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Unraveling The Behavioral Ecology Of The Western Diamond-Backed Rattlesnake (Crotalus Atrox) Through The Lenses Of Personality, Predator-Prey Interactions, And Crypsis, Oceane Da Cunha

Open Access Theses & Dissertations

To thrive in an environment, individuals need to be able to forage efficiently and acquire mates. These resources are limited, and their acquisition depends upon the energy and time an individual chooses to allocate to each activity and the environmental conditions, leading to behavioral trade-offs. Different species, or even different individuals within the same population, respond to these trade-offs by employing contrasting strategies, leading to differential life-history outcomes. The overarching goal of this dissertation is to gain a better understanding of the trade-offs cryptic ambush mesopredators are facing using the western diamond-backed rattlesnake (Crotalus atrox) as a model species. Each …

Balancing The Scales: Evaluating Variables Of Greatest Impact To Profit Margins When Finishing Cattle, Ryan Bake

All Graduate Reports and Creative Projects, Fall 2023 to Present

This study examines the risk associated with finishing cattle in a feedlot, specifically in the context of historically high cattle prices and quality grade grid marketing systems that have not adjusted to these elevated prices. The analysis also looks at performance factors that drive profitability differences in pens of cattle in a commercial feedlot, and how market factors also impact profitability. Regression analysis determines the significance of performance variables such as days on feed, average daily gain, feed conversion rates, and carcass characteristics on pen profitability. The impact of cattle breeding and pre-feedlot management of the cattle are also considered …

Investigating Associations Between Activity And Performance Traits Across Three Breeds Of Swine Using NuTrack, Dalton R. Obermier

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

Feed costs are the largest contributor towards the variable costs of pork production. To decrease feed cost while not sacrificing output requires an improvement in feed efficiency (FE). A potential approach to expand available phenotypes associated with FE is with activity tracking, yet the relationship between activity and performance is not well defined in swine. Therefore, the objective of this study was to quantify associations between activity and feed intake traits. Average daily feed intake (ADFI) was collected on 1,766 purebred boars of three genetic lines (Duroc, Landrace, and Yorkshire) using FIRE (Osborne Industries, Inc., Osborne, Kansas) at a testing …

Impacts Of Invasive Carp And Their Population Dynamics On Fish Communities In The Missouri River, Joshua F. Kocik

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

Invasive Carp species: Silver Carp Hypophthalmichthys molitrix, Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Black Carp Mylopharyngodon piceus have both potential and realized abilities to negatively impact native species. Specifically, Bighead Carp and Silver Carp as filter feeders have been theorized to be detrimental not only to adult filter-feeding species, but to many fish which rely on plankton and algae in their early-life stages. The impact of Invasive Carp on the overall fish community remains underexplored. The fish communities below Gavins Point Dam (Invasive Carp present) and Fort Randall Dam (Invasive Carp absent) afford the …

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

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

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

The Influence Of Commercial Salmonella Vaccination Programs On Local- And Systemic-Immune Responses And Ceca Microbiome In Egg-Type Chickens, Chrysta Noelle Beck

Graduate Theses and Dissertations

Salmonella vaccination is a widely accepted practice in the United States poultry industry. These vaccines stimulate a strong humoral response to Salmonella serovars and significantly reduce Salmonella load in the bird. In general, a Salmonella vaccination program for an egg-type pullet flock consists of two administrations of a live attenuated Salmonella vaccine at 1- and 6-wk-of-age followed by one administration of a Salmonella bacterin at 12-wk-of-age. Although these vaccines are regarded as effective against paratyphoid Salmonella infections, there are incidences of breakthrough Salmonella infections and severe injection site reactions after bacterin administration. Therefore, the main objective of this dissertation was …

An Analysis Of Fish Assemblages And Flow Regimes Upstream And Downstream Of Falcon Reservoir, Christopher J. Austin

Theses and Dissertations

The lower Rio Grande is regulated by Falcon and Amistad dams. Native fish species rely on the natural flow regime for habitat and spawning. I analyzed streamflow discharge and fish assemblages above and below Falcon Reservoir to assess potential impacts of dam impoundment. Fish collections were conducted by seine, and river discharge data was provided by the International Boundaries and Water Commission. I found significant differences in fish assemblages above vs below Falcon Reservoir, and the flow regime was significantly more altered downstream of Falcon Reservoir. I also identified two Species of Greatest Concern for Texas above Falcon Reservoir (Notropis …

