Digital Commons Network^™

Foraging Plasticity And Mercury Contamination In Red-Legged Kittiwakes: A Multiple Stressor Perspective, Sam E. Clay

All-Inclusive List of Electronic Theses and Dissertations

Arctic seabirds are facing increasing stress from climate change, yet the interactive effects of multiple stressors on behavior remain poorly understood. Adopting a multiple stressor perspective promises to advance understanding of avian behavioral responses to climate change, as climate change is exposing Arctic and subarctic animals to a complex set of stressors rather than a single stressor in isolation. Using the red-legged kittiwake (Rissa brevirostris) as a model, I examined how multiple stressors, including mercury (Hg) exposure, shifting wind conditions, and varying foraging conditions linked to sea surface temperature (SST) may interact to constrain behavioral plasticity and energetically expensive behavior …

Microplastic Composition And Exposure Pathways In Freshwater Systems: A Multi-Matrix Comparison Between Streams And Retention Ponds In Hamilton County, In, Mya Whaley

All-Inclusive List of Electronic Theses and Dissertations

Since the early 1900s, the use of plastics has increased exponentially. The breakdown of plastic materials has exposed all ecosystems to microplastics (small particles of plastic < 5 mm), which are now ubiquitous in natural settings. Microplastics have a relatively large surface area, and many chemicals adsorb to these small particles, impacting their fate and transport of pollution. While microplastics have been found in virtually every setting on Earth, research is necessary to understand their impact on freshwater ecosystems and biogeochemical cycles. The focus of this research was to investigate microplastic compositions in crayfish, sediments, and water samples collected in streams and retention ponds. We analyzed trends in microplastic counts across different land-cover classes, waterbody types, and species, and compared concentrations among matrices to improve our understanding of microplastic exposure pathways in freshwater ecosystems. As a secondary objective, lead and arsenic concentrations were analyzed from sediment samples to investigate metal burdens and compare them to microplastic concentrations. Our findings revealed that, in general, urban streams had the highest microplastic concentrations within land cover categories, and retention ponds had higher microplastic counts than streams. Crayfish, such as F. rusticus had higher microplastic concentrations than F. virilis and F. propinquus, although these results may be influenced by study design. The most common microplastic type was fibers, and most common color was transparent. There was no significant correlation between microplastic and metal concentrations in sediments. We found crayfish to be adequate bioindicators of microplastic pollution, because they were less impacted by environmental variability than sediment and water samples. This research presents the first evidence of microplastics in our study species, F. propinquus, F. rusticus, and F. virlis. This work presents new evidence of microplastic accumulation in crayfish, sediments, and water from freshwater systems in the Midwestern United States. Microplastics were found in every sample type—crayfish, water, and sediment—across urban, rural, and forested landscapes, highlighting their pervasive distribution. The findings provide foundational data for assessing emerging ecological and human-health risks and emphasize the importance of sustained monitoring and research on MP contamination in freshwater environments.

Preserving The Past: Exploring The Last Frontier's Ecosystem Shifts And Biodiversity Of The Tallgrass Prairies, Gisell Maldonado, Amelia Villaseñor

Anthropology Undergraduate Honors Theses

In North America, grasslands are a cornerstone of the environment. Historically, the tallgrass prairie was expansive and reached from Manitoba in Canada to Texas. Today this unique ecosystem is highly fragmented and reduced, but it remains an important ecosystem for biodiversity and cattle management. While there are many complex ecological interactions in the prairie, recent research shows that large herbivores are vital in maintaining grasslands through grazing and other behaviors that reduce woody encroachment and support nutrient cycling. Here, we examine cow and bison dietary behaviors and connect these to the ecosystem services provided by these large herbivores. In the …

The Beat Behind The Bark: Investigating The Effects Of Music Tempo On Canine Physiological And Psychological States, Marley Lanier

