Digital Commons Network^™

Temporal Partitioning And Coexistence Among Four Sympatric Felid Species In The Northern Jaguar Reserve, Kylie Marie Rezendes

Open Access Theses & Dissertations

Coexistence among sympatric carnivores is shaped by behavioral strategies that mediate competition and mortality risk in heterogeneous landscapes. Understanding how sympatric carnivores, such as felids, use space and time in relation to one another requires models that account for both spatial and temporal overlap across landscapes. Models incorporating time-to-event probabilities provide a powerful framework for detecting behavioral dynamics across shared landscapes. This study evaluated the spatiotemporal responses of two apex predators â?? the jaguar (Panthera onca) and mountain lion (Puma concolor) - and two mesopredators - bobcat (Lynx rufus) and ocelot (Leopardus pardalis) - across five years of camera trap …

Phylogenetics And Integrative Taxonomy Of The Lang's Reed Frog Species Complex (Anura: Hyperoliidae: Hyperolius Langi), Dominic Troiani

Open Access Theses & Dissertations

The genus Hyperolius (Rapp, 1842) is the most speciose amphibian genus in sub-Saharan Africa. The genus has a complex taxonomic history because of its extensive intraspecific and interspecific morphological variation, large geographic distribution of many taxa, gaps in sampling, and the discovery of significant cryptic diversity within many species. The goal of this study is to understand the relationships and taxonomy of Hyperolius langi via an integrative taxonomic approach that combines molecular, morphological, and bioacoustics data to clarify the systematics of the geographically widespread species Hyperolius langi. Two mitochondrial (16S and cyt b) and one nuclear (RAG1) gene were used …

Assessment Of Floral Resources From Three Tamaulipan Thornscrub Communities Of The Lower Rio Grande Valley, Gracie Makenna Granados

Theses and Dissertations

The Tamaulipan thornscrub is a transition zone between the neotropics and the temperate regions, harboring high biodiversity. This habitat supports a diverse insect community, including many pollinators of native and cultivated plants in Texas and northeastern Mexico. This ecosystem has been extensively degraded and lost; only 5% of its original cover remains north of the Rio Grande. Restoration of the Tamaulipan thornscrub has been ongoing for over three decades, but the important roles of pollinators in the success of such efforts and the functioning of the restored ecosystem have rarely been considered in restoration efforts. The purpose of this study …

Gut Passage Time In Small Mammals: Influences Of Small Mammal Traits, Digesta Phase, And Particle Morphology, Noah G. Hale

Electronic Theses and Dissertations

Dispersal is crucial in maintaining healthy ecosystems, but little is known about mechanisms influencing fungal spore dispersal by animals. We aimed to develop a more mechanistic understanding of the influence of fungal spore traits and small mammal traits on gut retention time. We fed three species of small mammals (shrew, mouse, vole), which differ in gut morphologies, digestive strategies, and activity a combination of markers including: liquid digesta phase (CrEDTA), small particle (fungal spores with diverse morphologies), and large particles (glitter and beads, representing plant cells and seeds, respectively). We found that hindgut fermenters selectively retained the liquid markers, spores …

Cattle Regenerative Grazing Effects On Bat Activity In Southern Appalachia, Seth Morelock

Electronic Theses and Dissertations

Livestock farming accounts for about 70% of agricultural activity, with continuous grazing as the dominant conventional practice. However, this method often degrades biodiversity and ecosystem health through overgrazing. Regenerative grazing practices offer a potential ecologically sustainable approach to cattle management. Insectivorous bats are known to use agroecosystems for foraging and roosting habitats, offering an opportunity to assess their response to regenerative grazing. Using passive acoustic monitors, we evaluated the response of bats to cattle within regenerative grazed farms in East Tennessee, USA. Overall bat activity declined when cattle entered and exited paddocks, except for the tri-colored bat (Perimyotis subflavus …

Mixture Effects On Metal Accumulation In The Asian Clam, Corbicula Fluminea, Mark A. Huff

Electronic Theses and Dissertations

Field collected Corbicula fluminea were exposed to trace level copper, lead, and zinc with the aim of examining the preferential accumulation between the soft tissue and shell. Metal levels were based on those in a permitted industrial effluent. At 1X effluent and 2X effluent exposure levels, copper was found to preferentially accumulate in the clam soft tissue, lead was found to preferentially accumulate in the clam shell, and zinc was found to excrete back into the diluent after preferentially accumulating in the clam soft tissue. When exposed as a mixture at 1X effluent levels, copper and lead were found to …

