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Exploring Mimicry And Visual Communication In Woodpeckers: A Field Study Utilizing 3d-Printed Models, Lauren M. Smith

Biology Theses

The evolution of similar phenotypes poses an interesting challenge in evolutionary biology. While divergent ecologies may drive differing morphology, physiology, or behavior, similar phenotypes are often due to similar ecology or selection for mimicry. One prominent case of mimetic phenotypes is found in hairy and downy woodpeckers. While several hypotheses might explain the hairy-downy mimicry complex, I aimed to assess the idea that downy woodpeckers benefit from resembling hairy woodpeckers. To test this hypothesis, I used 3D-printed models of various woodpecker species in the field. These models were painted with colors that resemble woodpecker species. The experimental conditions were 3D …

Evaluation Of Fecal Egg Counts (Fec) As A Viable Means To Estimate Ascaridia Galli, Heterakis Gallinarum And Capillaria Obsignata Burdens In Laying Hens, Alexander H. Moss

Animal Science Undergraduate Honors Theses

The control of gastrointestinal helminths, specifically Ascaridia galli, Heterakis gallinarum, and Capillaria obsignata, is a critical component of poultry health management, particularly in free-range and organic farming systems. Methods of estimating parasite burdens, such as post-mortem examinations, are not feasible for large-scale commercial operations due to their invasiveness and time requirements. This study aimed to evaluate the use of fecal egg counts (FEC) as a non-invasive and efficient method for estimating the worm burdens of these parasites in laying hens. A flock of 12 brown egg laying, spent, hens were individually penned on concrete. Fecal samples (both cecal and intestinal) …

Morphology Of Smallmouth Bass (Micropterus Dolomieu) In Arkansas, Robert Laroche

Biological Sciences Undergraduate Honors Theses

The Smallmouth Bass, Micropterus dolomieu, is one of the most important game fishes in Arkansas. Three distinct lineages are recognized from different river basins: the Northern, Neosho, and Ouachita Smallmouth Bass. Understanding the biodiversity within this species complex inhabiting different water bodies in Arkansas is important for effective management of the fisheries resource and to guide conservation efforts. But current data on distribution of distinct forms are insufficient to guide management. The primary goals of the study presented here was to quantify morphological characteristics to identify distinct lineages of Smallmouth Bass, and to determine their specific locations within Arkansas streams …

The Expression Of Intestinal Tight Junction Proteins Induced By 1,25-Dihydroxyvitamin D3-Glycosides Supplementation To Reduce Bacterial Chondronecrosis With Osteomyelitis Lameness In Broilers, Kennedy M. Hicks

Biological Sciences Undergraduate Honors Theses

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a leading cause of lameness in broiler chickens, impacting animal welfare and commercial poultry production. Supplementation using organic trace minerals, vitamin D, probiotics, and prebiotics has been studied to mitigate BCO lameness incidences in broiler chickens. Our previous study demonstrated that feeding Panbonis®-G-1,25(OH)₂D₃ from Solanum glaucophyllum, containing 1 µg/kg G-1,25(OH)₂D₃, to broilers for the first 28 days of their production cycle reduced BCO lameness by approximately 50%. In this study, we investigated the impact of 1,25-dihydroxy vitamin D₃ supplementation on the expression of tight junction …

Evaluating The Economic Viability Of Feeding Hydroponic Barley Fodder To Growing Wethers, Fallon Johnson

All Graduate Reports and Creative Projects, Fall 2023 to Present

As the livestock industry combats challenges including rising feed costs and ensuring sustainable production practices, some attention is being given to hydroponic fodder as a feed source. Hydroponic fodder offers a potential alternative to traditional feed sources. Research has demonstrated hydroponic fodder production has increased water efficiency while providing a sustainable green feed source throughout the year. This study seeks to understand how using hydroponically produced barley fodder in a total mixed ration for growing wethers compares economically to feeding traditional feed sources. A stochastic simulation model is used to determine the expected total feed costs, costs of gain, and …

Ghosts In Glass: Ghost Crabs As Judges Of Glass Sand For Coastal Restoration, Emily Parrish

Honors Theses

Over 60% of the Gulf of Mexico coastline is actively eroding, which has resulted in thousands of miles of lost coastline over the last 100 years. This drastic loss of coastal land highlights the dire need for coastal restoration across the entirety of the Gulf Coast. A vital aspect of restoring these eroded areas is replenishing eroded substrate, traditionally conducted through offshore dredging of substrates which comes with high economic and ecological costs. Recycled glass sand may be able to fill this role and reduce our reliance on dredging while lowering the amount of glass waste entering landfills each year. …

