Reptile Conservation and Management I2021-07-21 09:00 - 11:45 |
| Moderator: Henry Mushinsky |
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1. 09:00 IN-PERSON Infection Experiments Indicate Florida Anurans and Lizards Can Serve as Intermediate or Paratenic Hosts for the Invasive Pentastome, Raillietiella Orientalis. Jenna N. Palmisano*, Stetson University; Carson M. Bockoven, Stetson University; Marie V. Domina, Stetson University; Samantha M. McPherson, Stetson University; Heather D.S. Walden, University of Florida; Robert J. Ossiboff, University of Florida; Terence M. Farrell, Stetson University jpalmisano@stetson.edu
Raillietiella orientalis, an endoparasitic crustacean, has now spread throughout much of Florida. This parasite inhabits the respiratory systems of snakes as adults, but the species that serve as intermediate and paratenic hosts are currently unknown. We conducted laboratory infections with insects (Blaberus discoidalis), lizards (Anolis sagrei), anurans (Anaxyrus terrestris, Lithobates sphenocephalus, Osteopilus septentrionalis), and mammals (Mus musculus) to develop an understanding of potential intermediate and paratenic hosts and to determine the fitness consequences of R. orientalis. Lizards and insects, but not anurans and mammals, were readily infected by consuming food contaminated with R. orientaliseggsfrom infected Sistrurus miliarius fecal matter. More than 85% of A. sagrei and L. sphenocephalus, but not mice, were infected following consumption of R. orientalis larvae in roaches. We suspect that the life cycle of R. orientalisin Florida involves a sequence of three hosts. The eggs likely hatch in a coprophagous insect that, after being consumed, infects lizards and anurans, which subsequently infect the definitive hosts (snakes). Comparison with non-exposed control animals revealed no significant impacts on survival or growth in these hosts; species that serve as intermediate or paratenic hosts may not experience major adverse effects from infection. Furthermore, the diversity of species that can act as intermediate or paratenic hosts and the possibility of vehicular rafting by infected roaches and lizards indicate the potential for rapid range expansion and the difficulty of effective intervention. |
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2. 09:15 IN-PERSON The Invasive Pentastome Parasite, Raillietiella orientalis, Pervades the Herpetofauna of Central Florida Habitats. Terence Farrell*, Stetson University; Jenna Palmisano, Stetson University; Alexis Aguilar, Stetson University; Craig Lind, Stockton University; Robert Ossiboff, University of Florida; Heather Walden, University of Florida tfarrell@stetson.edu
Introduced parasites with complex life histories have the potential to dramatically alter ecosystem dynamics, and the rapid spread of R. orientalis may be an emerging example of this phenomena. Experimental infection studies suggest several Florida anurans and lizards can serve as hosts for R. orientalis;however, captive infection may not accurately predict which species serve as hosts in the wild. To determine these natural intermediate and paratenic hosts, we made field collections of lizards and frogs at Lake Woodruff National Wildlife Refuge and a residential area in central Florida. Our dissections indicated seven species of lizards and anurans harbored larval pentastomes. A significantly greater proportion of southern toads and Cuban treefrogs than brown anoles were infected. The intensity of infection varied greatly, ranging from 1-78 larvae in toads and from 1-10 larvae in brown anoles. In field collections of snakes, we found that eight different species were infected with R. orientalis including three novel definitive hosts (Lampropeltis elapsoides, Thamnophis sauritus and Micrurus fulvius). Infected snakes were found in all five habitat types sampled. Large proportions of the sampled pygmy rattlesnakes (20.2%) and black racers (66.7%) were infected by pentastomes. This invasive parasite is now widespread in central Florida and infects a large number of native species in both natural and urbanized habitats. We predict a rapid expansion in the geographic range of R. orientalis given the species it utilizes as intermediate and paratenic hosts, making it a major conservation issue for many snake species in the southeastern United States. |
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3. 09:30 IN-PERSON Testing the Role of Hormone-driven Chemical Signals in Burmese Python Trailing Behavior. M. Rockwell Parker*, James Madison University; Andrea F. Currylow, U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station in Everglades National Park; Lauren A. Nazarian, James Madison University; Isabella M.G. Bukovich, James Madison University; Charlotte J. Robinson, U.S. Geological Survey, Fort Collins Science Center - South Florida Field Station in Everglades National Park; Melia G. Nafus, U.S. Geological Survey, Fort Collins Science Center; Bryan G. Falk, National Park Service; Amy A. Yackel Adams, U.S. Geological Survey, Fort Collins Science Center mrockwellparker@gmail.com