Investigating The Impact Of Psychoactive Plant Alkaloids On Bumblebee Behavior, Skylar Mathieson

Electronic Theses and Dissertations

The relationship between plants and their pollinators is often framed as a food-for-service exchange in which plants provide pollinators with nutrients in exchange for transport of their gametes. However, in addition to essential nutrients, many floral rewards (nectar, pollen) also contain defensive toxins such as alkaloids, with largely unexplored consequences for plant-pollinator interactions. I investigated how three psychoactive and addictive plant alkaloids — caffeine, nicotine, and morphine — affect foraging behavior in generalist bumblebees (Bombus impatiens) using robotic flowers. Each of these chemicals affected pollinator foraging behavior, influencing the number and duration of their visits to flowers in …

Drivers And Consequences Of Changes In Nectar Microbiome Composition Across Spatial And Biological Scales, Daniel A. Barker

Electronic Theses and Dissertations

Microbial communities inhabiting floral nectar, known as the nectar microbiome, are important mediators of plant-pollinator interactions. However, the ecological and environmental factors that shape the composition of these microbial communities remain poorly understood. While previous studies have examined the effects of a few microbial groups, typically independent of one another, on one plant or pollinator species, this dissertation takes a wide-scale approach to explore how abiotic conditions and biotic interaction’s structure microbial communities within floral nectar. Furthermore, I also quantify how variation in microbial richness and identity influences pollinator behavior and plant reproductive success.

This dissertation shows that microbial abundance …

Association Between Gene Family Expansion And The Rapid Diversification Of Pleurocarpous Mosses, Meredith A. Cobb

All Theses

Mosses are the second most species-rich group of land plants. They represent a critical group for understanding the evolution and diversity of land plants. Mosses comprise two major groups, acrocarps and pleurocarps. Despite having a more recent evolutionary origin than acrocarps, pleurocarps are exceptionally diverse. The difference in species richness reflects a rapid species diversification, roughly coincident with the origin and diversification of flowering plants. The speciation events giving rise to pleurocarp diversity happened so rapidly, making it historically difficult to produce strongly supported phylogenies with which to test evolutionary hypotheses. One such hypothesis is whether large-scale changes at the …

Small Stream Restoration In The Piedmont Of South Carolina: Comparison Of Evaluation Tools And Water Quality’S Effects On Salamanders, Camryn Lachica

All Theses

For many years, the United States Army Corps of Engineers (USACE) used the Guidelines for Preparing a Compensatory Mitigation Plan worksheets to guide pre-restoration evaluation and determine post-restoration mitigation credits in South Carolina. Recently, the USACE in South Carolina transitioned to the Stream Quantification Tool (SQT), which provides a more comprehensive assessment framework. Our first objective was to compare these assessment methodologies across different landscape types to determine what the SQT adds to mitigation calculations that were not considered in prior worksheets. We evaluated 16 streams in the Piedmont of South Carolina, with four replicates each of forested, suburban, urban, …

Striped Bass (Morone Saxatilis) Movement And Habitat Selection In The Edisto River, South Carolina, Jacob Hill

All Theses

Striped Bass (Morone saxatilis) are a commercially and recreationally important fish native to the Atlantic Coast of the United States. They possess a diversity of life history strategies, with northern populations tending to be anadromous and southern populations being primarily river residents. In general, southern populations are less studied, posing challenges for effective management. Between 2019 and 2024, we tagged 37 Striped Bass with acoustic telemetry transmitters in order to study seasonal migration patterns and summer habitat selection. We estimated migration probability for both the spring and fall Striped Bass migrations using data from an array of passive …

Changing Globally, Acting Locally: Responses Of Coastal Plant Functional Traits To Global Change Are Mediated By Biotic And Abiotic Interactions., Shannon L. Walker

Electronic Theses and Dissertations

We live in a time of rapid global change with substantial consequences for planet-wide functioning. Local ecosystems reflect this change, yet we struggle to predict their responses. Coastal ecosystems, like dune and interdunal wetlands, have declined rapidly and predicting their responses to global change is essential for future management. Functional traits may be particularly informative as they drive species and ecosystem responses and can provide generalizable findings. This dissertation investigates how global change, especially anthropogenic nitrogen (N) enrichment, interacts with abiotic and biotic factors to affect coastal sand dune and interdunal wetland plant functional traits. First, I used a long-term …

