Ecology and Evolutionary Biology Commons^™

Bearpaw Reserve Wildlife Monitoring And Mapping With The Wildlands Conservancy, Hope Hansen

Scripps Senior Theses

For my Environmental Analysis Capstone, I worked in a small group to monitor and map the wildlife at Bearpaw Reserve. Bearpaw Reserve, located in Forest Falls, California, is a 600 acre tract of wilderness that is owned by The Wildlands Conservancy. Bearpaw is located about an hour from Claremont, in the San Bernardino Mountains. The Wildlands Conservancy makes management decisions about its reserves while applying conservation research to the real world.

My group’s task was to use trail cameras to gather data on the wildlife at Bearpaw, then visualize this information into a GIS map. We used a combination of …

Effects Of Varying Biochar Concentrations On The Growth Of Lactuca Sativa (Newham Bibb Lettuce), Lauren Holler

Williams Honors College, Honors Research Projects

The objective of this research experiment was to investigate the effectiveness of using biochar in potting soil in terms of plant growth and soil quality. This experiment was carried out using varying amounts (0%, 5%, 10%, and 20%) of biochar in the soil to see its effect on seed germination, plant growth, and soil quality such as pH, water retention, and soil temperature. The aim of the experiment was to identify whether biochar can be used in soil to promote healthier and stronger plants. There were four treatments which included 0% (Control), 5% (Treatment 1), 10% (Treatment 2), and 20% …

Sexual Di(Et)Morphism: Using Experimental Evolution To Test Whether Resource Partitioning Promotes Divergence Of The Sexes In Drosophila Melanogaster, Owen A. Jamieson

Theses and Dissertations (Comprehensive)

Sexual dimorphism has been a long-studied phenomenon in the field of evolutionary biology. Usually, these differences in morphology, physiology and/or behaviour between the sexes are studied through the parsimonious lens of sexual selection. However, there are natural history cases where this lens does not seem applicable. Some species show sex specific morphological traits whose presence may not be due to a direct benefit to reproduction, but a difference in how each sex interacts with the environment and differing selective pressures from the environment on either sex. Darwin even brought up examples of this kind of dimorphism and pondered their existence, …

Sediment Redox-Driven Iron Flux And Phytoplankton Community Responses: Implications For Cyanobacterial Suppression And Functional Stability Across Boreal Lakes, Julia K. Kozak

Theses and Dissertations (Comprehensive)

Freshwater eutrophication contributes towards the development of cyanobacterial harmful algal blooms (cHABs), but nutrient availability alone does not fully explain variation in phytoplankton community composition or physiological performance. While phosphorus (P) availability has been known to regulate phytoplanktonic biomass, iron (Fe) is an important micronutrient supporting Fe-heavy processes within cyanobacteria (i.e., nitrogen fixation and photosynthetic electron transport). Sediment Fe availability in freshwater ecosystems is regulated by reduction oxidation (redox) conditions at the sediment-water interface (SWI), where nitrate (NO₃^-) has been found to maintain oxidizing conditions and prevent the reduction of Fe(III) to more readily bioavailable soluble Fe(II), …

Leveraging Mammal Mycophagy To Determine Environmental Drivers Of Truffle Diversity, Brittany Hartsock

Electronic Theses and Dissertations

Many mycorrhizal fungi are hypogeous (truffle-forming), producing underground fruiting bodies. Studying truffles is inherently challenging due to their hidden nature. However, mycophagous mammals provide a unique opportunity to study hypogeous fungi because they rely on truffles as a food source. Although several truffle species have recently been described in the southern Appalachian region, their fruiting patterns remain poorly understood. To address this, we quantified truffle richness and spore loads from 670 Peromyscus scat samples collected across 42 sites spanning an environmental gradient during 2024 in the Blue Ridge Mountains of East Tennessee. We found that truffle richness and spore abundance …

Geographic And Environmnetal Influences On Color Pattern Similarity Between Coral Snakes (Genus: Micrurus) And Their Lookalikes, Anthony Sena

Dissertations

Venomous coral snakes and their lookalikes are often regarded as a classic example of Batesian mimicry, whereby a harmless species imitates a harmful species. The existing literature regarding coral snake resemblance presents a divisive stance on whether Batesian mimicry is the primary driver of shared color patterns or if alternative factors are responsible. While recent literature largely favors the Batesian hypothesis, empirical support remains inconsistent, and the specific geographic and interpretation of the conditions required for mimicry lacks consensus within the scientific community.