Snakes use chemical signals to communicate many individual qualities using compounds from the skin. Previous studies found that male Burmese pythons (Python bivittatus), a major invasive predator in the Florida’s Greater Everglades Ecosystem, can distinguish between scent trails laid by conspecifics and follow female trails. This behavior has led to “Scout Snake” programs where males are radio-tracked to breeding aggregations, allowing managers to remove all newly discovered pythons. To further develop this idea, we assessed the role of estrogens in activating female chemical signal production in male pythons. Our goal is to determine if developing chemical lures with pheromones is a tractable management target leading to additional removals. Male pythons were implanted with silastic implants containing either estradiol (E2; n=6) or left blank (SHAM; n=6). Wild, opportunistically caught male pythons (n=39) were then tested in a Y-maze to determine if they would follow scent trails left by experimental animals in the maze. Many behaviors were observed during the trials (i.e., head shakes, pauses, turns, head raises). We prioritized behaviors exhibited prior to python’s choice of an arm for analysis, although additional behaviors were observed. Wild males demonstrating more frequent behavior(s) toward E2 scent compared to SHAM scent suggests that chemical feminization occurred, which we will biochemically validate. The main objective is to determine if male pythons could be feminized as an attractant for other males. An ancillary desired outcome is the development of an effective pheromone lure to enhance trap performance and removal efforts in South Florida. |
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4. 09:45 IN-PERSON Effects of Translocation on Brown Treesnake Movement in an Urban Landscape. Abigail Feuka*, Colorado State University, Department of Fish, Wildlife, and Conservation Biology; Melia Nafus, U.S. Geological Survey, Fort Collins Science Center; Amy Yackel Adams, U.S. Geological Survey, Fort Collins Science Center; Larissa Bailey, Colorado State University, Department of Fish, Wildlife, and Conservation Biology; Mevin Hooten, U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit abigail.feuka@colostate.edu
Preventing the spread of invasive Brown Treesnakes (BTS, Boiga irregularis) to other Pacific Islands is a top priority for natural resource managers. BTS were likely transported to Guam following WWII via ship or air cargo. Because the island remains a transportation hub in the Pacific for commercial and military cargo, the risk of BTS translocation (human-assisted transportation) is ever-present. The U.S. Geological Survey BTS Rapid Response Team currently responds to snake sightings on other islands by searching and trapping in areas near the reported snake sighting. The goal of our research is to inform these search efforts by comparing BTS movement following translocation to the movements of resident, non-translocated snakes. We simulated translocation to a port of entry by moving snakes into an urban area on Guam and tracking their daily movements via telemetry from June to September 2018, February to April 2019, and June to September 2019. We compared movements among multiple snakes in four treatment groups: resident forest snakes, resident urban snakes, snakes translocated from forest to urban areas, and snakes translocated from urban areas to novel urban areas (totaling ~35 individuals telemetered snakes per season). These results improve our understanding of BTS movement dynamics, especially for translocated snakes, which will aid Rapid Response search efforts on other islands. |
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5. 10:00 IN-PERSON A Range-Wide Habitat and Connectivity Model for the Federally Threatened Eastern Indigo Snake (Drymarchon couperi). Houston Chandler, The Orianne Society; Christopher Jenkins, The Orianne Society; Javan Bauder*, U.S. Geological Survey jbauder@arizona.edu
Range-wide species conservation efforts are facilitated by spatially explicit estimates of habitat suitability. However, species-environment relationships often vary geographically and models assuming geographically constant relationships may result in misleading inferences. We present the first range-wide habitat suitability and connectivity model for the federally threatened eastern indigo snake (Drymarchon couperi) as a case study illustrating an approach to account for known latitudinal variation in habitat associations. Specifically, we modeled habitat suitability using interactive relationships between minimum winter temperature and several a priori environmental covariates. We found that multi-scale models including interactive effects with winter temperature outperformed single-scale models and models not including interactive effects with winter temperature. Our top-ranked model had suitable range-wide predictive performance and identified numerous large (i.e., ≥ 1,000 ha) potential habitat patches throughout the indigo snake range. Predictive