Tag: Snakes

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New paper on Timber Rattlesnake hibernacula

Timber Rattlesnake at hibernacula

PhD candidate Andrew Jesper has a new paper out today on determining suitable hibernacula for the state threatened Timber Rattlesnake. The initial habitat suitability model was developed based on known hibernacula across the state of Illinois. The model was refined over a series of surveys based on the model and updating the model based on information from the surveys. Habitat suitability models inform land conservation decisions, enabling prioritization of areas most likely to support suitable hibernacula.

ABSTRACT: The dependency on hibernacula for extended periods presents terrestrial reptiles with the challenge of locating thermally adequate hibernacula each winter. Defining the habitat characteristics of hibernacula is crucial for understanding the overwintering requirements and distributions of hibernacula-dependent reptiles, alongside identifying habitats which warrant special conservation concern. Our objectives were to identify the overwintering habitat characteristics of the imperiled timber rattlesnake Crotalus horridus in Illinois, USA, and to determine the distribution of likely hibernacula habitats throughout the state. Due to the initial sparsity of hibernacula records in Illinois, we adopted an iterative habitat suitability modeling process consisting of 3 distinct rounds of Maxent construction and revision. Each round was informed with updated information from model-guided surveys or by building rapport with in-state naturalists and researchers who knew of additional hibernacula locations. We created our final model using 36 hibernacula and identified slope angle (indicative of rock outcrops and shallow soils), topographical position index, forest patch area, and aspect (decomposed into 2 linearized variables: southness and eastness) as important drivers of C. horridus hibernacula habitat in Illinois. Together, the 5 variables and site surveys suggest the suitable overwintering habitat for C. horridus in Illinois is located on south- to southwest-facing outcrops on upper slopes and ridges of larger forest patches. Such habitat is distributed primarily in southern Illinois and throughout the Mississippi River and Illinois River border counties. Our study adds to the current understanding of the species’ overwintering requirements and provides a foundation for future ecological studies, management, and survey efforts throughout Illinois.

Read the full paper in: Jesper, A. C., S.A. Eckert, S.R. Ballard, J.A. Crawford, and M.J. Dreslik. 2024. Distribution and drivers of critical hibernacula for the timber rattlesnake Crotalus horridus in Illinois, USA. Endangered Species Research Volume 53, page 467

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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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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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Massasauga hibernacula at Carlyle Lake are genetically distinct units

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.

Read the paper at PLOS One

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

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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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    PaCE Lab at the Illinois State Fair

    Smokey Bear using snake tongs

    Members of the PaCE Lab exhibited in Conservation World at the 2019 Illinois State Fair, providing information and education to over 500 visitors. In addition to displays about the research being done by the group, visitors were able to try their hand at using actual field equipment used by scientists in their daily work.

    The Illinois Bat Conservation Program had a mist net deployed where visitors could untangle, identify, and measure bats, all while wearing leather gloves.

    The Amphibian and Reptile Conservation group had snake tongs, hooks, calipers, and radio telemetry equipment available for visitors to try to wrangle snakes into a snake bag, measure turtles, or track a hidden turtle.

    Other activities included Build-a-Bug, where people can assemble the arthropod of their dreams (or nightmares) from a variety of general and specialized appendages, Wheel of Migration, about the risks migratory birds face, and locating PIT-tagged animals.

    Smokey Bear using snake tongs
    Gray Treefrog picked the right tent to visit
    Wheel of Migration
    Build a Bug
    Vin Vasive wrangling a snake with a hook
    Build-a-Bug
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    Midwest Fish and Wildlife Meeting

    UBAP herpetologist Sarah Baker co-organized a symposium “Advances and Challenges in Amphibian and Reptile Conservation and Management” and presented “Impact of Snake Fungal Disease on Population Viability” at the 78th Midwest Fish and Wildlife Conference in Milwaukee, WI. Jan 28-31.

    Student Kelsey Low presented a poster on “Ranavirus Effects on Body Condition and Growth of Developing Amphibians in Created Wetlands”

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    UBAP staff present at Biology of the Snakes Conference

    Members of the Urban Biotic Assessment Program, Michael J. Dreslik and Sarah J. Baker, recently attended and presented at the Biology of the Snakes 2017 Conference in Rodeo New Mexico. They gave two oral and two poster presentations.

    Oral Presentations
    Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Spatial ecology of the Timber Rattlesnake (Crotalus horridus) from the mid-Atlantic coastal plain.

    Dreslik, M. J., J. A. Crawford, S. J. Baker, W. E. Peterman, and C. A. Phillips. Detection probability and capture yield of an imperiled species.

     

    Poster Presentations
    Baker, S. J., M. J. Dreslik, C. A. Phillips, and M. C. Allender. Impact of snake fungal disease on population viability.

    Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Factors affecting the movements of Timber Rattlesnakes (Crotalus horridus) from the mid-Atlantic coastal plain. View Poster

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    UBAP staff present at the Joint Meeting of Ichtyhologists and Herpetologist

    Members of the Illinois Natural History Survey’s Urban Biotic Assessment Program and Herpetology Lab recently attended the Joint Meeting of American Society of Ichthyologists and Herpetologists, Society for the Study of Amphibians and Reptiles, and Herpetologists’ League in Austin, Texas from 12 July to 16 July 2017. They presented on a variety of topics from rattlesnakes to darters and from wildlife disease to community changes. The combined topics for presentations and posters were:

     

    Presentations:

    Baker, S. J., M. J. Dreslik, C. A. Phillips, and M. C. Allender. Impact of snake fungal disease on population viability.

    Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Factors affecting the movements of Timber Rattlesnakes (Crotalus horridus) from the mid-Atlantic coastal plain.

    Low, K. M., M. C. Allender, C. A. Phillips, and S. J. Kimble. A ranavirus-associated mass mortality event in an Illinois amphibian community.

    Ross, J. P., C. Y. Feng, and M. J. Dreslik. Evaluating reptile and amphibian passage gates using remote camera traps.

    Sites, A. J., J. L. Sherwood, J. S. Tiemann, and M. J. Dreslik. Assessing the distribution of Iowa Darters (Etheostoma exile) in streams of northern Illinois.

     

    Posters:

    Baker, S. J., and M. C. Allender. Comparison of testing methods for snake fungal disease.

    Dreslik, M. J., C. E. Petersen, S. M. Goetz, J. D. Kleopfer, and A. H. Savitzky. Spatial ecology of the Timber Rattlesnake (Crotalus horridus) from the mid-Atlantic coastal plain. View Poster

    Sherwood, J. L., and J. A. Stein. Habitat and fish community changes in Champaign County, IL over the past 100 years.