Ecosystem Services Of Urban Green Spaces In Louisville, Ky., Julia Kachanova

Electronic Theses and Dissertations

Accelerating urbanization poses critical challenges to urban green spaces (UGS), vital for ecological balance and human health. Rapid development often results in fragmented habitats, biodiversity loss, and diminished ecosystem service delivery. There is an urgent need to explore and evaluate novel strategies capable of enhancing urban resilience, such as implementing urban orchards, and managing existing parks and gardens in sustainable ways. This dissertation explores how different forms of urban green spaces (UGS) contribute to the provision and maintenance of critical ecosystem services that support human well-being and urban biodiversity. By analyzing UGS impact on ecosystem service provisioning and long-term sustainability, …

Linked Lives In The Riverbed: Integrating Fish Host Dynamics, Community Structure, And Demography For Freshwater Mussel Conservation., Jonathan Patrick Frommeyer

Electronic Theses and Dissertations

Freshwater mussels are long-lived benthic invertebrates that play key roles in nutrient cycling, water filtration, and habitat stability in rivers and streams. Despite their ecological importance, they are among the most imperiled faunal groups in North America, with their persistence increasingly threatened by environmental degradation and disruptions to host–parasite dynamics. This dissertation integrates host ecology, community structure, and demographic modeling to assess population viability and guide conservation priorities for mussel species in Kentucky river systems. The first chapter introduces the ecological context and conservation urgency surrounding freshwater mussels. In particular, emphasizing the need for multi-scale approaches to understand how parasitic …

Social And Economic Gradients Of Resource Transfer Behavior In Gorongosa, Mozambique, Karl J. Mertens

Boise State University Theses and Dissertations

Why do people who experience the same environmental and social conditions vary so much in their resource transfer behavior? This dissertation addresses that question through examination of behavioral variation in subsistence horticulturalists in the dry tropical forest bufer conservation area of Gorongosa National Park in Mozambique. In this region of moderate and acute food shortages at both household and regional levels, individuals face similar challenges of addressing social and resource uncertainty yet respond with marked behavioral variation that cannot be explained solely by diferences in wealth, kinship, or reciprocity patterns.

Using a Behavioral Reaction Norms (Dingemanse et al., 2010) (BRN) …

What's The Value Of A State? Accounting For The Ecosystem Services And Natural Capital Of Oregon, Kathryn Liebrecht

University Honors Theses

Ecosystem services are vital to human welfare and society, but often are overlooked when it comes to planning and setting policy. By neglecting to incorporate the benefits received from natural resources, policy makers may unknowingly be making decisions that harm the long term sustainability and use of these services. To highlight the importance of Oregon's ecosystems, the present study aims to provide a full accounting of the ecosystem services and natural capital of the state. Using data from the Institute for Natural Resources' updated Oregon statewide habitat map, Oregon's ecosystems were matched to biome categories from the Ecosystem Services Valuation …

Distribution, Roles And Environmental Drivers Of Bacterial Communities In The Chesapeake And Delaware Bays, Mir Alvee Ahmed

All Dissertations

In this dissertation, water samples from the Chesapeake and Delaware Bay estuaries were analyzed to see how estuarine environmental gradients drive distributions, functional potential, growth estimates and gene expressions of bacteria. To answer this, the abundant and versatile taxa– Rhodobacterales and Actinobacteriota, along with broader particle-attached (PA) vs. free-living (FL) bacterial assemblages of these Bays were analyzed using a multifaceted ‘omics approach.

The PA fraction, differing from the FL in taxonomy, distribution, functional potential and estimated growth rates across salinities, and bays harbored genes degrading complex aggregates, and surface attachment. The FL counterpart presented genes involved in nutrient uptake …

Ecomorphological Diversification Of Tooth Complexity In The Oral Jaws Of Marine Teleostean Fishes, Keiffer L. Williams

All Dissertations

Teeth are essential biological tools that function as a direct interface between predator and prey, thus providing essential insights into the evolutionary history and ecological diversity of vertebrates. Historically, studies on vertebrate dentitions have been qualitative and focused on mammals. More recently, quantitative methods have been developed that can reliably measure tooth surface complexity. These methods have been applied across both mammals and saurian reptiles to test for correlations with diet, leading to the conclusion that herbivorous species generally possess higher overall tooth complexity than any other dietary group. Surprisingly, the relationship between tooth complexity and diet in the most …

Cutting Propagation And Out-Planting Of White-Margined Beardtongue (Penstemon Albomarginatus M.E. Jones), A Vulnerable Herbaceous Perennial Of The Mojave Desert), Alexander Stosich

