PACE Lab News

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New paper on more efficiently detecting Kirtland’s Snake

kirtland's snake
Kirtland’s Snake

Recent PaCE Lab graduate Tyler Stewart published a paper on his M.Sc. work creating a species distribution model for the rare and cryptic Kirtland’s Snake, Clonophis kirtlandii. He found that surveys Mid-May to early July when there was high cloud cover, moderate air temperature, and low relative humidity enhanced the detection probability of this species.

 

Abstract

Snakes are difficult to study due to their cryptic coloration, minimal movements, and use of inaccessible habitats. Although well‐timed surveys during a species’ active season can result in higher detection rates and conserve survey resources (i.e., time and money), survey effort may not ensure the detection of rare and cryptic species. Thus, in such instances, a strategic species‐ specific sampling design is needed. The Kirtland’s snake (Clonophis kirtlandii) is a rare, cryptic species assumed to be experiencing range‐wide declines. Naturalists have noted the disappearance of Kirtland’s snakes from various habitats since the early 1970s. The primary objective of our study was to determine detection of Kirtland’s snakes and the environmental and temporal factors influencing detection. We calculated the effort needed to detect individuals at sites by estimating detection probabilities of 3 known Kirtland’s snake populations in Illinois from 2019 to 2021. Based on 77 Kirtland’s snake detections over 226 site visits (34.1%) across 3 study sites, we found that high cloud cover, moderate air temperature, and low relative humidity enhanced the detection probability of this species. The middle of May to the beginning of July was the best time to conduct surveys when detection rates were highest. As our results suggested, it is imperative to establish strategic monitoring programs maximizing conservation resources to document populations for conservation action and range shifts for species of conservation concern, such as Kirtland’s snakes.

Stewart, T. A., A.R. Kuhns, C.A. Phillips, J.A. Crawford, and M.J. Dreslik.  2023. Estimating the effort required to detect Kirtland’s snakes (Clonophis kirtlandii). Wildlife Society Bulletin. http://doi.org/10.1002/wsb.1498

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UBAP lead and ornithologist Anastasia Rahlin presents on railway ecology

UBAP program lead and ornithologist Anastasia Rahlin was invited to present at the 2023 Railroad Environmental Conference (RREC). Her talk, titled “Railway Ecology: Using Railway Corridors to Restore Native Habitats and Preserve Biodiversity,” discussed the emerging field and made recommendations for future research.

There are 48,000 hectares of railway right of way in Illinois, 774,000 hectares in the US, and 4,122,000 hectares globally which could be managed for wildlife conservation.

Rahlin discussed where research efforts should be focused”

Collisions and wildlife crossings

    • Continue fencing high-speed railways
    • Create wildlife passages for low-vagility species

Habitat Restoration

    • Maintain native plant diversity in verges
    • Focus on restoring grasslands – appear more susceptible to invasive species

Species monitoring and management

    • Expand focus from large mammals
    • Standardized, repeated surveys needed to establish baselines
    • Need for robust occupancy and abundance models
    • Multi-year monitoring before and after construction/expansions
    • Investigate life history parameters for well-studied species
    • Adaptive management framework

Future Research

    • Before-After-Control-Impact (BACI) designs
    • Establish experimental vegetation plots along verges
    • Take advantage of novel technology
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INHS PaCE Lab members present at The Wildlife Society meeting

Two members of the INHS PaCE Lab presented at The Wildlife Society annual conference November 5-9 in Louisville, KY.

scientific poster about point of care device to monitor birdsUBAP program leader and ornithologist Anastasia Rahlin presented a poster “Using Point of Care devices to assess Marsh and Sedge Wren food limitation”

Abstract:
Food limitation affects wildlife health and survival, may stem from differences in body condition or habitat quality between sites, and may be exacerbated by extreme weather events. Blood metabolites have previously been used as a food limitation index in birds. To assess changes in blood metabolites in marsh and sedge wrens, we used Point of Care devices to measure blood glucose, ketones, and triglyceride levels as short and long-term food limitation indices. We collected blood samples from wrens in May-August 2022 and 2023 in two Illinois DNR state parks and one dedicated conservation area in the Chicagoland Wilderness region over the duration of the breeding season. Our data indicate short-term food limitation may increase as the breeding season progresses for both Marsh and Sedge Wrens. Ongoing modeling will test whether body condition (age, fat and muscle scores), habitat quality (wetland extent and composition), or extreme weather (drought or flooding) best predicts glucose, ketone, and triglyceride levels over the course of the breeding season. Our findings will provide insights into physiological responses of sedge and marsh wrens to food limitations, and highlight the utility of using POC devices to rapidly measure blood metabolites in the field with minimal impacts to study species. An additional goal of this research is to use blood metabolite data to identify high-quality sites for migratory birds; our data will be used to evaluate the effectiveness of conservation areas at providing high-quality habitat. This work will inform wetland and wet meadow management strategies for migratory birds.