Effects Of Interrupting The Scotophase Period On Bone Health And Performance Of Laying Hens, Alexis J. Clark

All Theses

This thesis aimed to evaluate the effects of interrupting the daily scotophase period on bone health and production in laying hens. Modern commercial laying hens are prone to high rates of bone demineralization due to the constant mobilization of calcium to withstand daily eggshell calcification mechanisms. The industry light standard for laying hens is 16 hours of continuous light (photophase) and 8 hours of continuous darkness (scotophase) daily. During scotophase, physical activity is reduced due to instinctive perching behaviors, and thus, feeding behaviors are halted. However, physiological processes, including digestion, excretion, and reproduction, remain active during scotophase.

Most eggshell formation …

Investigation Of The Pangas (Pangasianodon Hypophthalmus) Cultivation Sustainability In Cages At The Ratargul Freshwater Swamp Forest Of Bangladesh, Mrityunjoy Kunda, Md. Abu Kawsar, Diponkor Adikari, Sakib Tahmid Rishan, Ahmed Harun-Al-Rashid, Debasish Pandit

School of Integrative Biological & Chemical Sciences Faculty Publications

Determining the most appropriate stocking density for a specific fish species in an ambient condition is essential for successful cage aquaculture in terms of profitability which is mainly governed by growth. The current study was conducted to ascertain which stocking density gives the best result of widely cultured species in cage aquaculture, pangas (Pangasianodon hypophthalmus), at swamp forest environment of Ratargul Freshwater Swamp Forest, Bangladesh in terms of growth, production and economic return. Fish were reared for 93 days at three stocking densities, namely 30, 40 and 50 fish/m3 which were denoted as FSD30, FSD40 and FSD50, respectively, …

Local And Systemic Inflammatory And Antibody Responses To Salmonella-Killed Vaccines In Egg-Type Pullets, Jossie Mair Santamaria Archbold

Graduate Theses and Dissertations

Salmonella infection in chickens is a significant and complex challenge to manage, affecting poultry health and food safety. Vaccination against Salmonella is a promising preventative approach to control flock infection and decrease the loads of this pathogen. Vaccination strategies against Salmonella often comprise the application of live attenuated and killed (inactivated) vaccines, including inactivated autogenous vaccines. Live attenuated Salmonella vaccines stimulate both cellular and humoral immunity but can potentially return to a virulent state; meanwhile, inactivated Salmonella vaccines trigger more of a humoral response and are safer since they are entirely rendered inactive. However, there is a lack of information …

Assessment Of American Tannin-Free Grain Sorghum As Feedstuff For Poultry: Nutrient Composition, Amino Acid Digestibility And Bird Performance, Santiago Sasia

All Dissertations

Given the rising cost of poultry diets, alternative ingredients like sorghum are crucial for maximizing returns without compromising product quality. Sorghum's drought tolerance and adaptability, along with its nutritional profile, make it a viable corn substitute. This dissertation examines the nutrient composition, amino acid digestibility, and performance of poultry fed with American tannin-free grain sorghum. Chapter II evaluates the impact of sorghum-based diets, with or without phytase superdosing, on broiler performance, including body weight, weight gain, feed intake, and feed conversion ratio. Results indicate that sorghum can replace corn without adverse effects on broiler performance. Chapter III explores the partial …

Understanding The Role Of The Microbiome In Infectious Disease, Developing Surveillance Tools, And Engineering Direct Fed Microbials To Improve Animal Health, Alison Clare (Bartenslager) Neujahr

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

With the ever-increasing demand for animal protein and the continual need for the assurance of proper animal welfare, investigations of preventative strategies for diseases is greatly needed. Specifically in the cattle industry, infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, causes a large economic loss to the producer. However, effective mitigation strategies are lacking. Partly, this is due to the lack of studies investigating the ocular microbiome. Therefore, studies investigating the bovine ocular microbiome are greatly needed to better understand IBK disease etiology. To this end, we investigated the changes in the ocular microbiome in animals before, during and after …