Impacts Of Toxic Fescue Seed Consumed By Pregnant Heifers On Maternal Blood Flow And Offspring Growth Parameters: Potential For Melatonin As A Therapeutic To Improve Offspring Growth, Rachel Scott

Graduate Theses and Dissertations

The southeastern United States is home to endophyte-infected (E+), toxic, tall fescue grass. Consumption of E+ fescue by livestock has been linked to fescue toxicosis, a disease reported to cost the United States beef industry around $1 billion in annual losses. The primary objective of this dissertation was to evaluate the influence of pregnant cattle consuming E+ seed during gestation on uterine artery blood flow and growth performance of female offspring. The secondary objective was to investigate melatonin supplementation as a mitigation strategy for expected fescue-associated decreases in uterine artery blood flow and offspring growth performance. The study reported in …

Sibship Analysis Of Fall And Spring Spawn Gulf Sturgeon Eggs In The Choctawhatchee River, Florida, Lyric Mccullouch

Honors Theses

The Gulf sturgeon (Acipenser oxyrinchus desotoi) is an anadromous species that inhabits rivers along the northern Gulf of Mexico. Facing challenges from overfishing and habitat alteration, the Gulf sturgeon is listed as threatened under the Endangered Species Act. This study investigated the genetic distinctiveness of fall and spring spawning groups of Gulf sturgeon in the Choctawhatchee River, a critical habitat for the species. In this study, I used microsatellite loci to analyze Gulf sturgeon eggs previously collected in the fall and spring of 2019 and 2020. The goals of this study were to verify the genetic identity of …

Ghrelin And Decision-Making: Exploring Its Role In Food Reward, Novelty-Seeking, And Cost Valuation, Serina A. Batson

Open Access Theses & Dissertations

When low energy levels are detected, Ghrelin, a peptide hormone, is produced in the fundus of the stomach. Referred to as the "hunger hormone", Ghrelin is traditionally associated with increased food intake and blood sugar levels. A key modulator in the gut-brain interaction, Ghrelin's growth hormone secretagogue receptor can be found widely across the cortico-striosomal circuit. Critical for decision-making, Ghrelin-based manipulation of this circuit can directly affect reward and cost valuation. While Ghrelin is uniformly considered to increase the valuation of food-based rewards, little research has explored its impact on non-food-based rewards or its effects on cost valuation. Therefore, to …

Walleye And Sauger Movement And Entrainment In Lewis And Clark Lake, William Joseph Radigan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Walleye Sander vitreus and Sauger Sander canadensis are both socioeconomically important sportfish species in Lewis and Clark Lake, an interjurisdictionally managed mainstem Missouri River reservoir fishery. Since 2011, adult catch per unit effort (CPUE) of both Walleye and Sauger has remained at approximately 50% of pre-2011 levels. A presumed reason for the suppressed CPUE of adult Walleye and Sauger is substantial entrainment of larval and adult fish resulting from the reservoir’s high turnover rate (7.2 d). Acoustic telemetry was used to quantify adult movement and entrainment and ichthyoplankton trawls were used to assess larval entrainment. Relative importance of factors driving …

Heterotopias Of Confinement: Zoo Architecture And The Loss Of Elephant Agency, Clayton Gill Beasley

Electronic Theses and Dissertations

Zoos functions as a site where human-animal relationships are structured through built environments that mediate control and representation. This study examines zoos as heterotopias—spaces where power and surveillance are negotiated between human observers and captive nonhuman animals. While zoos are often framed as spaces of conservation and education, their architectural design reinforces hierarchies of observation and confinement, shaping both human perceptions of nature and the lived experiences of nonhuman animals. This research focuses on Asian elephants as a critical species within this framework, exploring how their captivity illuminates tensions between human-imposed structures and nonhuman autonomy. Drawing from theories of heterotopia, …

Epidemiological Inferences Of The Impacts Of Winter Ticks On Moose Health, Krishna S. Woerheide

Department of Entomology: Dissertations, Theses, and Student Research

The North American Moose (mooz in Anishinaabemowin, Ojibwe language, Alces alces), a culturally significant subsistence species for the Anishinaabe people, faces population decline due to calf predation, pathogen transmission, and parasitism by the winter tick (Dermacentor albipictus), all exacerbated by climate change. This study explores the impact of winter tick infestations on moose health, with a focus on natural mineral seeps as potential transmission hotspots in moose habitats within the Grand Portage Indian Reservation (Gichi Onigaming), on Isle Royale National Park (Minong), and within the 1854 Ceded Territory (greater northeastern Minnesota) - ancestral and present homelands of …

