Master of Science, Miami University, 2024, Biology

Duckweed, aquatic macrophytes in the family Lemnaceae, are used in phytoremediation because of their ability to uptake nutrients but are also viewed as pests due to their tendency to rapidly reproduce and cover ponds. This study examined how the interaction of duckweed and nitrogen addition impacts amphibian metamorphosis. Because duckweed has been shown to alter light and algal levels and amphibian larvae consume algal food resources, I hypothesized that duckweed presence negatively impacts amphibian larval development by altering algal levels and that this effect intensifies with nitrogen fertilizer addition. To test this, I conducted mesocosm studies with three species of anuran larvae, in which I manipulated two factors, duckweed (present or absent) and ammonium nitrate (present or absent), and measured abiotic conditions of the aquatic environment, algal abundance, and metamorphosis endpoints. The addition of nitrogen benefited anuran metamorphosis, although no increases in algal abundance were measured. Despite impacts on abiotic factors in the aquatic communities, duckweed had no negative impacts on anurans and some positive effects, such as increasing northern leopard frog biomass, which suggests that duckweed at densities used in this study do not pose a threat to habitat quality for amphibian larval development.

Committee: Michelle Boone (Advisor); María González (Committee Member); David Gorchov (Committee Member) Subjects: Ecology

Master of Science (MS), Wright State University, 2018, Biological Sciences

Amphibian populations are declining globally at historically rapid rates, and while a multitude of factors have contributed to amphibian population declines, emerging infectious diseases, such as chytridiomycosis and ranavirus have been linked to a large proportion of the reported amphibian mass mortality events. Distribution and infection prevalence data for chytridiomycosis and ranavirus are lacking, and effective surveillance is crucial. This project aims to describe anuran richness, relative abundance, habitat occupancy, and community structure and to identify the chytridiomycosis and ranavirus infection prevalence rates of the anuran population at Dairymen's Inc. Wood frogs, spring peepers, boreal chorus frogs, northern leopard frogs, gray treefrogs, American toads, green frogs, mink frogs, and American bullfrogs were the nine anuran species that were recorded in Vilas County, Wisconsin. The infection prevalence rates of Bd and frog virus 3 were 11 ± 5.6 with 95% C.I. and 0%, respectively. This study is the first to report the presence of Bd-infected anurans in Vilas County, however further research is needed to provide reliable frog virus 3 infection rates in this county.

Committee: Thomas Rooney Ph.D (Advisor); Volker Bahn Ph.D. (Committee Member); Jeffrey Peters Ph.D. (Committee Member) Subjects: Biology

Doctor of Philosophy (Ph.D.), Bowling Green State University, 2024, Biological Sciences

As human-modified landscape and climate changes proliferate, maintaining biodiversity and understanding the function and quality of available habitat is imperative. Anurans (frogs/toads) can be indicator species of habitat quality and ecosystem productivity, due to their permeable skin, small body size and ectothermy. We explored the relationship between Anurans and habitat quality by assessing the effects of spatial and temporal heterogeneity on the presence of Anurans. Across the Toledo Metropolitan Area (TMA), including the biodiversity hotspot Oak Openings Region (OOR), we surveyed across three years, 67 different wetland sites (N=1800). There was a difference in community assemblage between rural and suburban/urban habitats driven by factors related to human-modification (impervious surface), composition (landcover type) and productivity (e.g., NDVI). Areas with more impervious surface, lower amounts of swamp forest, and lower NDVI had fewer species. The differences in spatial structure but lack of differences in temporal variables among sites suggest spatial factors dominated. We also developed spatial models for predicting species richness across the region to evaluate spatial variables driving community composition and ecosystem productivity. The amount of cropland best predicted species richness, followed by amount of swamp forest. Among individual species, the most important variables differed; cropland (Acris blanchardi, Lithobates catesbeianus, Anaxyrus americanus, Anaxyrus fowleri and Hyla versicolor), floodplain forest (Lithobates clamitans), wet prairie (Lithobates pipiens), and swamp forest (Pseudacris crucifer, Pseudacris triseriata, Lithobates sylvaticus) were leading influences. Finally, we surveyed 304 local residents to assess their views on topics from support of new parks/preserves to fees to utilize parks, before a 25-minute presentation on Anurans, and resurveying them. There was strong support for many conservation-oriented questions, but (open full item for complete abstract)