To evaluate the mechanisms maintaining these phenotypes, a quantitative, multivariate framework was utilized to analyze 400 museum …

Infrared Detectability Of Whale Species And Behaviors To Enhance Automatic Detection For Real-Time Vessel Strike Avoidance, Laura J. Howes

Graduate Masters Theses

Real-time detection of large whales at sea is critical for mitigating serious injury and mortality from ship strikes and other human activities such as seismic surveys, especially for endangered species such as the critically endangered North Atlantic Right Whale (Eubalaena glacialis). Traditional marine mammal observers are limited by environmental conditions and human factors, necessitating a robust, 24-hour solution. This study investigates the efficacy of a novel onboard detection tool infrared (IR) technology to detect whale blows and body parts. While IR is a promising advancement, its performance under varying sea conditions (e.g., fog, humidity) and its ability to …

Exploring Foundations Of Animal Host-Microbe Interactions In A Freshwater Sponge, Jacob S. Pawley

Electronic Theses and Dissertations

The most ancient eukaryotic immune defense mechanisms evolved in unicellular species. Multicellular eukaryotes, however, expanded these mechanisms to meet challenges unique to multicellular life, including barrier formation, long-distance cell signaling, and coordinated responses that eliminate microbial threats while minimizing damage to the host. As such, animal immune signaling pathways are exceptionally intricate and diverse. Though, most of what is understood about animal host–microbe interactions stems from a small handful of model systems. Here, I evaluate host–microbe interactions and innate immunity in sponges using the highly tractable freshwater sponge, Ephydatia muelleri. I report the discovery of an external host-derived matrix …

Understanding The Impact Of Environmental Change On Shorebird Abundance And Distribution Across The Intermountain West Over The Past 30 Years, Sharon Montecino

All Graduate Theses and Dissertations, Fall 2023 to Present

Shorebirds have declined worldwide over the past century, mainly due to wetland loss and degradation. Wetlands are sites that are temporarily or permanently flooded and provide critical habitat for shorebirds, especially in arid and semi-arid regions such as the Intermountain West. However, climate change and human water use threaten these wetlands, and how these threats may affect shorebirds in this region remains poorly understood. In the early 1990s, shorebird counts at over 160 wetlands across the Intermountain West provided a broad assessment of shorebird populations in the region. These counts remained the only large-scale surveys until 2022, when the Intermountain …

Secure Agricultural Futures: Re-Defining And -Imagining Agricultural Water Landscapes In The Us West, Britta L. Schumacher

All Graduate Theses and Dissertations, Fall 2023 to Present

Aridity is swiftly becoming the US West’s new normal. As agricultural communities adjust to persistent growing-season scarcity, they find their livelihoods under increasing threat. This points to the urgency of finding paths toward more secure water futures. A piece of this future puzzle includes water (re-)distribution – taking excess from one place and delivering it to another in need. To begin thinking about (re-)distribution, this dissertation engages with three mixed-methods and multiscale studies. The first study pairs county-level data across the 11 westernmost US states with survey data collected from individual producers in Utah to assess past and current trends …

From Genes To Streams: Mitochondrial Approaches To Population Monitoring Of The Santa Ana Sucker Catostomus Santaanae, Mariana Antonio

Electronic Theses, Projects, and Dissertations

This study was developed to use aquatic environmental DNA (eDNA) as a tool to detect the presence of the Santa Ana sucker (Catostomus santaanae), a federally threatened fish species, across the Santa Ana River in Southern California. Environmental DNA is any genetic material that an organism sheds into the environment. We can get an idea of what aquatic species are present when sampling water at a given site. We sequenced the complete mitochondrial genome (mitogenome) of the Santa Ana sucker and designed custom DNA primers to improve eDNA detection accuracy. These primers were selected based on high genetic …

Spatial And Hydrologic Effects Of Climate Change And Urbanization On Freshwater Fish Communities In North Georgia Watersheds, Mayuko Mizutani