All Graduate Theses and Dissertations, Fall 2023 to Present

Plant biodiversity is crucial for the proper functioning of ecosystems, with many species needed to maintain the variety of functions provided, especially with increasing environmental change. However, plant biodiversity is threatened in many different ecosystems, primarily through habitat loss. Species can be conserved by protecting their original habitat and mitigating for threats such as invasive species or altered disturbance regimes (plant conservation); however, with declining population numbers and continued habitat loss and/or disturbance, it may be necessary to actively move plants (plant restoration). Plant restoration is dependent on developing the capacity to a) reliably propagate plants in a nursery and …

From Rifles To Running Shoes: How Outdoor Recreation Trends Are Reshaping Conservation Efforts, Lane James Arthur

All Graduate Theses and Dissertations, Fall 2023 to Present

Parks and protected areas (PPAs) serve a dual purpose: they conserve wildlife and natural habitats while providing spaces for people to enjoy outdoor recreation. However, balancing conservation with recreation can be challenging, especially as outdoor activities continue to grow and evolve. In Utah, Wildlife Management Areas (WMAs) are set aside to protect important wildlife habitats and provide opportunities for hunting and fishing. Recently, these areas have seen an increase in activities such as mountain biking, trail running, and dog walking, some of which take place in areas which prohibit recreational activity in effort to protect wildlife. These shifts in recreation …

Assessing Long-Term Changes In Aspen Forest Cover In Northern Yellowstone National Park Before And After Carnivore Recovery, Nicholas J. Bergeron

All Graduate Theses and Dissertations, Fall 2023 to Present

The recovery of large carnivores (wolves, bears, cougars) in Yellowstone National Park and the subsequent decline of the area's elk herd have raised key questions about ecosystem restoration—particularly for species such as aspen, which are heavily browsed by elk. Following wolf reintroduction in the mid-1990s, scientists began tracking changes in browsing intensity and height of young aspen within sampling plots, assuming reduced browsing and taller stems were signs of population recovery. However, no studies have measured whether the total area covered by aspen stands actually increased, as would be expected with broader recovery. Moreover, the potential influence of climate change …

Exploring Biotic And Abiotic Drivers Of Ecosystem Properties: The Influence Of Waterbirds And Photodegradation On Wetland Ecosystems, Lindsay Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

Wetlands provide a wide range of valuable ecosystem services: these are benefits from the environment that support human well-being, such as water filtration, fish and bird habitat, and shoreline protection. Despite their importance, wetlands are among the most threatened ecosystems, facing increasing pressure from natural and human activities. To better predict the future of wetlands and guide effective management and restoration practices, we need to understand the various forces shaping their ecological properties. In this thesis, we examined the influence of two forces: waterbirds and photodegradation (the process by which sunlight breaks down plant material). To explore each of these …

Modeling For Functional Traits In Bluebunch Wheatgrass Using Unmanned Aerial Vehicle (Uav) High-Throughput Phenotyping, Brittany L. Johnson

All Graduate Theses and Dissertations, Fall 2023 to Present

Changing climates and shifts in community composition in the Intermountain West threaten sagebrush-steppe ecosystems, impacting both plants and animals. Restoring native grasses like bluebunch wheatgrass (Pseudoroegneria spicata; BBWG) can help ecosystems resist invasive species and recover from stress and disturbances. As a native cool-season grass, BBWG is widely used in rangeland restoration for the western U.S. Breeding programs for restoration plant materials, such as seeds for ecological projects, often require years or decades of field testing while facing staffing constraints. High- throughput phenotyping (HTP), which rapidly measures observable plant traits, offers a faster solution using drones to capture time-series …

Using Livestreaming Technology To Answer Novel Questions About The Behavior And Physiological Ecology Of The Prairie Rattlesnake (Crotalus Viridis), Max C. Roberts

Master's Theses

Recent advances in remote monitoring technology are opening up new opportunities for developing innovative natural history and biological research methodologies. In particular, the emergence of livestreaming camera technology has made recording remote video of wild and secretive animals much easier and made it possible to collect data at extremely fine temporal resolutions. In 2024, Project RattleCam launched a livestreaming camera at a Prairie Rattlesnake (Crotalus viridis) den in Colorado. The goal of this work was to study Prairie Rattlesnake behavior 24-7 throughout the species’ active season with minimal human disturbance. Additionally, I used this system to study the …

Investigating Rattlesnake Social Networks And Improving Their Public Image Through Unobtrusive Technologies And Community Science, Owen M. Bachhuber