performance was greatest in southern Georgia and northern Florida likely reflecting more restrictive indigo snake habitat associations in these regions. This study illustrates how modeling interactive effects between temperature and environmental covariates can improve the performance of habitat suitability models across geographically varying environmental gradients. Finally, we converted our habitat suitability surface into a resistance surface and used resistance kernels calibrated to observed indigo snake movement distances to create a connectivity surface. Our resistance kernel calibration indicated strongly non-linear relationships between habitat suitability and resistance. Connectivity was high in some parts of the indigo snake’s range and our results could potentially be used to help delineate population units. |
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6. 10:45 VIRTUAL What a Mesh! Risk, Correlates, and Mitigation of Snake Entanglement in Erosion Control Blankets. Christopher Schalk*, Stephen F. Austin State University; Kasey Jobe, Stephen F. Austin State University; Krista Ward, Wichita State University; Sarah Ebert, Stephen F. Austin State University; Nicholas Schiwitz, Stephen F. Austin State University; Cory Adams, United States Forest Service; Daniel Saenz, United States Forest Service schalkc@sfasu.edu
In road construction projects across the United States, erosion control methods (e.g., erosion control blankets [ECBs]), are mandated to stimulate seedbed regeneration and prevent soil loss. Previous reports have suggested that snakes are vulnerable to entanglement in some ECBs. We conducted two entanglement experiments to examine what factors increase a snake’s risk of ECB entanglement. From our first experiment, we found snakes were more likely to become entangled in ECBs that contained fixed-intersection, small-diameter mesh of polypropylene compared to ECBs with larger diameter polypropylene mesh or ECBs that have woven mesh made of natural fibers. Snake body size was also associated with entanglement; for every 1?mm increase in body circumference, the probability of entanglement increased 4%. Our second experiment tested if modification to the installation methods of erosion control blankets affects the likelihood of snake entanglement. This experiment examined snake entanglement in two treatments: 1) exposed erosion control blanket edge (i.e., perimeter) and 2) buried erosion control blanket edge. Snakes were less likely to attempt to pass through the mesh on the buried edge treatment and all entanglements occurred on the exposed edge treatment. These results can help construct a predictive framework to determine those species and individuals that are most vulnerable to entanglement as well as inform natural resource agencies on additional steps that can be taken to select products that pose lower risks to wildlife. |
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7. 11:00 IN-PERSON Conservation Action Through Expert Solicitation for Illinois’ Amphibian and Reptile Species of Greatest Conservation Need. Michael Dreslik*, Illinois Natural History Survey; John Crawford, National Great Rivers Research and Education Center; Christopher Phillips, Illinois Natural History Survey; Andrew Kuhns, Illinois Natural History Survey dreslik@illinois.edu
In 2000, Congress created the State Wildlife Grant program, whereby states maintain Wildlife Action Plans to address unprecedented extirpation rates and population declines of imperiled fauna. The plans identified sensitive species – termed Species of Greatest Conservation Need (SGCN) – and their primary habitats and threats. However, given the number of species listed and no hierarchical priorities, conservation action has been haphazard and limited. Therefore, we focused on the conservation needs of amphibian and reptile SGCNs in Illinois through focused expert solicitation to ascertain: 1) our current knowledge base; 2) perceived threats; 3) actionable items and synergies. The main goal of our work was to provide a unified course of conservation action. |
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8. 11:15 VIRTUAL Human dimensions in reptilian conservation in the National Chambal Sanctuary, India. RJ Rao*, Barkatullah University; Rajesh Gurjwar, Jiwaji University; Yogesh Singh, Jiwaji University rjrao09@gmail.com
