed fires to avoid Ornate Box Turtle mortality

Ornate Box Turtle photo by D. Edmonds

PhD candidate Devin Edmonds is lead author on a paper published this week in Journal of Wildlife Management. Recognizing the importance of fire for prairie management, Edmonds et al. examined the behavior and physiology of Ornate Box Turtles to predict when turtles would be underground, sheltered from fire.

 

Abstract

Fire is a vital management tool for maintaining prairie ecosystems. Prescribed burns control invasive species, regulate succession, stimulate plant growth, and are a cheap and effective method for removing excess biomass; however, fire can also inadvertently cause wildlife mortality, placing land managers in a challenging situation. Turtles are especially at risk of mortality from fire because of their low mobility and population sensitivity to reductions in adult survival. We studied ornate box turtles (Terrapene ornata) at 3 sites in Illinois, USA, from 2019–2022 to determine the best predictors of above-ground activity so land managers can conduct prescribed burns when turtles are underground. We used turtle shell temperature, air temperature, soil temperature, and precipitation data to develop a predictive model of above-ground activity. The best model for predicting above-ground activity included an interaction between day of year and current air temperature. Earlier in spring and later in fall, above-ground activity is more likely at higher air temperatures compared to later in spring and earlier in fall when the same likelihood of above-ground activity is predicted at lower air temperatures. In spring, we recommend burning in Illinois ornate box turtle habitat before 1 April when air temperature is <10°C and in fall after 1 November when air temperature is <15°C. Above these temperature thresholds, there is a >5% likelihood that turtles in northern populations are above ground.

Read the full paper:

Edmonds, D. A., Bach, E. M., Colton, A. L., Jaquet, I. S., Kessler, E. J., and Dreslik, M. J.. 2023. Avoiding mortality: timing prescribed burns in ornate box turtle habitat. Journal of Wildlife Management e22510. https://doi.org/10.1002/jwmg.22510

Read more from Elizabeth Bach and Devin Edmonds on the Grassland Restoration Network blog: Ornate box turtle emergence

 

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New paper on Alligator Snapping Turtle movement by ARC program leader Ethan Kessler

Translocated Alligator Snapping Turtle with radio transmitter attached

A paper just out this week  in the Journal of Wildlife Management, “Movement behavior and passive dispersal of a reintroduced population of alligator snapping turtles” found that translocated AST behaved similarly to wild populations, and is largely passive. This can have conservation implications as reintroduced animals may be transported downstream by high flows.

 

Abstract

Maladaptive movement behavior is a leading cause of failure for reptile reintroductions, thus characterizing movement for translocated populations is important to project success. From 2014–2016 we radio-tracked 183 immature reintroduced alligator snapping turtles (Macrochelys temminckii) using very high frequency telemetry in a stream in southern Illinois, USA. We assessed environmental, temporal, morphometric, and microhabitat factors influencing movement, including post-release dispersal from reintroduction sites, movement probability, and step length. We used directional statistics to investigate the effects of precipitation and age on directional movement in the stream. Numerous factors influenced active movement, including ambient temperatures, time since release, use of log jams, turtle size, and age. Precipitation had an age-biased effect on movement. Directional analyses suggested that movement was largely passive as turtles were swept downstream with increased discharge. Overall, the behavior of reintroduced alligator snapping turtles was similar to that reported in wild populations. Passive downstream transport has implications for reintroduced and natural populations as a force for unintentional emigration in channelized streams under current conditions and future high flow regimes.

Read the full paper here.

Kessler, Ethan J. and Michael J. Dreslik. 2023. Movement behavior and passive dispersal of a reintroduced population of alligator snapping turtles. Journal of Wildlife Management. https://doi.org/10.1002/jwmg.22511

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Popular article: Discovering the Ornate Box Turtle: A Rare, Remarkable Illinois Reptile

Graduate student Devin Edmonds wrote an article for the August Issue of Outdoor Illinois, showcasing the subject of his M.Sc. thesis research, the Ornate Box Turtle.

Less common than their Eastern Box Turtle relatives, the Ornate Box Turtle is listed as state threatened. Learn more about this “Rare, Remarkable Illinois Reptile.”

Outdoor Illinois – Discovering the Ornate Box Turtle: A Rare, Remarkable Illinois Reptile

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INHS PaCE Lab at Turtle Survival Alliance Symposium

Dr. Dreslik and several lab members are presenting posters and talks in Charleston, South Carolina this week for the Turtle Survival Alliance’s 21st Annual Symposium on the Conservation and Biology of Tortoises and Freshwater Turtles

 

Population structure of the Western Pond Turtle (Actinemys spp.) across twelve military installations in California
Emily Asche, Matthew I. Parry, Thomas S. B. Akre, Robert Lovich, and Michael J. Dreslik
Western Pond Turtle (Actinemys spp.) populations are currently threatened with habitat loss, predation, and shell disease. The synergies among threats have caused severe population declines whereby they are an endangered species in Washington, a sensitive species in Oregon, and a species of special concern in California. It is imperative to investigate their status in California to determine how prevalent threats are and what level of conservation action needs to be taken to avoid declines. We examined the population structure of the Western Pond Turtle populations at twelve military installations across California through sampling in one-week bouts using 50 aquatic traps at one visit per base. We recorded the body size, life stage, and sex of all individuals. Our study is intended to represent a first pass at determining if there are any immediate conservation concerns, such as biases in stage or sex ratios and population size structure.