Master's Theses

While technology is often blamed for humans’ increasing disconnect with nature, it can also serve as a tool to facilitate empathy and conservation action for wildlife. Snakes are among the most feared animals on the planet, though their understudied social interactions provide opportunities to make scientific discoveries and change public perceptions. Project RattleCam was founded as a camera trap project in 2021 and launched the first off-grid livestream on a den of wild Prairie Rattlesnakes (Crotalus viridis) in 2024. Both camera types captured hundreds of Prairie Rattlesnakes gathering in the summer as they prepared to give birth to pups before …

Effects Of Sediment Composition On Spartina Alterniflora And Juncus Roemerianus Productivity In Coastal Virginia: A Thin-Layer Sediment Placement Experiment, Caitlin Hemphill

Biological Sciences Theses & Dissertations

Climate change poses a major threat to the health of estuaries and their coastal wetland systems. The Chesapeake Bay’s coastal salt marshes are at high risk of inundation due to sea-level rise and land subsidence. Restoration techniques for maintaining coastal marsh resistance to sea-level rise are being developed and refined, with thin layer placement (TLP) emerging as a feasible solution in many areas of the United States. Despite TLPs use across the country, additional research is needed on species-specific responses, sediment types, and geographically focused studies in the lower Chesapeake Bay. My research addresses these gaps by combining both greenhouse …

Coal Mining Reclamation: Lessons Learned From Tropical And Subtropical Countries, Priyaji Agung Pambudi, Suyud Warno Utomo, Roni Setyo Handoko

Journal of Environmental Science and Sustainable Development

This study addresses the persistent environmental challenges associated with coal mining in tropical and subtropical regions, where complex microclimates and ecological variability hinder effective reclamation. Despite the increasing global coal demand, comparative cross-country insights remain limited. This research fills the gap by evaluating the best practices. This study employs a qualitative methodology with a comparative case study design, uses systematic literature review to evaluate ecology based reclamation policies and implementation practices. Data were sourced from peer-reviewed journals from Scopus and the Web of Science database and institutional reports, and analyzed using McHarg’s landscape ecology theory to evaluate reclamation policies, ecological …

Methodology For Environmental Toxicology: Assessing Feeding And Rearing Strategies In Largemouth Bass (Micropterus Nigricans) Larvae, Amber Hitchins, Hannah Mcneese, Deise Cruz, Andrew Todd, Maria Sepúlveda, Tyler Hoskins

Discovery Undergraduate Interdisciplinary Research Internship

Poly- and perfluoroalkyl substances (PFAS) are an anthropogenic group of chemicals known for their persistence in the environment and their potential to bioaccumulate. PFAS can bioaccumulate in largemouth bass (Micropterus nigricans), yet the effects of exposure on bass larvae are unknown. While largemouth bass are commonly raised for aquaculture, techniques for rearing bass which enable controlled experiments at known densities, a necessity for toxicity studies, are poorly understood. Furthermore, the live prey typically used in existing approaches are not suitable for PFAS studies due to high background concentrations. The objective of this project was to assess different venues …

Assessing The Ecological Drivers And Consequences Of Partial Migration In Hudson River Striped Bass Over Three Decades, Caitlin Egan Zimmer

Biology ETDs

Climate change and shifts in human land use have caused extensive impacts to the connectivity, structure, and resilience of aquatic populations. Partial migration (PM), where only some individuals from a population migrate while the rest remain resident, can mitigate population-level responses to environmental stressors. However, little is known of the underlying mechanisms promoting variation in migration and whether these shift over time. In the Hudson River Estuary, striped bass (Morone saxatilis) are known to exhibit anadromous PM behavior. Here, I measured carbon isotopes (δ¹³C) of essential amino acids in striped bass scales to determine variation in …

The Island Biogeography Of Mangrove-Dwelling Vertebrates: Isolation, Specialisation, And Extinction, Jian Xiong David Tan

Biology ETDs

Mangroves are highly dynamic ecosystems that are widely distributed across the coastlines of the tropics and subtropics. Despite their low plant diversity, mangroves host a disproportionately high number of terrestrial vertebrate taxa. However, mangrove specialists — taxa that only occur in mangrove habitats — exhibit a global distribution that is incongruous with the broader background distribution patterns of mangrove-associated fauna, exhibiting higher diversity in Australia and Southeast Asia. This dissertation therefore aims to assess how the diversity and distribution of mangrove specialist fauna may have been shaped by the historical biogeography of mangroves, and the effects of mangrove specialisation on …