Session 23: ASIH Stoye Conservation II (first 5)/ Stoye Ecology and Ethology II (last 3)Room: Room 206C2022-07-29 10:00 - 11:45 |
| Moderator: Peter Lindeman |
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1. 10:00 Small is Big: A New Conservation Paradigm for Amphibians. Emma Steigerwald*, Museum of Vertebrate Zoology, UC Berkeley; Julianne Oshiro, UC Berkeley; Julia Chen, UC Berkeley; Alessandro Catenazzi, Department of Biological Sciences, Florida International University; Michelle Koo, Museum of Vertebrate Zoology, UC Berkeley; Vance Vredenburg, Department of Biology, San Francisco State University emma_steigerwald@berkeley.edu
How might we maximize the conservation value of additions to our protected area (PA) network, given international commitments to protect 30% of Earth by 2030? Even when PA design considers biodiversity conservation, a shortcoming of our current network is that design is generally guided by principles derived from considering only megafauna. One repercussion of such taxonomic bias is that biodiversity-motivated PA design has heretofore underestimated the conservation value of small PAs. Using databases from AmphibiaWeb, the World Database of Protected Areas, and the IUCN, we explore how existing paradigms about optimal PA size shift upon considering a traditionally neglected taxon like amphibians. We demonstrate that amphibian ranges tend to be smaller than those of other terrestrial vertebrates, even when considering only endangered species. Although many endangered amphibians could have their entire distribution subsumed by the creation of small PAs, we show that endangered species are overrepresented among amphibians whose ranges do not overlap with existing PAs. We indicate that even the smallest PAs (<1km2) can have amphibian species richnesses rivalling those of the largest global PAs and show, using the existing PA network, that we can better sample amphibian biodiversity with smaller PAs if they are strategically placed. Unfortunately, the rate of PA declarations has slowed since 2010, so we illustrate global opportunities to capture many entirely unprotected amphibians through small PA creation. We contend that incorporating the needs of neglected taxa into PA design illuminates politically and economically tractable potential PAs with immense added value for biodiversity conservation. |
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2. 10:15 An integrative synthesis to global amphibian conservation priorities. Sky Button*, Washington State University; Amaël Borzée, Nanjing Forestry University sky.button@wsu.edu
Human activities are driving many species to the brink of extinction, and the current distribution of protected areas only weakly alleviates pressure on threatened species. This discrepancy reflects the presence of protected areas on lands available instead of the ecological, evolutionary, or conservation values of species present. Habitat loss consequently continues to impact threatened species, as illustrated by geographic patterns of biodiversity loss for amphibians. Given the need to better align the boundaries of protected areas with at-risk biodiversity, we assessed the importance of various factors for identifying global and biome-level conservation priority areas, specifically for amphibians. We identified, mapped, and ranked areas of critical conservation importance for all amphibian species on earth using a new integrative tool that scores the urgency of conserving each species and location based on a combination of species characteristics and ecoregion-level human impacts. Our integrative approach is novel in that it accounts for likely threats to Data Deficient species, considers the irreplaceability of unique species that are phylogenetically isolated, and addresses the localized conservation implications of species endemicity and projected future human impacts to an ecoregion. For comparison, we also mapped and ranked amphibian biodiversity using species richness and an Evolutionarily Distinct and Globally Endangered (EDGE) score proxy. Our integrative approach predicted key regions for amphibian conservation that were not apparent when using a simple species richness or EDGE score proxy-based approach. This approach provides an avenue for avoiding common pitfalls of more simplistic species richness-based approaches for conservation and protected area planning. |
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3. 10:30 Abnormalities in the At-Risk Gopher Frog (Lithobates capito): What We Know and Where We’re Going. Adam McFall*, Savannah River Ecology Laboratory, University of Georgia; Kiersten Nelson, Savannah River Ecology Laboratory, University of Georgia; E. Tucker Stonecypher, Savannah River Ecology Laboratory, University of Georgia; Christian Swartzbaugh, Savannah River Ecology Laboratory, University of Georgia; Heather Latham, Department of Biology & Geology, University of South Carolina Aiken; Stacey Lance, Savannah River Ecology Laboratory, University of Georgia adam.mcfall@uga.edu