Poster Presentations

Music is a universal component of human culture that has been demonstrated influencing emotional, cognitive, and physiological responses, specifically heart rate and hormonal responses (Mehr et al., 2019; Trappe, 2012). Recently, this research has expended to explore how music may affect non-human animals, particularly dogs, due to their roles as therapy animals, service animals, and human companions (Lindig et al., 2020; Gee et al., 2021). Being able to understand how music influences canine stress and relaxation hold important applications in environments such as shelters, veterinary clinics, and at home. One important feature of music is tempo, or beats per minute …

Acute Effects Of The Psychoactive Pollutant Fluoxetine On The Antipredator Behavior Of The Gulf Killifish (Fundulus Grandis), Semyra Reus

Honors Theses

Pharmaceutical contaminants are increasingly prevalent in aquatic environments, yet their sublethal effects on ecologically relevant behaviors remain poorly understood, particularly in estuarine systems. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, are of particular concern due to the conserved role of serotonin in regulating behavior across vertebrates. Here, we investigated how acute exposure to environmentally relevant concentrations of fluoxetine influences anti-predator behavior in Gulf killifish (Fundulus grandis), a key estuarine fish commonly found in saltmarsh habitats. Killifish were exposed to control (0 ng/L), low (17.8 ng/L), and high (596 ng/L) fluoxetine concentrations and subsequently tested in the presence …

The Role Of Floodplain Connectivity In Shaping The Abundance, Size-Class Distribution, And Schooling Behavior Of The Associated Fish Assemblage, Adam H. Quade

LSU New Orleans Theses and Dissertations

The life histories of many Louisiana fishes are closely tied to the timing, magnitude, and duration of the Mississippi River flood pulse, which regulates the ecological connectivity and productivity of adjacent floodplain habitats. Anthropogenic modifications such as levee construction and water-control structures have disrupted these natural hydrologic linkages, altering habitat quality and community structure across the Lower Mississippi River Basin. This dissertation used high-resolution imaging sonar to investigate how fish assemblages, species, and collectives respond to changes in floodplain connectivity within the Richard K. Yancey Wildlife Management Area prior to hydrologic restoration. In the first chapter, I applied imaging sonar …

Morphological Variation Of Lingual Glands In Wild American Alligator (Alligator Mississippiensis) Populations, Benjamin Angalet

Master's Theses

American alligators (Alligator mississippiensis) inhabit diverse aquatic ecosystems including freshwater wetlands, swamps, and estuarine rivers. As apex predators, their physiological resilience has implications for ecosystem stability and long-term conservation. With projected sea-level rise and increasing saltwater intrusion into coastal freshwater habitats, understanding the osmoregulatory capacity of alligators is increasingly important. Unlike marine-tolerant crocodilians such as the saltwater crocodile (Crocodylus porosus), which possess specialized salt-secreting lingual glands in addition to renal and cloacal mechanisms, the morphology and physiological significance of lingual glands in wild American alligators remain poorly understood. This study examined lingual gland morphology and plasma …

Contrasting Roles Of Downed Wood And Leaf Litter In Structuring Aphaenogaster Ants And Other Forest-Floor Arthropod Communities, Danielle E. Dolan

Great Lakes Center Masters Theses

Forest floors are dynamic and spatially heterogenous landscapes characterized by differing amounts of light, temperature, and moisture. Bounded substrates, like downed wood and leaf litter, add further complexity to this landscape. Specifically, downed wood is noted for its ability to retain a higher moisture level than the surrounding environment, and as such can serve as an ideal microhabitat for desiccation intolerant organisms (e.g., salamanders and eusocial insects). Here, I attempt to disentangle the relationship between forest floor arthropods and microhabitat selection (i.e., downed wood vs leaf litter) on a northeastern forest floor. The ant, Aphaenogaster picea, was chosen as my …

Bugs, Birds, Blue: Queer Ecologies Of Embodiment, Kinship, And Survival, Celeste B. Newcomb