scientific poster about pond breeding amphibian egg massesARC program leader Ethan Kessler presented a poster “Reproductive output of forested ephemeral wetland-dependent amphibians across a modified landscape”

 

Abstract:
Forested ephemeral wetlands (FEW) support diverse communities of habitat specialist species across the eastern United States, including wetland-breeding amphibians (WBA). Due to their reliance upon FEW for breeding habitat, the location of FEW on the landscape influences population dynamics and distribution of WBA. Generally, FEW are difficult to detect due to their small size and position under the canopy, however, recent technological advances provide the ability to remotely detect FEW with great accuracy. Improved FEW detection methods enable a better understanding of how FEW characteristics and distribution influence WBA presence and abundance. We counted egg masses of two widespread WBA species, Spotted Salamanders and Wood Frogs, at 231 FEW on public lands in southern Illinois using a double observer methodology from 2020–2023. We then used local and landscape characteristics to predict egg mass abundance for each species. We found egg mass counts were highly correlated between observers for each species, but the presence and abundance of egg masses were not highly correlated between the two species. For Spotted Salamanders, we found a positive effect of wetland size on egg mass abundance but found no effect of canopy cover within a 200 m buffer. Conversely, for Wood Frogs we found no effect of wetland size, but egg mass abundance was positively associated with canopy cover within 200 m of FEW. Results from this study will provide a foundation for the estimation of WBA across broad geographic scales using discrete maps of FEW.

 

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New paper on Baron’s mantella frog, co-authored by Devin Edmonds

frog on moss
Mantella baroni photo by Devin Edmonds

INHS PaCE Lab PhD candidate Devin Edmonds co-authored a recent paper on habitat features of Baron’s Mantella Frog. Tantely Rasoarimanana (Université d’Antananarivo) and Olivier Marquis (Paris Zoo) led the collaboration with the NGO Man and the Environment. The study aimed to identify what microhabitat features explain the presence of Baron’s mantella frog (Mantella baroni) and also estimate their population sizes in Vohimana Reserve, eastern Madagascar. We found that leaf litter depth and the number of small trees in a quadrat were important habitat features; deeper leaf litter and fewer small trees explained if M. baroni was present.

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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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New Timber Rattlesnake publication by PhD candidate Andrew Jesper

Trailcam image of Timber Rattlesnake at den opening

Abstract: Many temperate reptiles survive winter by using subterranean refugia until external conditions become suitable for activity. Determining when to emerge from refugia relies on the ability to interpret when above-ground environmental conditions are survivable. If temperate reptiles rely on specific environmental cues such as temperature to initiate emergence, we should expect emergence phenologies to be predictable using local climatic data. However, specific predictors of emergence for many temperate reptiles, including the Timber Rattlesnake (Crotalus horridus), remain unclear, limiting our understanding of their overwintering phenology and restricting effective conservation and management. Our objectives were to identify environmental cues of spring emergence for C. horridus in Illinois to determine the species’ emergence phenology, and to examine the applicability of identified cues in predicting emergence phenology across the species’ range. We used wildlife cameras and weather station-derived environmental data to observe and predict the daily surface presence of C. horridus throughout the late winter and early spring at communal refugia in west-central and northern Illinois. The most parsimonious model for predicting surface presence included the additive effects of maximum daily temperature, accumulated degree days, and latitude. With a notable exception in the southeastern U.S., the model accurately predicted the average emergence day for eight other populations range wide, emphasizing the importance of temperature in influencing the phenological plasticity observed across the species’ range. The apparent broad applicability of the model to other populations suggests it can be a valuable tool in predicting spring emergence phenology. Our results provide a foundation for further ecological enquiries and improved management and conservation strategies.

 

Read the paper at:

Jesper AC, Eckert SA, Bielema BJ, Ballard SR, Dreslik MJ. 2023. Phenology and predictors of spring emergence for the Timber Rattlesnake (Crotalus horridus) PeerJ 11:e16044 https://doi.org/10.7717/peerj.16044

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New publication from aquatic ecologist Hugo Ruellen

INHS PaCE Lab’s aquatic ecologist, Hugo Ruellen is lead author on a recent publication stemming from his M.Sc. research on freshwater mussels: “Predicting suitable habitat for surrogate species of critically imperiled freshwater mussels to aid in translocations.”

Mussel translocations have been used to mitigate the impacts of in-stream construction projects, including bridge replacements. This work developed a model to predict suitable habitat for mussels. “Knowing where and how much suitable habitat is present in rivers is essential to the conservation and long-term persistence of endangered freshwater mussel species, and habitat suitability models such as these are important tools for achieving these goals.”

 

Ruellan, Hugo Y., Kirk W. Stodola, Alison P. Stodola, and Jeremy S. Tiemann. 2023. Predicting suitable habitat for surrogate species of critically imperiled freshwater mussels to aid in translocations. Freshwater Science 42(3): 296-314. https://doi.org/10.1086/726740

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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