Master's Theses

Urbanization and climate change are altering streamflow and land cover across the southeastern United States, threatening freshwater biodiversity in rivers already burdened by impoundments and habitat loss. I investigated how changes in streamflow and land cover might affect fish community biodiversity in the Etowah River watershed of North Georgia. By combining a dataset of fish collections from 1999 through 2019 with contemporaneous land use and daily streamflow, I was able to model fish community responses to urbanization and climate-driven hydrologic changes and then forecast fish community structure under multiple CMIP6 global climate models and greenhouse gas emissions scenarios (SSP2-4.5 and …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

Determining The Role Of Maumee River Sediments In Microbial Nitrogen Transformations And Net Fluxes, Ashlyn Stanalonis

Master's Theses

The Maumee River watershed is the largest of any river feeding into the Laurentian Great Lakes and is primarily comprised of agricultural land uses. Most cultivated crops require fertilizer applications to sustain growth and productivity. Fertilizer runoff is a major source of nutrient loading to the river, and total nitrogen (N) and phosphorus (P) inputs contribute to eutrophication and cyanobacterial blooms in the western basin of Lake Erie. This study aimed to characterize Maumee River sediments as net N sinks or sources to the western basin and evaluate N removal efficiency (a valuable ecosystem service) to determine if river sediments …

Paleolimnology And Diatom Taxonomy From Lake Tanganyika, Sristika Adhikari

All-Inclusive List of Electronic Theses and Dissertations

Lake Tanganyika is one of the world's largest freshwater ecosystems, supporting rich aquatic biodiversity and providing several ecosystem services to surrounding communities. Environmental changes such as rising lake surface temperatures, pollution, and land-use alterations threaten the lake’s sustainability. This research examines spatial and temporal variations in nutrient dynamics and primary productivity of Lake Tanganyika using diatom assemblages from multiple locations. Our findings indicate reduced nutrient levels and longer stratification periods in the lake’s central basin during most of the Common Era, as indicated by a remarkable increase in the relative abundance of long, needle-shaped planktonic Nitzschia species. In the southern …

Integrating Space Use And Demography To Support Management Of An Endangered Alpine Ungulate, Danielle J. Berger

All Graduate Theses and Dissertations, Fall 2023 to Present

The places animals choose to live affect the food they find, the dangers they face, and the weather conditions they experience. These experiences influence whether individual animals survive and reproduce, which in turn affects the size and health of animal populations. Although scientists have long believed that animal movements play an important role in population trends, there has been limited real-world evidence showing this connection. Advances in GPS tracking technology now allow researchers to follow animals over long periods and better understand how movement influences survival. Using 20 years of GPS tracking data from the endangered Sierra Nevada bighorn sheep …

Carbon Cycling, Salinization, And Long-Term Water Quality Trends In Rocky Mountain Streams, Allyson J. Marrs

All Graduate Theses and Dissertations, Fall 2023 to Present

Humans have greatly affected streams and rivers worldwide through urbanization, agriculture, and water use. The purpose of my dissertation is to increase our understanding of various human impacts on rivers. In chapter two, I aim to determine whether there are differences in greenhouse gas (GHG) emissions between a natural river and manmade canals. I did this by measuring the emissions and dissolved concentrations of three of the most prevalent GHGs, carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). I found that most of the sites I studied were emitting CO₂ and CH …

Regional Occurrence And Spatiotemporal Habitat Partitioning Of The Culex Genus Mosquitoes In Salt Lake City And Uintah Basin, Utah, Katelyn Graybeal

All Graduate Theses and Dissertations, Fall 2023 to Present

West Nile virus is the most common mosquito-borne disease in North America and can cause serious illness, including inflammation of the brain and nervous system. Because there is currently no widely available vaccine for humans, preventing mosquito bites and monitoring mosquito populations remain the most effective ways to reduce disease risk. Understanding which mosquito species are present, where they occur, and how they respond to environmental change is critical for protecting public health.