Theses and Dissertations

bugs, birds, blue is a multi-channel audiovisual installation that examines queer ecology as a framework for understanding transgender embodiment, kinship, and survival amid environmental crisis and ongoing political attacks on trans life (Mortimer-Sandilands and Erickson). Through sculpture, projection, sound, reflective surfaces, and biological imagery, the installation places human bodily matter alongside microbial and aquatic life forms to challenge narratives that frame trans existence as unnatural, recent, or isolated. Instead, the work proposes transness as relational, adaptive, and deeply entangled with broader ecological systems. The installation is composed of two interconnected environments. On one side of the space, three aquariums rest …

The Hitchhiker's Guide To The Host: Fleas And The History Of Pikas In North America, Josh Pletcher

All NMU Master's Theses

Parasite phylogenetics can offer windows into the cryptic evolutionary history of hosts, often highlighting events that are not recorded by the phylogenetics of the host. Pikas (small lagomorphs) host a diverse parasite community comprising endoparasites (e.g., coccidians, nematodes, and cestodes) and ectoparasites (e.g., fleas and mites). Phylogenetic analysis of pika endoparasites has revealed pikas evolved in Asia and colonized North America in two waves, and that contact between these two pika lineages allowed parasites to be transferred from one lineage to another and to survive the extinction of their original host. To uncover these cryptic histories, understanding the biogeography of …

Population Structure And Connectivity Of Atlantic Nurse Sharks (Ginglymostoma Cirratum) In The Bahamas And Outlying Areas, Baylie A. Fadool

School of Natural Resources: Dissertations, Theses, and Student Research

Understanding animal ecosystem dynamics and behavior at the individual and population levels is essential for identifying life-history patterns and important areas for management and conservation. Marine fish species often face minimal geographic barriers to movement, but environmental (temperature, salinity, current) or intrinsic barriers (philopatry, site fidelity) can dictate gene flow. Atlantic nurse sharks (Ginglymostoma cirratum) are an International Union for Conservation of Nature (IUCN) listed ‘vulnerable’ species and present a unique opportunity to investigate patterns of population structure and connectivity in large-bodied sharks. They are benthic and display reproductive philopatry, with recent work suggesting they have the capacity …

Gaining Mussel: Evaluating Reintroduction Success Of Native Freshwater Mussels In Nebraska And Eastern Wyoming, Travis A. Moore

School of Natural Resources: Dissertations, Theses, and Student Research

Freshwater mussels are one of the most imperiled groups of organisms in North America, with over two-thirds of species considered threatened, endangered, or of special concern. These long-lived bivalves are essential to stream ecosystems, acting as filter feeders that improve water quality and as indicators of aquatic health. In Nebraska and Wyoming, native mussel populations have declined sharply due to habitat modification, pollution, and reduced connectivity. Two species of particular concern are the Plain Pocketbook Lampsilis cardium, listed as Tier I at-risk in Nebraska, and the Fatmucket Lampsilis siliquoidea, a Tier II at-risk species. In response, state agencies …

Characterizing The Molecular Response Of Embryonic Zebra Finch To Acute Sound Playback, Saidat O. Adeniran-Obey Miss

All Theses

Auditory stimuli are important cues that influence developmental plasticity in animals and are important for development and adaptation to an ever-changing environment. In the zebra finch (Taeniopygia guttata), there is evidence of adaptive developmental reprogramming in response to a prenatal ‘heat call’. Embryos exposed to this heat call exhibit changes in growth rate post-hatch, increased heat resistance, and enhanced reproductive success at maturity. However, it has long been assumed that embryonic zebra finches cannot respond to sound due to the immaturity of their auditory system. These findings raise the critical question of whether late-stage zebra finch embryos can, …

Ontogeny And The Effects Of Perinatal Stress In The First Immature Skeleton Of Teleoceras Aepysoma (Perissodactyla, Rhinocerotidae), Joe Gajewski