Committee: Karen Root Ph.D. (Advisor); Paul Moore Ph.D. (Committee Member); Ashley Ajemigbitse Ph.D. (Other); Jeffrey Miner Ph.D. (Committee Member); Helen Michaels Ph.D. (Committee Member) Subjects: Biology; Conservation; Ecology; Wildlife Conservation; Wildlife Management

Doctor of Philosophy, Case Western Reserve University, 2024, Biology

Organisms are shifting breeding phenology and thus exposing offspring to novel photoperiods. Rising global temperatures are also expanding the growing season and changing the relationship between photoperiod and temperature. This raises the question of whether species' responses to photoperiod that evolved prior to contemporary climate warming could lead to maladaptive responses under future global change. In Chapter 1, I examined how photoperiods representing two seasons affected freshwater communities composed of amphibians, phytoplankton, periphyton, and zooplankton. Both gray treefrogs and green frogs developed faster under the early-season photoperiod, and copepod nauplii abundance also increased. While there were taxa-specific effects of photoperiod, there were no widespread shifts in community composition nor strong indirect effects detected across the community. In Chapter 2, I explored the carryover effects of photoperiod and temperature, as well as their potential interaction, on gray treefrog life history. Both early- and late-season (shorter) photoperiods and the warm temperature treatment increased development rate but had opposing effects on size at metamorphosis: the shorter photoperiods reduced size, and the warm treatment increased size. While juveniles from the warm treatment grew slower during the short-term growth period after metamorphosis, there was no effect on long-term growth. Conversely, juveniles from the shorter photoperiods did not grow differently from the longer (average-season) photoperiod during the short-term growth period but grew slower during the long-term growth period. Overall, photoperiod had stronger effects across amphibian traits than that of temperature. In Chapter 3, I investigated the effects of three photoperiod treatments on traits associated with overwintering ability in gray treefrogs. Juveniles under the late-season photoperiod exhibited dramatically increased cryoprotectant levels, greater cold tolerance, and reduc (open full item for complete abstract)

Committee: Michael Benard (Advisor); Elliot Gardner (Committee Chair); Diana Koester (Committee Member); Jean Burns (Committee Member); Karen Abbott (Committee Member) Subjects: Biology; Climate Change; Ecology; Freshwater Ecology; Zoology

Bachelor of Sciences, Ohio University, 2022, Biological Sciences

Amphibians are indicator species of ecosystem health due to their high susceptibility to changing environmental conditions, whether it be natural or anthropogenic changes. Amphibians also play a key role in many ecosystems, such as moving nutrients between terrestrial and aquatic habitats. It is important to understand how populations change over time in response to different environmental pressures to support successful land management strategies. Wayne National Forest (WNF) in Southeast Ohio harbors a rich amphibian fauna, and wildlife managers monitored pond-breeding anuran (frog) species to determine the best forest management strategies for their protection. The goal of this project was to quantify pond-breeding amphibian community dynamics in WNF in relation to different land management strategies and environmental predictors using a hierarchical modeling framework. Using the North American Amphibian Monitoring Program protocol, data was collected at 30 sites March through June from 2005-2018. A total of 14 species were studied, with zero detections for the Eastern Spadefoot Toad (Scaphiopus holbrookii) to hundreds for species such as the Spring Peeper (Pseudacris crucifer). We ran dynamic occupancy models and then using AIC values determined model suitability and what abiotic factors were the best predictors of occupancy. Month and air temperature, for example, were the best predictors of American Toad occupancy. Using these results, we will then share them with WNF to aid them in determining effective land management strategies and to assist them in resecuring federal funds for amphibian monitoring programs.

Committee: Viorel Popescu (Advisor) Subjects: Biology; Ecology

Doctor of Philosophy, Miami University, 2022, Ecology, Evolution and Environmental Biology