Headstarting is being used in four states to augment and/or reintroduce populations of the at-risk gopher frog (Lithobates capito) and federally listed Mississippi dusky gopher frog (Lithobates sevosa). However, in 2017 researchers began noticing abnormalities in some metamorphs. Since then, the proportion of abnormal metamorphs seems to be increasing both within and among headstarting facilities. In 2021, we headstarted L. capito in cattle tanks in South Carolina and nearly 100% of our frogs developed abnormalities. These included skin, eye, and jaw abnormalities plus edema and redness of the skin. The abnormalities were obvious in metamorphic frogs, but we observed eye issues in tadpoles within four weeks of hatching. Based on necropsies there is no evidence of an infectious agent causing the observed symptoms. The symptoms are, however, consistent with hypervitaminosis A, which may result from excessive exposure to retinoids. Additionally, anecdotal evidence suggests that the abnormalities may be related to the plant substrate used to stock headstarting tanks. Some cyanobacteria have been shown to produce teratogenic retinoids that cause amphibian abnormalities. We are currently comparing the microbial communities in the periphyton grown on sources of Panicum associated with either healthy or abnormal frogs to evaluate correlations between microbes and abnormalities. At this point it is unknown if these abnormalities also occur in the wild. We will discuss the range of abnormalities observed, progression of symptoms, and the importance of determining the cause of gopher frog abnormalities to assess whether this problem extends beyond headstarting. |
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4. 10:45 Optimizing Striped Newt Captive Rearing Based on Post-Release Survival and Developmental Outcomes. Corrie Navis*, University of Georgia; John Maerz, University of Georgia corrie.navis@uga.edu
Captive propagation is a popular strategy for conservation of imperiled amphibians. Evaluating the impact of releasing captive-reared animals can be challenging for species with poorly understood population dynamics, particularly complex life histories, and low detection rates. Striped Newts (Notophthalmus perstriatus) are a species of high conservation concern in south Georgia and northern and central Florida, USA. Numerous organizations are currently involved in Striped Newt captive propagation for repatriation; however, much remains unknown about the species’ complex life history and how captive rearing affects the development and performance of Striped Newts. This information is critical to optimizing captive rearing programs to maximize success. For example, wild Striped Newt larvae commonly metamorphose late into large paedotypic adults that are reproductive within one year or they metamorphose early into a juvenile eft stage that develops slowly on land to adult size. The recruitment of paedotypic adults is hypothesized to be important for Striped Newt population growth. Here we describe how individuals reared in captivity often undergo a metamorphic transformation not documented in the wild where larvae metamorphose directly into a small, “terrestrial” adult or sub-adult form that appear limited in their reproductive potential. We used cohorts of captive-reared F1 Striped Newt larvae of varying ages and sizes (total n=241) to estimate the effects of larval size at release on survival and probability of developing into a paedotypic adult. We discuss ongoing studies of captive-reared larval performance and how our results can be used to optimize captive rearing efforts for this species. |
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5. 11:00 Fish Assemblage Patterns Across the South Central Plains of Arkansas: A Preliminary Analysis. Ryne Lehman*, University of Central Arkansas; Molly Wozniak, University of Central Arkansas; Hal Halvorson, University of Central Arkansas; Ginny Adams, University of Central Arkansas; Reid Adams, University of Central Arkansas rlehman@cub.uca.edu