This research examined the mosquito species responsible for spreading West Nile virus in Utah through two complementary studies. The first study focused on the Uinta Basin in …

The Influence Of Habitat And Individual Specialization On Mountain Lion (Puma Concolor) Hunting Strategy In A Multi-Prey System, Hannah B. Klugman

All Graduate Theses and Dissertations, Fall 2023 to Present

There is a growing recognition that animal species considered generalists (having a broad and varied diet), are actually specialists, a collection of individuals with different preferences and strategies known as specializations. The diet of a specialist depends on the variety and quantity of available food options, and their own ability to take what they need. Mountain lions (Puma concolor) are known for their ability and tendency to hunt large prey, such as elk (Cervus canadensis) and mule deer (Odocoileus hemionus), but despite the fact they overlap with other potential large prey, like feral horses …

Behavioral And Landscape Factors Affecting The Effectiveness Of Egg-Bait Management For Common Ravens In The Great Basin, Usa, Sierra L. Pederson

All Graduate Theses and Dissertations, Fall 2023 to Present

Common Ravens have become increasingly common across the Great Basin of the western USA, largely because human activities, such as roads, agriculture, livestock operations, and human-made structures, provide them with abundant food, water, and nesting sites. As raven numbers have grown, so has their impact on vulnerable species like the greater sage-grouse. Like many other ground-nesting species, greater sage-grouse eggs and chicks are especially susceptible to predation. To help reduce raven numbers in sensitive areas, wildlife managers often place hard-boiled chicken eggs treated with a toxin (DRC-1339) on the landscape, expecting that ravens will die after eating these eggs and …

Eusocial Caste Specialization Under Abiotic And Biotic Stress In A Stingless Bee, Tetragonisca Angustula, Kristin M. Robinson

Dissertations

Eusocial insects rely on division of labor to achieve high colony efficiency and provide essential ecosystem services, but specialization may also constrain colony resilience when workers operate near their physiological or behavioral limits under abiotic and biotic stressors. How specialization mediates these responses remains poorly understood, particularly in stingless bees (Tribe: Meliponini). Using the agriculturally relevant stingless bee Tetragonisca angustula, which possesses a specialized soldier subcaste, I investigated how a high degree of worker specialization influences physiological tolerance and predator responses across worker subcastes.

In this dissertation, I quantified variation in thermal tolerance and desiccation resistance among worker subcastes …

Silviculture For Coastal Forest Resilience: Promoting Forest Regeneration And Managing Invasive Plant Species, Ryan Bohannon

All Dissertations

Coastal forests of the southern United States and the ecosystem services they provide are threatened by an intensifying and interacting suite of disturbances associated with global change. Silvicultural strategies such as enrichment planting, invasive plant management, and browse mitigation treatments can enhance the resilience and adaptive capacity of forests to these threats by promoting sustainable regeneration and recruitment dynamics. To improve our understanding of coastal forest disturbance regimes and their impacts on forest stand dynamics, I conducted a systematic literature review of maritime forest disturbance ecology and identified coastal storms, ungulate browsing pressure, and invasive plants as primary disturbances shaping …

Lizards In The Trees: Structural, Functional, And Behavioral Specializations To A High-Risk Environment, Victor D. Munteanu

All Dissertations

Animals must contend with unexpected changes in their habitat and environment to thrive. Arboreal habitats can consist of a wide variety of environmental features, and failure to adequately contend with these features can result in high risk of injury or death upon falling. Despite these strong selective pressures, many vertebrate lineages have successfully invaded arboreal habitats. Using lizard taxa as a model system, I investigated how morphology and behavior have evolved within this specific habitat transition. I pursued these investigations through complementary analyses including: 1) evaluating the effect of stance height and tail prehensility on perturbation recovery, 2) assessing behavior …

Effects Of Urbanization On Barrier Island Bobcats, Meghan P. Keating

All Dissertations

Urbanization is a leading driver of ecological change and presents unique challenges for carnivores by altering habitat availability, prey communities, and exposure to anthropogenic threats. Although many carnivore species persist in developed landscapes, the ecological and demographic consequences of urbanization often remain poorly understood, particularly over long timescales. Using one of the longest-running studies of a free-ranging carnivore population, I evaluated the effects of urbanization on the behavior, resource use, exposure risk, and population dynamics of bobcats (Lynx rufus) inhabiting a residentially developed barrier island in coastal South Carolina, USA. I first examined temporal and spatial responses to …

The Past, Present, And Future Of Climate Adaptation In A Widespread Lizard Species, Matthew R. Mcternan