Phylogenetic And Biogeographic Patterns Of Devonian Proetid Trilobites, Katherine Jane Jordan

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

Ecological disruption events such as mass extinctions can result in the permanent alteration in clades and ecosystems. A pivotal time of change during the history of life on Earth can be seen in the Devonian Period. During this time, major transitions in marine and terrestrial system resulted in a different world at the end of the period in comparison to the beginning. One such group most heavily impacted were trilobites. Trilobites were reduced to one order by the end of the Devonian: Proetida. My dissertation focuses on phylogenetic, biogeographic, and paleocommunity patterns of this group, known as the last of …

The Relationship Between Phosphorus Retention And Fibroblast Growth Factor 23 In Broiler Breeders, A. D. Magnuson, N. Boonsinchai, J. Caldas, J. England, C. Coon

Poultry Science Faculty Publications and Presentations

Previous studies with broiler breeders indicate a P retention threshold when fed daily dietary levels of non-phytate P (NPP) exceeding 320 mg. Fibroblast growth factor 23 (FGF23) is a hormone secreted by osteocytes which modulates P retention and could be the biological agent which controls the P threshold in breeders. To evaluate the relationship between FGF23 and the P retention threshold, a 4 -wk study with 32 -wk -old breeders was conducted with 6 dietary treatments with daily NPP intake of 216 to 576 mg/d/h with increments of 80 mg/kg diet. The goals were 1) to …

California Condor Feeding Habitat, Vigilance, And Competition With Avian Scavengers In Southern Utah, Usa, Alex Blanche

All Graduate Theses and Dissertations, Fall 2023 to Present

Independent foraging is needed for the reintroduction of a species to be successful, but it can cause cascades in interconnected ecological communities. California condors (Gymnogyps californianus) were reintroduced to the Colorado Plateau in 1996, and the population has continued to grow with yearly releases of captive individuals. However, little is known about foraging behavior of condors and their potential competitors. Carrion is a risky food source, and there is a tradeoff between vigilance and feeding. Altering behavior can maximize caloric intake while minimizing risk. Here, I investigate habitat selection, vigilance, and interspecific interactions among condors, golden eagles ( …

Comparative Morphology And Development Of The Trigeminally Innervated Infrared-Imaging System In Boas And Pythons, Helen Bond Plylar

All Graduate Theses and Dissertations, Fall 2023 to Present

Boas and pythons use specialized sense organs called pit organs to detect radiant heat. Pit organs in these lineages occur in paired arrays along the upper and lower jaws and are served by the trigeminal nerve (the fifth cranial nerve and one of the largest). Information from the pit organs travels via branches of the trigeminal to the brain and ultimately is processed in the optic tectum, along with information from the visual system. That means these snakes effectively “see” heat. While studies of the pitviper infrared-imaging system are numerous, very few studies of this system in pythons or boas …

Species Vary In Within-Species Variability, Jennifer Vonk

Animal Sentience

Owens et al. (2024) add to the growing voices stressing the importance of considering individual differences in animal welfare and conservation. I advocate for an additional emphasis on the importance of between species comparisons of the degree of individual variation in cognition and emotion within species. A better understanding of the factors predicting within-species variability will help conservationists target their efforts. Additionally, I caution against invoking circularity in using “behavioural traits” to predict related behaviours.

Twenty-Three Years Of Pcr-Based Seafood Authentication Assay Development: What Have We Learned?, Maleeka Singh, Robert G. Young, Rosalee S. Hellberg, Robert H. Hanner, Maria G. Corradini, Jeffrey M. Garber

Food Science Faculty Articles and Research

Seafood is a prime target for fraudulent activities due to the complexity of its supply chain, high demand, and difficult discrimination among species once morphological characteristics are removed. Instances of seafood fraud are expected to increase due to growing demand. This manuscript reviews the application of DNA-based methods for commercial fish authentication and identification from 2000 to 2023. It explores (1) the most common types of commercial fish used in assay development, (2) the type of method used, (3) the gene region most often targeted, (4) provides a case study of currently published assays or primer-probe pairs used for DNA …

Effects Of Premortem Stress On Protein Expression, Steak Color, Oxidation, And Myofibrillar Fragmentation Index In The Longissimus Lumborum, Reganne K. Briggs, Jerrad F. Legako, Paul R. Broadway, Jeff A. Carroll, Nicole C. Burdick Sanchez, Nikole E. Ineck, Zachary K. Smith, Ranjith Ramanathan, Kara J. Thornton

Animal, Dairy, and Veterinary Science Faculty Publications

No abstract provided.