Detection and occupancy of the Western Pond Turtle (Actinemys spp.)
Matthew I. Parry, Emily Asche, Robert Lovich, Thomas S. B. Akre and Michael J. Dreslik
Low densities, followed by a secretive nature, create challenges for accurately estimating population estimates and site occupancy rates. The Western Pond Turtle (Actinemys spp.) faces range-wide declines and is currently a species of special concern in California. Our project aims to determine their status across 12 military installations using an occupancy/detection framework while attempting to maximize captures during one 50 aquatic trap/four trap night sampling session per installation. Because we sampled areas of known occupancy, we could focus on estimating detection rates. We aim to create an MS Excel tool to determine the detection probabilities while accounting for various environmental and habitat-related covariates.

Survival matters: Comparing the demographic traits of Clemmys and Glyptemys with long-term capture-recapture data
Devin Edmonds, Michael J. Dreslik, Jeffrey E. Lovich, and Carl H. Ernst

Freshwater turtles are one of the most threatened vertebrate groups, with over half of all species at risk of extinction. Overexploitation and habitat loss are the largest threats, with many turtle populations now small, isolated, and needing conservation action to ensure they persist. To enact informed conservation measures and monitor recovery efforts, managers benefit from information about demographic rates like survival and recruitment for highly threatened turtle species. Survival plays a particularly important role in population persistence, considering the life history of most turtle species is characterized by a long lifespan, delayed sexual maturity, and low fecundity. Thus, even small changes in adult annual survival rates can cause otherwise stable populations to decline. We analyzed three historical long-term capture-recapture datasets to estimate annual survival and recruitment for populations of Spotted Turtles (Clemmys guttata), Wood Turtles (Glyptemys insculpta), and Bog Turtles (Glyptemys muhlengerbii) that live in increasingly threatened wetlands and surrounding habitats. All three have ranges characterized by disjunct distributions and often small and isolated populations. Adult sex ratios in turtles can be affected by differences between the sexes in the timing of maturity, rates of mortality, sex-determining mechanism, or differential immigration/emigration. The two Glyptemys species have genetic sex determination while Clemmys has environmental sex determination. This latter distinction could affect each species responses under warming climate scenarios, since Clemmys might be expected to have female-biased populations as global temperatures increase. However, sex-specific differences in survival of Glyptemys species could also occur. Using multi-decadal data, we analyze sex-specific and species-specific survivorship from a site in eastern Pennsylvania where these turtles were sympatric. Our results help inform conservation efforts for three threatened freshwater turtle species and show the strengths of historic long-term data.

Baseline energetic requirements of Ornate Box Turtles (Terrapene ornata)
Andrea L. Colton and Michael J. Dreslik

Increasing ambient temperatures due to climate change may lead to altered behaviors as turtles attempt to regulate internal body temperatures. Increased efforts to maintain temperatures may result in energetic tradeoffs, leading to reduced individual fitness and, thus, population abundance. Estimation of resting metabolic rates for turtles affords calculation of baseline energetic requirements and the potential to predict costs associated with warming landscapes. Using flow-through respirometry, we will determine the resting metabolic rates (RMRs) of adult Ornate Box Turtles (Terrapene ornata) across a temperature gradient to provide information on energetic costs. The baseline estimates will then be used to determine the annual RMR costs on the landscape.

Ranges on the spectrum of recovery: conservation action for the Spotted Turtle and Eastern River Cooter in Illinois
Michael J. Dreslik

Extinction rates in the Anthropocene are significantly higher than background and previous major events. The extinction process can occur when local populations become extirpated, particularly those on the range periphery where habitats are often sub-optimal. Turtles are one of the most critically endangered taxa, with many anthropogenic factors triggering declines. Although jurisdictional boundaries can often complicate conservation, many North American turtles have peripheral populations of conservation concern. Within Illinois, peripheral populations of the Spotted Turtle (Clemmys guttata) and Eastern River Cooter (Pseudemys concinna) are protected as State Endangered; however, their apparent recovery is quite different. I discuss conservation prioritizations, status assessments, and conservation implementation needs for both species in Illinois. Finally, I compare the pathways to recovery for both species.
Conservation Tools and Actions: Oral Thursday PM

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PACE Lab researchers awarded two Competitive State Wildlife Grants

Two projects from the INHS PACE Lab were among the 21 projects funded nationally by the 2021 U.S. Fish and Wildlife Service’s Competitive State Wildlife Grant (C-SWG) program.

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.

musselsThe 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.

 

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2021 Midwest PARC conference

The INHS Population and Community Ecology Lab had four posters at the 2021 Midwest Partners in Amphibian and Reptile Conservation Virtual Conference, October 1-2, 2021.

 

Colton, Andrea L., E. L. Sunnucks, and M. J. Dreslik. Community Structure of Freshwater Turtles in Northeastern Illinois Marshes.

 

 

Edmonds, Devin A., A. Colton, E. Sunnucks, I. Jaquet, and M. J. Dreslik. Timing of prescribed burns to avoid Ornate Box Turtles (Terrapene ornata).

 

Lorenzen, Brock C., A. R. Kuhns, J. A. Crawford, C. A. Phillips, and M. J. Dreslik. Halting the Decline of a Jefferson Salamander (Ambystoma jeffersonianum) population: A Conservation Success Story.

 

Predicted distribution of kirtland's snake in illinoisStewart, Tyler M., A. R. Kuhns, J. A. Crawford, C. A. Phillips, and M. J. Dreslik. Predicted Distribution of Kirtland’s Snake (Clonophis kirtlandii) in Illinois.

Congratulations to M.S. student Tyler Stewart who won the Brodman Student Award for excellence in presenting a poster!
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New paper on habitat restoration impacts on box turtles

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.

Read the paper: Edmonds, D., A.R. Kuhns, and M.J. Dreslik. 2020. Eastern Box Turtle (Terrapene carolina carolina) growth and the impacts of invasive vegetation removal. Herpetological Conservation and Biology 15(3):588–596.