Anthropogenic land use alterations can have negative impacts on physical in-stream habitat, water quality, and community structure within aquatic ecosystems. Low gradient streams are understudied, with few studies investigating the relationship between anthropogenic land use and low gradient streams. Low gradient streams located across the South Central Plains Ecoregion of Arkansas are no exception. Quantifying the relationship between land use and fish assemblage structure patterns can provide supplemental data to aid with developing criteria for future ecosystem management within the region. Eighteen sites were sampled during summer 2021 for fish, physicochemical, flow, and physical in-stream habitat data. In addition, water samples were collected monthly across all 18 sites to provide a more detailed analysis of water chemistry data. A total of 3,329 individuals and 40 fish species were collected and species richness varied from 11 to 27 species per site. Fish communities varied across sites based on NMDS ordination using fish relative abundance. Physicochemical parameters and total dissolved metal concentrations collected during summer season were analyzed using PCA. Patterns of fish community structure in relation to land use, physicochemical, and physical in-stream habitat data will be discussed. |
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6. 11:15 Dietary and Morphological Changes in Luxilus pilsbryi in Response to Stream Drying. Jessica Rath*, University of Central Arkansas; Rebeka Bradford, University of Central Arkansas; Sahara Morgan, University of Central Arkansas; Chance Garret, University of Central Arkansas; Ginny Adams, University of Central Arkansas; Reid Adams, University of Central Arkansas jrath1@cub.uca.edu
Intermittent streams, characterized by cessation of flow over lengthy periods of time, play an essential role in maintaining biotic diversity and integrity of perennial streams. Adaptations of fishes to these conditions include increased diet breadth and, in one study, changes in gut length when food quality and quantity decreased. Luxilus pilsbryi, the Duskystripe Shiner, is an Ozark endemic found in both intermittent and perennial streams, with a diet characterized as primarily macroinvertebrates with some algae and plant material. Individuals were collected across all seasons from Rockhouse Creek, an intermittent tributary, and during the winter, spring, and summer in Piney Creek, a perennial tributary of the Kings River. We found gut length (adjusted for standard length) varied significantly across seasons and streams (ANCOVA, p<0.001). Stomach contents were then examined and identified to the lowest possible taxon, enumerated, and massed. Individuals collected in spring consumed more total food (by mass) relative to all other seasons in both Rockhouse and Piney creeks. Winter and spring stomachs contained mostly aquatic invertebrates; summer and fall stomachs from Rockhouse Creek contained mostly amorphous material—consisting of plant, detrital, and algal materials, while stomachs from Piney Creek did not exhibit a significant shift in the amount of amorphic material consumed across seasons (Wilcoxon, p=0.164). The seasonal shift to a more herbivorous diet in Rockhouse Creek did not correspond with increased gut length, suggesting L. pilsbryi cannot compensate during low food periods through morphological adjustments of gut length and may reflect their facultative association with intermittent headwater streams. |
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7. 11:30 Body Shape and Mode of Propulsion Do Not Constrain Routine Swimming in Coral Reef Fishes. Darien Satterfield*, University of California, Davis; Thomas Claverie, 3.; Peter Wainwright, University of California, Davis drsatterfield@ucdavis.edu
It is widely believed that because of biomechanical trade-offs, fish body shape and the mode of propulsion are strong predictors of swimming performance, with the best cruisers, maneuverers, and accelerators having different body forms and emphasizing different propulsion mechanisms. This paradigm is regularly projected onto routine swimming behavior and dominates the ecomorphological literature, despite the difficulties in obtaining field measurements of swimming. In this study, we measured variation in swimming behavior among 48 species of Indian Ocean coral reef fish using recordings from a remote stereo video system. We measured average swimming speed, average swimming bout distance, frequency of turns, and percent of time spent station-holding and looked for the predicted trade-offs between them. We find almost no evidence of trade-offs between swimming behaviors across species, little evidence that body elongation ratio affects swimming, and few differences between species that swim by undulating the body and those that emphasize the use of median and paired fins. Taxa widely thought of as archetypical maneuverers (Chaetodon) and cruisers (Caranx) were not outliers in any behaviors. Our results indicate that swimming behavior is not easily predicted from simple measures of body shape and that alternative swimming modes can produce comparable behavioral profiles. |