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    Amphibian Conservation and Ecology I

    2021-07-22   13:45 - 15:45

    Moderator: Muhammad Rais

    1.  13:45  IN-PERSON    Boreal Toads of the Grand Mesa National Forest. Royanna Crawford*, Colorado Mesa University; Jenn Logan, Colorado Parks & Wildlife; Denita Weeks, Colorado Mesa University

    Boreal Toad (Anaxyrus boreas) populations have declined across Colorado due to a fungal infection caused by Batrachochytrium dendrobatidis (Bd).Historically, Boreal Toads were common on the Grand Mesa National Forest, but went undetected in surveys for 25 years until Colorado Parks & Wildlife crews discovered a population in the Buzzard Creek drainage in 2002. This population is infected with Bd but remains stable and reproductively active. In 2020, we assisted Colorado Parks & Wildlife with monitoring of that population and surveying nearby sites for translocation suitability. A translocation of tadpoles was completed upstream of the Buzzard Creek population and late season surveys revealed that they completed metamorphosis. In 2021, surveys continue on the Buzzard Creek population, the 2020 translocated population, and additional sites for future translocations.

    2.  14:00  VIRTUAL    Host Species is Linked to Pathogen Genotype for the Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) in the USA. Allison Byrne*, Smithsonian Conservation Biology Institute; Anthony Waddle, University of Melbourne; Jef Jaeger, University of Nevada, Las Vegas; Jamie Voyles, University of Nevada, Reno; Corinne Richards-Zawacki, University of Pittsburgh; Bree Rosenblum, University of California, Berkeley

    The amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has caused devastating declines in amphibian communities around the world. Specifically, a single lineage of this pathogen – termed the global panzootic lineage (Bd-GPL) – has been linked to almost all deadly disease outbreaks. The origin of Bd-GPL and the fine-scale transmission dynamics of this lineage have remained a mystery, especially in the United States where Bd-GPL is widespread, but disease outbreaks are sporadic. Here, we use Bd genetic data collected throughout the United States from non-invasive amphibian skin swab samples to investigate what ecological and geographic factors influence Bd genetic patterns. We highlight two case studies (Pennsylvania & Nevada) where Bd genotypes are highly correlated with host species identity. Specifically, in some localities Bullfrogs (Rana catesbeiana) are host to distinct Bd-GPL lineages as compared to other sympatric amphibian species. Overall, this dataset reveals a previously unknown association of Bd genotype with host species identity and has far-reaching implications for tracing past Bd spread and preventing future outbreaks.

    3.  14:15  VIRTUAL    Are Pesticides Problematic? Carryover effects of aquatic Imidacloprid exposure on the wood frog (Rana sylvatica). Cassandra Thompson*, Ohio University; Megan Sweeney, Ohio University; Viorel Popescu, Ohio University

    Neonicotinoids are a common class of systemic pesticides used in the US that often have sublethal effects on amphibian growth, development, and behavior. Imidacloprid, a neonicotinoid pesticide, is extensively applied throughout the eastern US to control the spread of invasive hemlock wooly adelgids (Adelges tsugae), without fully understanding the impacts on the aquatic and terrestrial stages of pool-breeding amphibians and how it may interact with additional aquatic stressors. As hydroperiod (how fast a pond dries) varies widely across vernal pools and wetlands and can have direct negative impacts on amphibian development and terrestrial fitness, we sought to understand the combined effects of these stressors on larval development and survival and juvenile locomotor performance and behavior of the wood frog (Rana sylvatica). We manipulated hydroperiod length (nondrying vs drying) in 1000 liter cattletank mesocosms with and without Imidacloprid exposure (10 ppb) for a total of four aquatic treatments. While we did not find any significant differences in morphology (mass/SVL) of metamorphs from the four treatments, larval survival to metamorphosis was lowest in the pesticide x hydroperiod treatment. Juveniles from pesticide treatments performed significantly better during initial endurance trials, however, after exposure to a low concentration of the pesticide, individuals from pesticide treatments experienced greater declines in performance compared to non-pesticide treatments. The biological and physiological insights from this work can be used to better understand the impacts multiple aquatic stressors have on amphibian larval development and help to better the risks of the application and use of such systemic pesticides.

    4.  14:30  VIRTUAL    Assessing Efficacy of Translocation as a Conservation Strategy for Wild Eastern Hellbenders in Tennessee. Bradley Nissen*, Tennessee State University; Emilly Nolan, Tennessee State University; William Sutton, Tennessee State University; Michael Freake, Lee University; Rebecca Hardman, Univeristy of Tennessee

    The fully aquaticEastern Hellbender salamander (Cryptobranchus alleganiensis alleganiensis)issensitive to disturbances toaquatic environmentsandoftenconsidered a bioindicator.Due to population declinesand habitat fragmentationthroughout its range,thehellbenderis a strong candidate for translocation in Tennessee. Weevaluatedtheshort-term successof translocation onwildhellbenders bycomparingthespatial ecologyof individualspre- and post-translocationusingradio-telemetry. Westudiedthehome range sizes,movementsand multi-scale habitat use of individuals(N =27)in two sustainable populations(SS1&SS2)for one yearandthensubsequentlycollected similar data froma portion of theseindividuals (N =17)thatwere translocated(May-July 2019)into two nearby streams(TS1 & TS2)with declining populations.Wecollected1,571location data points(869pre-translocationand715post-translocation)from ourfour study sites.Survivalratesoftranslocated individualsincreasedwhen moved fromSS1toTS1(80% to 100%), while theydecreasedwhen moved fromSS2toTS2(76% to33%).Home range sizes increased from pre-translocation rates at both sites, but responses depended heavily upon physical characteristics of the release sites.Anobservedincreaseinimportance of boulder densities on hellbender resource selectionaftertranslocation implies that large boulder clusters could serve as important cues for “suitable habitat” as hellbenders are assessingnew environments.Wefound that translocations of wild hellbenders could be beneficial for regions wheresuitablehabitat exists without healthy hellbender populations.This studyinformsmanagers about the potential for translocation as ahellbenderconservation strategy.