India has adopted Ex-situ and In-situ conservation measures to conserve wildlife species that have been identified as threatened and endangered in suitable locations.The National Chambal Sanctuary, declared on the Chambal River in Gangetic River system in India, contains the largest contiguous and most viable breeding populations of the critically endangered Gharial (Gavialis gangeticus). The aquatic reptilian fauna is very rich in the sanctuary consisting of Indian mugger (Crocodylus palustris) and seven species of freshwater turtles. Human wildlife conflict was recorded in the National Chambal Sanctuary. Threats to the reptiles in the Chambal River has been reached to an unfavourable level due to the excessive expansion of human populations and human-induced activities. Agriculture, sand mining, stone mining, fishing, livestock grazing were the major key issues along the Chambal River. These activities adversely affect the habitat of wildlife. Major socio-economic issues in the sanctuary were poverty and illiteracy. These issues further give rise to anti-social elements. People are largely dependent on the river as a source of water. Sand-mining along the river causes considerable disturbance to aquatic reptiles, particularly in the breeding habitats.Large number of locals depend on the natural resource so there is a need to restructure the wildlife conservation policies to accommodate the people's interest and dependency on the ecosystems. To control human wildlife conflict mitigation measures like conflict reduction and benefit generation schemes, training programs, education of locals on wildlife ecology, conflict avoidance measures and wildlife-specific tourism potential have been suggested. |
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9. 11:30 VIRTUAL Feeling Rattled: Linking Attitudes and Habitat Features to Patterns of Snake Occurrence in Urban Landscapes. Annika Enloe*, Arizona State University Polytechnic; Heather Bateman, Arizona State University Polytechnic amenloe@asu.edu
Understanding how wildlife is adapting to urban environments is critical as urbanization contributes to habitat change and fragmentation globally. Patterns of human-wildlife interactions (HWI) can be informative when trying to ascertain information about urban wildlife and community science databases are becoming more and more commonly used in ecological research. In Phoenix, Arizona, HWI commonly involves reptiles including venomous and nonvenomous snakes. Rattlesnake Solutions, LLC, a local business, removes and relocates snakes from homes and businesses in the Phoenix area and has provided me with records of snake removals. I will use this expansive, spatial dataset to compare occurrence patterns and habitat preference among snake taxa in urban Phoenix. Along with ecological predictors such as habitat features, social data will be utilized within analyses to model patterns of human-snake interaction through a socioecological lens. In addition to a survey distributed to clients of Rattlesnake Solutions, LLC, snake removals overlap spatially and temporally with distribution of the Phoenix Area Social Survey (PASS) which provides an opportunity to link ecological and social data regarding attitudes towards snakes in urban Phoenix and the surrounding area. |
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10. 11:35 VIRTUAL Conservation Assessment of the Florida Scrub lizard: An Endemic Species Response to Climate Change. Alison Gainsbury*, University of South Florida St. Petersburg Campus alisong@usf.edu
Climate change is impacting species globally, with many populations declining at an accelerated rate toward extinction. Ectothermic species are particularly vulnerable given their reproductive success is linked to environmental temperatures. Studies on the effect of temperature on reproductive success in oviparous squamates have focused mostly on nest temperatures, after eggs are deposited. However, in some species gravid females are known to thermoregulate differently than other adults to increase reproductive success. It is essential to understand what influences the thermal biology of breeding adults in a population to implement targeted conservation strategies. The Florida scrub lizard, Sceloporus woodi,is an endemic species listed as near-threatened due to decreasing populations. This study is the first to document the thermal biology of these breeding adults in relation to size, sex, and reproductive status. Full linear mixed-effects models were used to test the influence of size, sex, and reproductive status on the thermal biology of S. woodi. Interestingly, reproductive status influenced thermal biology of females during the breeding season, with gravid females maintaining lower body temperatures compared to nongravid females. These results indicate the population viability of this endemic species is potentially linked to the different thermoregulatory requirements of gravid females as compared to other adults. Lower body temperatures of gravid females have disconcerting conservation implications in the face of climate warming. Future studies focusing on gravid females are warranted to attain effective biodiversity conservation strategies mitigating the impacts of climate warming. |
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11. 11:40 VIRTUAL CANCELLED - Humans likely influence spread of an invasive skink on a Pacific island. Levi Gray*, Fort Collins Science Center, U.S. Geological Survey; Melia Nafus, Fort Collins Science Center, U.S. Geological Survey; Gordon Rodda, Fort Collins Science Center, U.S. Geological Survey; Scott Vogt, United States Department of Defense, Andersen Air Force Base; Robert Reed, Pacific Island Ecosystems Research Center lgray@usgs.gov
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