Biodiversity loss is occurring at unprecedented rates which calls for an increase in research focused on how human land use can minimize effects on natural ecosystems and their inhabitants. Exurban landscapes are large lot residential areas, between rural and suburban landscapes, and is the largest increasing land use in the United States since the 1950s. Exurban landscapes are a relatively new land use type; therefore, the relative significance of large lot residential properties on biodiversity is not well understood. However, exurban patches may act as an oasis for local species, but their biological potential depends upon the management strategies implemented by residents as well as the surrounding habitat. Given the known impact of habitat loss and fragmentation it is imperative to determine how changes in land use and land cover impact biodiversity across varying spatial and temporal scales. The aim of my research is to determine how anthropogenic and environmental factors as well as management decisions influence anuran diversity on exurban landscapes. My central hypothesis is that landscape factors such as land cover and landscape configuration will influence anuran occurrence, abundance, and richness more than local factors, such as parcel size and pond management via chemical use. I predict factors that impact pond quality (such as chemical exposure and pond area) will significantly influence anuran richness, abundance, and occurrence at the parcel level, while landscape factors, such as land cover, will significantly influence anuran richness, abundance, and occurrence at the landscape level. I used experimental studies, field surveys, and species distribution modeling to determine which factors significantly contribute to local anuran occurrence, abundance, and richness in an agriculturally dominated habitat matrix. Overall, I found pond management, through chemical application, to have no impact on anuran metamorphosis. However, I found that richness on (open full item for complete abstract)

Committee: Michelle Boone (Advisor); Amelie Davis (Committee Member); Michael Vanni (Committee Member); Ann Rypstra (Committee Member); Thomas Crist (Committee Member) Subjects: Biology; Ecology; Environmental Science

Master of Science (MS), Wright State University, 2017, Biological Sciences

The Pacaya-Samiria National Reserve of Peru is one of the largest protected areas of the Amazon rainforest, yet it has hosted only a few studies of frogs and toads (anurans). The primary goals of my study are: 1) To conduct an inventory of the local anuran species, 2) to quantify richness among habitats, 3) to compare differences in beta diversity across a river versus a continuous landscape, and 4) to compare difference in body size between nocturnal and diurnal individuals. After eight weeks of daytime and nighttime surveys during the dry season, a total of 601 individuals were identified across 28 species and 6 families. Of these 601 individuals, 50% were found on aquatic vegetation, 29% were found in the forest during the nighttime, and 21% were found in the forest during the daytime. Beyond describing the community composition and species richness, I also quantified the overall diversity and found a difference of body size between diurnal and nocturnal anurans. The overall diversity of the region seems to be mostly from local alpha diversity, but beta diversity was slightly higher than expected when considering populations on opposite sides of the river. This might indicate that the wide rivers of this region are weak barriers of dispersal for anurans. Furthermore, a Wilcoxon rank-sum test showed with great significance that there is a difference of body size between diurnal and nocturnal anurans in this region. This might support theories that anuran species are driven apart by interspecific competition and intraguild predation, or that only larger species can tolerate the cooler temperatures during the nighttime. In conclusion, it would help future studies to spend a greater length of time in the region, to be performed during the wet season as well as the dry season, and to collect data more relevant to explaining any underlying forces influencing the community.

Committee: Thomas Rooney Ph.D. (Advisor); Volker Bahn Ph.D. (Committee Member); Lynn Hartzler Ph.D. (Committee Member) Subjects: Biology; Conservation; Ecology

Doctor of Philosophy, Miami University, 2014, Biological Sciences

Winter presents organisms inhabiting temperate regions with various stresses, including low temperature. To contend with subzero temperatures, a small group of ectotherms tolerate freezing, in part through the use of cryoprotective solutes. In the wood frog, Rana sylvatica, glucose serves an important role in freezing survival; however, the mechanisms underlying the transport and distribution of cryoprotectants such as glucose are not fully understood. This dissertation describes several studies that examined a glucose transport protein (GLUT2) and its importance in the freeze tolerance of R. sylvatica. First, I identified and functionally characterized a GLUT2 homolog from R. sylvatica to understand its role in glucose homeostasis. The newly identified GLUT2 was structurally and phylogenetically similar to other known GLUT2s. Measurements of transport kinetics in Xenopus oocytes determined that GLUT2 from R. sylvatica is functionally similar to previously characterized GLUT2s. This protein was found in various tissues but was most abundant in liver. Finally, transport kinetics were similar among two populations of R. sylvatica, and R. pipiens; however, GLUT2 abundance was greatest in the northern R. sylvatica. R. sylvatica relies on glucose to survive multiple winter-related stresses, and the second study examined regulation of GLUT2 in response to these stresses. GLUT2 expression increased in response to organismal freezing, hypoxia exposure, and glucose loading; whereas, experimental dehydration and urea loading had no effect. These changes were the result of transcriptional regulation, resulting in synthesis of new protein. Results of this study suggest that hepatic GLUT2 is regulated to meet the physiological need to accumulate glucose. Subarctic populations of R. sylvatica survive freezing to lower temperatures than conspecifics from temperate regions. In the last study, I sought to determine if GLUT2 contributes to the profound freeze tolerance of northe (open full item for complete abstract)