Electronic Theses and Dissertations

Recovery of an immature fossil rhinoceros (Teleoceras aepysoma) skeleton (ETMNH 32999) from the Gray Fossil Site in Tennessee offers the first insights into the ontogeny of the species. ETMNH 32999 is interpreted to be a subadult male in an age class equivalent to ~17-20% of potential lifespan. Comparative analyses support the hypothesis that subadults of related taxa are typically ~91% of average adult size in most dimensions. However, certain cranial dimensions are substantially lower than expected in ETMNH 32999, averaging only ~74% of the average conspecific adult. Such departure from typical growth rates is suggested to be attributable …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

Ecological Responses To Living Shoreline Restoration, Aaron S. Bland

Graduate Theses and Dissertations (2019 - present)

Coastal built communities and natural coastal ecosystems face similar and interrelated hazards: shoreline sediment erosion, shoreline retreat, and worsening storms, each of which is exacerbated by relative sea level rise. Living shorelines are coastal defense projects that incorporate natural habitats to provide more sustainable shoreline defense and improve the coastal ecosystem. Living shorelines have been widely adopted, but their performance has been highly variable, and the mechanisms of project success and failure are unclear. The overarching goal of this dissertation was to better understand the ecosystem responses to coastal restoration, focusing on the primary habitats of coastal salt marsh and …

Feeding Ecology In Coastal Systems, Randi L. Cannon

Graduate Theses and Dissertations (2019 - present)

Oysters (Crassostrea virginica) are critical foundation species in estuaries, providing numerous ecological and economic benefits. However, oyster populations have diminished worldwide. Effective oyster restoration and aquaculture require a mechanistic understanding of the physiological and environmental factors that govern oyster feeding, growth, and resilience under changing coastal conditions. We investigated how oyster ploidy and environmental conditions influenced oyster feeding and investigated how changes in abiotic conditions affected behavioral performance of oyster drills (Stramonita spp.), a key oyster predator. To better understand feeding responses and behaviors of both predator and prey we 1) used in-situ filter feeding assays to determine if feeding …

Enhancing Walleye (Ogaa) Recruitment: Evaluating Assisted Reproduction As A Mitigation Strategy, Douglass Keiser

Biology Graduate Theses

Over the past several decades, cold- and cool-water fish populations across the Upper Midwest, including Minnesota and Wisconsin, have shown troubling signs of decline. Among the most affected is the walleye/Ogaa (Sander vitreus), a species deeply embedded in the ecological balance, cultural identity, and economic vitality of the region, and central to the lifeways, treaty-reserved rights, and resource stewardship of Tribal Nations, including Ojibwe communities across the Upper Midwest. Despite ongoing stocking efforts and harvest regulations, many lake systems have experienced persistent declines in natural recruitment, prompting resource agencies to investigate the underlying causes. One such system is …

Bats And Bacteria: Infection Dynamics At The Human-Wildlife Interface, Isabella Katherine Deanglis

Graduate Theses and Dissertations

As the second most diverse mammalian order, bats host an array of pathogens, some of which are known to infect humans. Synanthropic bats share spaces with humans, resulting in bat-borne pathogen exposure. While most bat-borne disease research has focused on viral pathogens, bats host numerous bacterial pathogens with zoonotic potential. By integrating a global meta-analysis with field studies in Sub-Saharan Africa, I characterize the structural attributes that facilitate shared interfaces, the bacterial pathogens present in synanthropic bats of rural Kenya, and the physiological and environmental dynamics influencing odds of infection in these synanthropic bats. Finally, I evaluate the clinical relevance …

Metabolomics In The Dryland Critical Zone: The Role Of Soil Metabolites In Phosphorus Acquisition, Kalpana Kukreja