Ediacaran Paleocommunity Structure, Body Size Evolution, And The Rise Of Complex Animals, Matthew Philip Craffey

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Ediacaran period (635-538ma) is a key interval in the evolution of life as it records the first macroscopic animal communities. Major extinction pulses appear to have altered the composition of the global marine biosphere between each sub-interval of the Ediacaran Period: the Avalon, White Sea, and Nama assemblage Zones. While considerable attention has been paid to the causes of these extinction pulses, less has been afforded to the consequences of Ediacaran biotic turnover for community organization and function. Moreover, it is unclear how body size - the defining trait of macrofauna - affected the transition between animal groups across …

Spatial Ecology And Predator–Prey Interactions Of Mountain Lions In California's San Francisco North Bay, Jacob A. Harvey

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

Understanding spatial ecology and predator-prey interactions are central to wildlife ecology and conservation. We tracked mountain lions with GPS telemetry to evaluate space use, predator-prey interactions, and resource selection in California’s San Francisco North Bay, USA. In Chapter 1, we evaluated the influence of human disturbance on home range size, prey composition, and kill rates on black-tailed deer (Odocoileus hemionus columbianus) across an urban-rural gradient. Both males and females increased home range size with increasing development at low to moderate levels of development, but female home range size stabilized across greater proportions of development while male home range …

Assessment Of Sampling Gears For Bigheaded Carp In Mid-Order Prairie Rivers In Nebraska, Brett M. Anderson

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

Silver Carp Hypophthalmichthys molitrix and Bighead Carp H. nobilis (collectively bigheaded carp) have invaded tributaries to the Missouri River and Platte River in Nebraska, USA. Information pertaining to efficient sampling protocols for assessing bigheaded carp populations as well as benefiting removal efforts is needed. Herding is a method used to increase the capture efficiency and detection probability of adult bigheaded carp by simultaneously using active and passive sampling gears. During June-July 2023, four herding techniques were assessed regarding their ability to elicit directional movement past an enclosure gate. The combination of sound and electrofishing resulted in the highest mean …

Creating A Stat2 Knock-Out Rat With Crispr/Cas9 Using I-Gonad, Isabella Dejesus

Undergraduate Honors Capstone Projects

Through the use of genetically modified animals, a more holistic understanding of physiologic responses to various diseases and pathologies can be obtained^7,19. The STAT2 gene encodes a protein called Signal Transducer and Activator of Transcription 2 and is an excellent target for genetic manipulation due to its essential role in type I and III interferon signaling pathways¹¹. A member of the STAT family of transcription factors, this protein is directly involved in mediating cellular responses to various cytokines and growth factors, particularly those related to the innate immune response¹¹. While the STAT2 signaling pathway …

A Comparative Study Of Urban And Natural Nesting Gray Hawks In The Lower Rio Grande Valley Of South Texas, Evan Farese

Theses and Dissertations

Urbanization can negatively impact birds of prey, which occupy higher trophic levels. The Gray Hawk (Buteo plagiatus) is a neotropical raptor inhabiting the Lower Rio Grande Valley (LRGV) of Texas, where it is threatened. The species’ ecology has been little studied and it is unclear how urbanization may affect population viability. I studied Gray Hawk reproductive success, diet, and thermal ecology at nests in urban and natural habitats in the LRGV. Camera trap data showed adults at urban nests delivered mostly avian prey, while mammalian prey was most frequently brought to natural nests. Data from temperature loggers showed …

First Specimen-Based Record Of Barbonymus Schwanefeldii (Bleeker, 1854) (Teleostei: Cyprinidae) From Laguna De Bay, Philippines, Kent Elson S. Sorgon, Marjorie Juliana L. Martinez, Andrei Justin F. So, Mariko Franccesca R. Aboganda, Jazreen Nicole G. Parungo, Aeris Johanne G. Poricallan, Keona Tiffany B. Prieto, Mellissa Jewel S. Magday, Alexa Charlize Dc Geronimo, Ma. Vianca Julia E. Anupol, Derreck O. De Leon

Biology Faculty Publications

The introduction of non-native fish species in the freshwater ecosystems of the Philippines presents a clear threat to native ichthyofauna, making verified reports of such introductions all the more critical. Through the examination of a collected specimen and anecdotes from fisherfolk and social media, we present here the first records of the occurrence of the tinfoil barb, Barbonymus schwanefeldii (Bleeker, 1854), in Laguna de Bay, Luzon Island, Philippines. This represents the addition of another non-native fish species in this lake, which is increasingly becoming dominated by non-native and invasive fishes that have been intentionally or accidentally introduced. Monitoring landed fish …