    5.  14:45  IN-PERSON    Population Estimation and Movement Patterns of Endemic Frogs in Forested Montane Freshwater Wetlands of Pakistan: A Baseline Study. Muhammad Rais*, PMAS-Arid Agriculture University Rawalpindi; Arooj Batool, PMAS-Arid Agriculture University Rawalpindi; Jamal Ahmed, PMAS-Arid Agriculture University Rawalpindi; Kirsty Kyle, North West University; Waseem Ahmed, PMAS-Arid Agriculture University Rawalpindi

    We document a baseline study to estimate the population of Nanorana vicina (Murree Hills Frog) and Allopaa hazarensis (Hazara Frog) also detailing their daily and seasonal movements (pre-breeding and breeding-post-breeding). From this we estimated 185 Murree Hills Frogs and 90 Hazara Frogs within the study area (0.79 ha). The daily and seasonal movement data showed that the two species moved either between neighboring ponds or remained in an array of smaller ponds (within an area of 120 m2) along the stream bank. About 75% of movements were < 29.5 m in Nanorana vicina and < 50.87 m in Allopaa hazarensisduring pre-breeding season while < 41.5 m in Nanorana vicina and < 81 m in Allopaa hazarensisduring breeding-post-breeding season. We suggest inclusion of amphibian habitat requirements, such as creating artificial wetlands and ensuring stream connectivity in urban planning and development projects in the area, to prevent the local extinction of the endemic species. In the future, more robust and long-term studies, encompassing more streams situated within a wider area, would help clarify dispersal, colonization, metapopulation structure, and dynamics of these endemic frogs of the forested montane streams in the Himalayan Foothills.

    6.  15:00  IN-PERSON    Larger animals that are more resilient to drought also require more good years to get there. Thomas Luhring*, Wichita State University; Lyndsie Wszola, University of Nebraska; Grant Connette, Working Land and Seascapes, Conservation Commons, Smithsonian Institution; Christopher Schalk, Arthur Temple College of Forestry and Agriculture, Stephen F. Austin University

    Many aquatic organisms are experiencing increasingly severe droughts with shorter periods between them. Organisms are thus faced with fewer and poorer quality inter-drought years to prepare for increasingly severe droughts. Animals that estivate to survive drought events rely on endogenous energy reserves to persist. Here, we assess the impact of inter-drought year quality (represented by the Palmer Drought Severity Index) and sex on the growth (length), mass, and estivation potential (dependent on mass) of a species (Greater Siren, Siren lacertina) with a positive relationship between size and drought survivorship. We calculate growth rates (length) of S. lacertina based on data spanning 11 years of one of the most severe drought local minima in the Southeastern United States in 50 years. We use growth rates to create age-class specific estimates of length, mass, and estivation potential given sex, site-specific length-mass relationships, and mass-dependent aestivation potential.

    7.  15:15  VIRTUAL    Perils, precipitation, and pollywogs: how extreme weather events impact the effect of tadpoles on their ecosystem. Jessica Ford*, Redpath Museum, McGill University; David Green, Redpath Museum, McGill University

    Extreme weather events, such as intense storms and increased amounts of precipitation, are becoming more common with changing climatic conditions. With this in mind, it is important to consider how extreme weather events, or even just odd years, can impact our assessment of the ecological role of a species. Amphibian larvae can play various roles in an ecosystem, influencing sedimentation rates, nutrient cycling, algal biomass, and zooplankton community composition. However, the effect of amphibian larvae, or the apparent effect, can shift in the presence of predators, competitors, and changing environmental conditions. We assessed the net effects of toad tadpoles in experimental mesocosms in 2018 and 2019. While the system and location we used were the same, the environmental conditions differed, with Long Point, Ontario receiving record amounts of precipitation in 2019. The apparent net effects of tadpoles differed dramatically between 2018 and 2019. While the effects of tadpole presence were apparent in 2018, as seen by a more consistent concentration of phosphorus through time, lower algal biomass, and higher zooplankton diversity, no such effects were detected in 2019. It is possible that the intense rainfall diluted the effects of the tadpoles in the mesocosms, or that the tadpoles shifted their behaviour in response to the extreme rainfall. This heeds a warning when assessing the ecological role of a species, as it is possible that the true effect of the species will be diluted out in extreme rainfall events, leading to an incorrect assessment of that species’ importance in the ecosystem.

    8.  15:30  IN-PERSON    Life-history of the Rare Patch-nosed Salamander: Revisited. Tyler Brock*, Southeastern Louisiana University; Christopher Beachy, Southeastern Louisiana University

    The Patch-nosed Salamander (Urspelerpes brucei) is a miniaturized lungless salamander that is nearly as enigmatic today as it was prior to its description in 2009. Due to its rarity, there is little information regarding the life-history biology of Urspelerpes, and this lack of knowledge could negatively impact future conservation of the species. Here we looked to confirm the age at metamorphosis in this taxon by using both size-distribution plots and skeletochronology methods. In conjunction with this, we tracked reproductive condition across all dissected individualsin order to confirm age at sexual maturation. We found that Urspelerpes reaches both metamorphosis and sexual maturity during its third year of life, with the onset of gonadal development only slightly preceding that of metamorphosis. These results represent crucial progress in rectifying the aforementioned data deficiency of this unique species, and they demonstrate that vital biological and conservation-relevant information can be obtained for rare species in ways that minimize the sacrifice of animals.

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