Open Access Theses & Dissertations

Earth's Critical Zone (CZ) plays a key role in sustaining life through carbon, water, and nutrient cycling from the top of the canopy to the groundwater. A key feature of critical zone research is the integration of multiple interdisciplinary techniques. An emerging set of techniques that can add to this approach is the field of metabolomics, the quantification and study of comprehensive metabolite profiles. In this dissertation, I apply metabolomics to address knowledge gaps in dryland critical zone ecosystems, specifically how soil metabolite dynamics influence biogeochemical processes, and with a particular emphasis on phosphorus (P) cycling in the Chihuahuan Desert. …

From Soils To Plants And Back Again: The Effects Of Small Mammals On Arctic Ecosystem Processes, Andrew Uccello

Open Access Theses & Dissertations

Herbivores are essential drivers of above and belowground processes in ecosystems across the globe. Through their effects on ecosystem processes, herbivores represent a critical force shaping ecosystems undergoing rapid environmental changes, such as the Arctic. However, there are critical gaps in our knowledge of herbivores as drivers of Arctic ecosystem processes, especially concerning the role of small mammal herbivores. While previous research has made significant strides in identifying the role of small mammal herbivores as both top down and bottom up forces in Arctic ecosystems, we still lack an understanding that explicitly connects plant and soil responses to herbivory, especially …

Sex Or Survival: Does Wounding Elicit A Somatic Reproductive Tradeoff In Narnia Femorata Males?, Lillian E. Burbulis

Departmental Honors & Graduate Capstone Projects

Animals must partition resources into different life history traits resulting in tradeoffs because resources are finite. A tradeoff is the allocation of resources to one trait over another. Theory states that energy is allocated in a hierarchical fashion. For example, somatic maintenance should be a higher priority than reproduction, resulting in more resources being allocated to somatic maintenance compared to reproductive traits. The metabolic investment hypothesis states that energy must follow a hierarchical order prioritizing somatic maintenance over reproduction. Another hypothesis for energy allocation is the terminal investment hypothesis. This hypothesis states that energy will be allocated to reproduction over …

The Spatial Distribution Of Coccidia In Arkansas Freshwater Snails, Julia R. Pye, Taylor M. Fiedor, Jason M. Post, Kyle D. Gustafson

Create@State

Coccidia are obligate, intracellular parasites that infect the digestive tracts of many animals and cause coccidosis, which can result in vomiting, diarrhea, and in severe cases, death. At broader scales, the disease contributes to substantial economic losses in agriculture. Our study examined the distribution of Pfeifferinella ellipsoides, a coccidian parasite in freshwater snails. Based on previous research, we hypothesized that (1) there will be statistically significant spatial clustering in northern Arkansas and (2) the parasite will be found exclusively in two snail genera, Physa and Planorbella. We sampled 17 snail species and surveyed feces for oocysts from 1,920 snails and …

How Pollinator Populations Can Impact Chronic Disease Risk, Kylee Cubbison

Honors Projects

This project investigates how pollinator populations can impact chronic disease risk. Pollinator populations are declining, which can have serious implications for human health. Declining pollinator populations can limit healthy food production and affordability. Poor nutrition is a major risk factor for most chronic diseases. Less healthy food available for people to consume can negatively impact diets and increase the risk of developing chronic diseases. This project aims to address a potential gap in research existing on this specific topic regarding pollinator populations and human chronic disease risk. A brochure targeted towards educating the general public on this topic was created …

Aggression And Fish Welfare: Challenges And Opportunities, Christine M. Soper, Peter D. Dijkstra

Animal Sentience

Oldfield & Bonano’s (2024) [O&B] target article discusses the wellbeing and sociality of bony fishes. Many fish species, such as cichlids, are not only social but territorial. Aggression is normal, but territorial aggression in a captive environment can have a negative impact on welfare. Aggression-related injuries and deaths are prevalent in pet stores as well as research settings. We discuss the need to develop effective methods to minimize the negative consequences of aggression.