Mechanisms Of Behavioral Change In Hosts Of Toxoplasma Gondii: A Review, Olivia Grimsley

Senior Honors Theses

The parasite Toxoplasma gondii is a highly ubiquitous parasite that latently infects an estimated 33% percent of the global population. Toxoplasmosis is of obvious clinical significance due to the extremely high risks to the unborn who contract it congenitally. Less attention has been given to a more subtle aspect of latent infection, which is the behavioral alterations that are commonly experienced by those who contract the parasite. Infected individuals commonly display a variety of altered behaviors, such as increased aggression and risk-seeking behaviors, depression, higher tendency towards suicide and self-directed violence, a loss of fear response, and a greatly increased …

Establishing Methods For In Vitro Static Culture Of Gut Microbiomes For Nutritional Intervention Studies, Jeremy Mathew Case

Undergraduate Honors Capstone Projects

Lipid oxidation products (LOPs), which form during high-heat processing of oils common in Western diets, are known to cause inflammation and cellular damage. While LOPs have been implicated in exacerbating colitis and promoting colon tumorigenesis in mouse models, their direct impact on the gut microbiome remains poorly understood. This capstone project aimed to develop a low-cost in vitro protocol to culture the mouse gut microbiome under anaerobic conditions, enabling future investigations into the direct effects of bioactive dietary compounds such as LOPs. The study also assessed whether viable microbial communities could be recovered from fecal samples stored at -80°C. Fecal …

A System And Method For Measuring Spatially Varying Surface Appearances With A Study Of Feathers, Jessica Baron-Lis

All Dissertations

Real-world materials, particularly biological structures such as feathers exhibit complex appearances that vary spatially across their surfaces. The field of computer graphics provides a means of understanding such surfaces through material modeling which uses both analytical models and data acquired from light-surface interactions. There are many efforts within the past decade in measuring materials for graphics, but common limitations in these works include not accounting for spatially varying properties and reliance on neural networks and synthetic datasets.

Feathers from modern birds present diverse appearances due to how light interacts with their unique hierarchical microstructures. Variations in those structures lead to …

Greater Sage-Grouse Habitat Dynamics And Grazing, A Study Of Vegetation Indices And Survival, Codi R. Backen

All Graduate Theses and Dissertations, Fall 2023 to Present

North American rangelands are vast, open landscapes that support diverse ecosystems and provide many ecosystem services. Many wildlife call sagebrush rangelands home, including the Greater sage-grouse (sage-grouse; Centrocercus urophasianus). Sage-grouse habitat encompasses 165 million acres across western North America, and this bird has been of conservation concern as their populations drastically declined since the 1960s. Rangelands are also grazed by livestock, which has the potential to negatively affect sagebrush ecosystems when overgrazed or overstocked, which could be detrimental to sage-grouse nesting habitat. Additionally, sagebrush rangelands undergo annual variations in precipitation, temperature, growing season length, and vegetation vigor, which has …

Stereotypic Behaviors And Physiological Indicators Of Stress Occur In Horses With Restricted Durations Of Turnout, Elizabeth E. Rodgers

Department of Animal Science: Dissertations, Theses, and Student Research

The confinement of horses to stalls with limited or no turnout time restricts their natural roaming behaviors, which potentially increases stress and behavioral stereotypies. This study investigated the impact of turnout duration on behavioral and physiological stress indicators in healthy horses. Adult horses (n = 11) were enrolled in a 3 treatment (0-, 15-, and 60-minute turnout/day) Latin square design, including 3 12 d experimental periods over 6 weeks. Horses were acclimated to turnout (24.38 x 64.01m indoor arena) and stalls (2.74 x 4.87m - 3.66 x 3.66m) stalls prior to data collection on day 1. Experienced handlers managed …

Digestibility, Palatability, And Nutrient Composition Of Three Species Of Whole Prey In Three Species Of Snakes, Morgan R. Kienzle

Department of Animal Science: Dissertations, Theses, and Student Research

Snakes in human care often lack diversity in the diet. Rodents account for the majority of meals, while wild snakes are consuming a varied diet composed of multiple different whole prey species. By feeding only one species of prey, the chance of nutrient deficiencies and other health concerns increases. To promote variety in the managed diet, two commercially available whole prey species (mice (Mus musculus) and chicks (Gallus spp.)) and one novel species (Seba’s short-tailed bats (Carollia perspicillata)), were analyzed for their dry matter (DM), organic matter (OM), crude protein (CP), crude fat …