All Dissertations

Climate, as a selective force, shapes patterns of biodiversity globally. However, how species adapt to climate remains a central question of biology. The need to understand climate adaptation is paramount, as global climate change threatens a large portion of global diversity. Climate can impose selection on life by either controlling rates of energy intake and expenditure through effects on body temperature and activity, or by exposing organisms to conditions beyond their physiological limits. Studies of climate adaptation have identified a wide-range of putatively adaptive phenotypic patterns, but genomic evidence is increasingly being used to investigate these patterns and better understand …

Prenatal Acoustic Programming Of The Developing Hypothalamus: A Multi-Omic Analysis Of Heat Call Exposure In Zebra Finch Embryos, Prakrit Subba

All Dissertations

Climate change is intensifying thermal stress on wildlife globally, yet the developmental mechanisms by which embryos use prenatal cues to adjust to predicted environments remain unclear. In Australian zebra finches (Taeniopygia guttata), incubating parents produce distinctive heat call vocalizations at high ambient temperatures, and embryos exposed to these calls during late incubation develop altered growth trajectories, thermoregulatory capacity, and reproductive outcomes, suggesting a form of anticipatory developmental programming triggered by sound alone. To investigate the molecular basis of this response, I initially hypothesized that prenatal heat call exposure would act primarily through hypothalamic neuroendocrine reprogramming, given the central …

An Analysis Of Mating Strategies In Rotifers Inhabiting Temporary Habitats, Ariel Bollinger

Open Access Theses & Dissertations

Reproduction is critical for organisms inhabiting ephemeral aquatic habitats where desiccation risk favors rapid and successful mating. Monogonont rotifers rely on sexual reproduction to produce diapausing eggs that withstand harsh conditions. I investigated how mating behaviors vary among populations of five rotifer species based on the hydroperiod of their habitat: Epiphanes brachionus and E. chihuahuaensis were sampled from habitats with short (SH) and long (LH) hydroperiods; Euchlanis dilatata was collected from a short (SH) and a permanent habitat; and Plationus patulus and Sinantherina socialis were collected from a long (LH) and a permanent (Perm) habitat. I hypothesized that SH populations …

Long-Term Spatiotemporal Change In Coral Reef Fish Populations And Communities In The Philippines, John Christopher Whalen

Biological Sciences Theses & Dissertations

The Visayas Region of the Philippines is a global epicenter of marine fish biodiversity. Hypotheses attribute this peak of species richness within the Coral Triangle to processes that occur at geological time scales. However, changes in biodiversity may occur on ecological time scales, allowing for the assessment of the potential impact of anthropogenic activities. Recent declines in genetic, species, and ecosystem diversity have been observed in the tropics, including the Philippines. Within the Philippines the Visayas Region is considered the epicenter of species adversity due to anthropogenic stressors such as habitat degradation, overfishing, and harvesting individuals for the aquarium trade. …

From Shallow To Upper Mesophotic Reefs: Examining Environmental Influences On Coral Physiology And Thermal Tolerance, Katherine Eileen Parker

Biological Sciences Theses & Dissertations

Coral reefs are increasingly threatened by rising ocean temperatures, yet coral thermal tolerance varies widely across species, populations, and environments. This dissertation investigates the biological and environmental mechanisms underlying coral thermal resilience, with a focus on symbiosis dynamics, photoacclimation, and the interaction between light and heat stress across environmental gradients. Specifically, it examines how coral-Symbiodiniaceae partnerships respond to thermal stress using the Coral Bleaching Automated Stress System (CBASS) across contrasting thermal and light environments, spanning population-level differences, depth-associated variation, and experimental manipulation of light during acute heat stress. First, thermal thresholds and transcriptomic dynamics were examined in two wild Porites …

Evaluating Fish Assemblages At An Early-Stage Living Shoreline Project In Lake Pontchartrain, Collin Glaser

LSU New Orleans Theses and Dissertations

Living shorelines are an increasingly popular restoration approach for reducing erosion while improving habitat quality. The Bucktown Living Shoreline Project is a large-scale restoration effort along the southern shore of Lake Pontchartrain aimed at enhancing coastal resilience and restoring historic marsh habitat. This thesis evaluated early fish assemblage response to the Bucktown Living Shoreline Project over one year and placed those assemblages within the broader historical context of Lake Pontchartrain. Monthly sampling was conducted at the living shoreline and an adjacent riprap control site using seines, cast nets, and minnow traps. Fish assemblage structure was not significantly different between sites. …