Committee: Richard Lee PhD (Committee Co-Chair); Jon Costanzo PhD (Committee Co-Chair); Paul James PhD (Committee Member); Yoshi Tomoyasu PhD (Committee Member); Carole Dabney-Smith PhD (Committee Member) Subjects: Biology; Physiology; Zoology

Doctor of Philosophy (PhD), Ohio University, 2013, Biological Sciences (Arts and Sciences)

Frogs show a variety of locomotor behaviors (swimming; walking; burrowing; hopping; climbing; jumping; gliding) that have allowed them to radiate globally to fill a diverse array of ecological niches. Studies of frog locomotion have previously focused on the role of the hindlimbs during jumping. There remains a paucity of information regarding the functional morphology of the frog trunk and pelvis and their relation to locomotor modes. Additionally, the evolution of these locomotor traits has not been studied in a phylogenetic context. This dissertation research elucidates the relationship of the frog axial and pelvic musculoskeletal system with different frog locomotor modes to assess evolutionary patterns in locomotor morphology. In the second chapter I re-examine adult axial and pelvic bony characters with respect to pelvis type and hypothesis of primary mode of locomotion in a large taxonomic sample of exant and fossil frogs to assess the anuran basal pelvic-state and locomotor condition. Results from this research are that the lateral-bender pelvis (little to no ilial/urostyle ridges), walker/hopper condition is both basal and conserved across the Anura, the sagittal-hinge pelvis (with ilial/urostyle ridges) is correlated with long-jumping and does not appear in the phylogeny until well within the Neobatrachia, and burrowing behaviors appear to have had a canalizing effect on axial/caudal rigidity, either with bicondyly or fusion of the sacrourostylic joint. The third chapter describes covariation of whole-body skeletal morphometrics in relation to four locomotor modes and two pelvic types from 188 frog genera to establish the most reliable bony character(s) for estimating primary locomotor mode. Estimates are free from the confounding effects of phylogeny with use of newly derived comparative methods. I found the shape of the sacrum to provide the most insight into differences among locomotor modes (rather than hindlimb length as previously descri (open full item for complete abstract)

Committee: Stephen Reilly (Advisor) Subjects: Morphology

Master of Science, University of Akron, 2008, Biology

Both concern over amphibian declines (Dunson et al., 1992; Blaustein, 1994) and the potential of amphibians as indicators (Phillips, 1990; Dunson et al., 1992; Boyer and Grue, 1995) of ecosystem health provided the impetus for this study. Utilizing amphibians as indicator species is comparable to the use of canaries in a coal mine when assessing the quality of an aquatic environment (Barinaga, 1990). Embryos, tadpoles, and adults are considered to be sensitive to environmental contaminants in part due to their unshelled eggs and permeable skins (Bridges et al., 2002; Blaustein et al., 2003; Kiesecker et al., 2004; Hogan et al., 2006). Amphibians offer a unique biphasic life cycle for studying water and land habitats as well as the interactions between the two environments. This study investigated the interaction between two human-mediated environmental changes on the development of a common North American anuran, (Rana sylvatica) the Wood Frog. Anthropogenic changes have increased copper and sunlight in many amphibian habitats. Human disturbance often leads to a decrease in canopy cover, which thereby reduces shade for developing embryos and tadpoles of certain anuran species within the aquatic environments below (Werner and Glennemeier, 1999; Skelly et al., 2002). Water runoff from impermeable surfaces and agricultural and residential properties transport toxins and excess nutrients into bodies of water, leading to algal blooms. In ponds, a common algaecide utilized to eliminate the ensuing blooms is copper sulfate. This work investigated the effects of copper sulfate and increased solar radiation on the developmental rate and survival of Wood Frog tadpoles in high pH ponds. pH levels in Northeastern Ohio ponds are higher (7.0-8.5; Matson et al., unpublished data, 2006) than in many other areas of Wood Frog study and research is lacking in non-lab environments at these pH levels. A field study used cattle tanks for testing the influence of increased light, incre (open full item for complete abstract)

Committee: Francisco Moore PhD (Advisor); Brian Bagatto PhD (Committee Member); Timothy Matson PhD (Committee Member); Peter Niewiarowski PhD (Committee Member) Subjects: Aquaculture; Ecology; Environmental Science; Freshwater Ecology