Methane Mitigation And Its Effects On Energy Utilization In Lactating Dairy Cattle, Shan C. Sherwood

Department of Animal Science: Dissertations, Theses, and Student Research

Improved methane (CH₄) mitigation strategies are needed to achieve the greenhouse gas emission goals of the dairy industry. The first experiment was conducted to evaluate the effects of feeding black cumin (Nigella sativa) seed oil and acetate (BCA) on CH₄ production and whole-animal energy utilization. Twelve dry Jersey cows were used in a 2-period crossover design study with 28d periods. The BCA treatment was compared to a control diet with corn oil. Both BCA and corn oil were added to the base diet as a top dress. Results from this study did not show any …

Precision Feeding Methods To Increase Nitrogen And Energy Utilization In Lactating Dairy Cows, Chloe Emily Moss Harris

Department of Animal Science: Dissertations, Theses, and Student Research

The environmental and economic costs of overfeeding N to dairy cattle are a challenge in today’s dairy industry. Two studies were conducted to address new opportunities for precision feeding N, which is a strategy where producers strive to feed cows the precise amount of N and amino acids that meet their individual requirements.

The objective of the first study was to evaluate the effects of supplementing a rumen protected methionine (RPM) product via automatic milking system (AMS) concentrate on milk protein yield in lactating dairy cows. Fifty-one cows were randomly assigned to control (no RPM) or treatment groups. Milk yield …

Gonadotropin-Releasing Hormone Ii And Its Receptor: Novel Regulators Of Semen Quality And Follicular Function In Swine, Caitlin Elizabeth Ross

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Pigs are the only mammalian livestock species encoding functional proteins for the second form of gonadotropin-releasing hormone (GnRH-II) and its receptor (GnRHR-II). In the first study, GnRHR-II localized to developing germ cells and the connecting piece of ejaculated spermatozoa. Concurrently, GnRH-II was most abundantly produced in the testis compared with other reproductive tract organs and was present within seminal plasma. Moreover, treatment of extended semen with GnRHR-II analogues altered sperm motility, morphology, and kinematics. For remaining studies, we utilized a swine line with ubiquitous knockdown of GnRHR-II (GnRHR-II KD) developed in our laboratory. The second study demonstrated that circulating GnRH-II …

Distribution Of Mussels In Two Intermittent Upland Streams Of The Arkansas Valley Ecoregion, Aaron A. Brady, Seth Drake, Zach Crain, Kendall Moles

ATU Scholars Symposium

Freshwater mussels are facing an increasing need for conservation due to their declining populations. More data is needed on mussel distributions, especially in tributaries of large rivers to properly conserve and restore populations. Big Shoal Creek and Little Shoal Creek are two upland-tributaries of the Arkansas River (Lake Dardanelle) in which no records exist for freshwater mussel populations. We addressed this knowledge gap by sampling a total of 9 sites in Little Shoal Creek and 18 sites in Big Shoal Creek to determine the abundance and distribution of mussels in these streams. Mussels were sampled using a timed search approach. …

Using Guano To Determine Ozark Big-Eared Bat Cave Occupancy In Arkansas​, Lark E. Sybrant

ATU Scholars Symposium

The Ozark big-eared bat (Corynorhinus townsendii ingens) is endangered in Arkansas and is known to have small populations, range restrictions, and specific habitat requirements in the Ozark-St. Francis National Forest. Beyond their known range, there are other potentially suitable areas that have not been confirmed. We aim to test whether the non-invasive genetic analysis of guano samples can identify Ozark big-eared bat cave use and expand their known range. Additional locations need to be surveyed to ensure site protection, as unknown caves are susceptible to human disturbance and damage. Twenty-five sites were surveyed at the southeastern extent of their known …

Comparing Parasitism And Resistance To Flow In Two Populations Of Elimia Virginica, Morgan G. Hicok, Abbie Tomba, Kate Green

Departmental Honors & Graduate Capstone Projects

Snails are important in freshwater ecosystems as primary consumers and are good indicators of the stability of a habitat. Trematodes are parasitic flatworms that infect freshwater snails and can cause changes in metabolic function and growth. Flow rates and water levels are now more variable due to climate change, increasing stress and dislodgment in the snail population. This study investigates how parasites, shell morphology, and native flow environment influence resistance to disturbance. Elimia populations were sampled for differences in parasitism, shell morphology, and ability to withstand high flow environments in two different rivers. Sample sites at the Potomac River were …