New Ways To Address The Plastic Problem, Andrew J. Hanna

The Penguin Review

Since 1950, the world has produced some 9.2 billion metric tonnes of plastic.1 Other sources place the total closer to ten billion metric tonnes Furthermore, nearly 500 million tonnes of new plastic are manufactured each year– a figure that's projected to increase to 1.2 billion tonnes by 2060.2 The environmental effects of all this plastic production and pollution are disturbing. Because most plastics are synthetic–meaning they contain "no molecules found in nature"– they can't decompose. Instead, they just break down into smaller and smaller pieces, becoming microplastics (less than five millimeters (5 million nanometers) across) and then nanoplastics (less than …

Skin Pattern As A Potential Monitoring Tool For Frog Populations, Lídize Sagarnaga Rivera, Virginie Rolland Dr., Lorin Neuman-Lee Dr.

Create@State

Skin pattern as a potential monitoring tool for frog populations

Population monitoring, which requires identifying individuals, is crucial for species conservation. Common techniques involve marking, which can harm animals and alter their behaviors. Natural markings are an alternative not yet explored for amphibians. Yet, the traditional method with elastomers (fluorescent implants) is invasive and not completely reliable—the tag may become lost or hard to see. The American green tree frog (Dryophytes cinereus) possesses naturally occurring and distinct golden dots on their dorsal side.  Therefore, we aim to assess whether patterns of golden dots on the skin of green …

An Integrative Description Of Euscorpius Diagorasi Sp. N. From Rhodes, Greece (Scorpiones: Euscorpiidae), Konstantinos Kalaentzis, Francesco Frigioni, Eliza Kaitetzidou, Alessio Iannucci, Alexandros Triantafyllidis

Euscorpius

The genus Euscorpius Thorell, 1876 comprises a diverse and taxonomically challenging group of scorpions in the Mediterranean, with Greece representing one of its principal centers of diversity. In this study, we provide an integrative description of Euscorpius diagorasi sp. n., a new species from Rhodes Island, Greece. The new species is described on the basis of adult male and female morphology and mitochondrial COI sequence data. It is a small oligotrichous species characterized by a total length of approximately 21–25 mm, pale yellow to light brown coloration with darker reddish-brown pedipalps, pectinal tooth count of 8 in the male …

Investigation Of Northwest Iowa Pollinator Communities Using Two Survey Methods, Ellary Carson, Mya Cole, Isaac De Young, Sharon Huffman, Naomi Johnson, Genesis Maldonado, Maelee Rodenburg, Travis Sweeney, Tark Griebel, Laurie Furlong, Todd Tracy

Celebration of Research

The ecological services of insect pollinators are well established and the documented decline in pollinator biodiversity is of great concern. Baseline data and continued monitoring are essential as we ongoing trends in pollinator communities and evaluate efforts supporting their recovery. Using two survey methods, our study provides pollinator community data at two conservation sites in Northwest Iowa. In September of 2025, we used three colors of pan traps (blue, yellow, and white) to investigate pollinator communities at a small, reconstructed prairie (Buena Vista County Park) and a nearby partially restored native prairie (The Nature Conservancy Glacial Hills Preserve). We also …

Brown Pelican (Pelecanus Occidentalis) Groundings On A Four-Lane Divided Highway In South Texas: A Comparative Study Using Citizen Science, Bradley Evan Beer, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Integrative Biological & Chemical Sciences Faculty Publications

The population of the once-endangered brown pelican (Pelecanus occidentalis) has increased over the past several decades and is now considered fully recovered. However, in south Texas, the combined effects of weather patterns, transportation infrastructure, and brown pelican biology have led to road mortalities on State Highway 48 (SH 48) at the Carl “Joe” Gayman Bridge. To mitigate these mortalities, the Texas Department of Transportation modified traffic barriers on SH 48. We aimed to examine the effect of the barrier change and determine which weather variables influence brown pelican groundings on SH 48. Citizen scientists monitored sections of SH …