Estimation Of Effective Number Of Breeders And Effective Population Size In An Abundant And Heavily Exploited Marine Teleost, Andrea Bertram, Justin Bell, Chris Brauer, David Fairclough, Paul Hamer, Jonathan Sandoval-Castillo, Maren Wellenreuther, Luciano B. Beheregaray

Fisheries Research Articles

Obtaining reliable estimates of the effective number of breeders (Nb) and generational effective population size (Ne) for fishery-important species is challenging because they are often iteroparous and highly abundant, which can lead to bias and imprecision. However, recent advances in understanding of these parameters, as well as the development of bias correction methods, have improved the capacity to generate reliable estimates. We utilized samples of both single-cohort young of the year and mixed-age adults from two geographically and genetically isolated stocks of the Australasian snapper (Chrysophrys auratus) to investigate the feasibility of generating reliable Nb and Ne estimates for a …

Road Mitigation Structures Designed For Texas Ocelots: Influence Of Structural Characteristics And Environmental Factors On Non-Target Wildlife Usage, Anna Rivera Roy, Kevin W. Ryer, Md. Saydur Rahman, John H. Young Jr., Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

Roads negatively impact wildlife through habitat fragmentation, loss of habitat connectivity, and wildlife-vehicle collisions, thus road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address this issue all over the world, including in the United States. In South Texas, such structures were built or modified along a State Highway in an effort to address road mortality for the endangered ocelot (Leopardus pardalis) and non-target wildlife species. The goal of this study was to examine temporal changes in wildlife interactions with WCS and WG during and after their construction and …

Populations Of The Stygobiotic Amphipod Palearcticarellus Pusillus (Martynov, 1930) Maintain Genetic Connectivity Between The Mountain Springs And The Deep Bottom Habitats Of Lake Teletskoye (Altai Mountains, Russia), Ivan Marin, Liubov Yanygina, Svetlana Ostroukhova, Dmitry Palatov

International Journal of Speleology

The diversity of underground fauna is often associated with the presence of karst areas, which have extensive underground cavities and connecting channels. Non-karst areas, however, make up a larger portion of the planet’ surface, and our understanding of the distribution and dispersal abilities of underground fauna in these areas currently remains limited. During a recent study of the diversity of stygobiotic crustaceans in the mountain streams of the Kurai Mountain Range (Altai, Russia), a small-sized species of crangonyctid amphipod, Palearcticarellus pusillus (Crustacea, Amphipoda, Crangonyctidae) was found in high-altitude springs. This species has been previously known only from deep-water habitats in …

Conservation Genomic Investigation Of A Threatened Trout Species Endemic To The Gila River, David Thomas Camak

Biology ETDs

Climate change is a looming threat to the persistence of species, especially aquatic, imperiled species. Species native to desert streams are at a particular disadvantage, as many species already face drought, floods, wildfires, and threats from nonnative species, all of which are thought to be exacerbated by climate change. Species such as the threatened Gila Trout (Oncorhynchus gilae) already have small ranges and persist in fragmented and isolated habitats that limits gene flow between populations. Therefore, it is important to understand the current genomic status of such populations to be able to predict the future effects of climate …

Microplastic Accumulation In The Marsh Periwinkle (Littoraria Irrorata), Sarah Keaton, Hannah Lukhard, Eli Windy, Manar Hasan

DePaul Discoveries

Contamination of oceans by microplastics (mm) currently poses a major threat to aquatic and terrestrial ecosystems worldwide. Recent attention towards this issue has raised questions about the extent to which microplastics have accumulated in the environment, and has led to an increase in studies on the effects of microplastics in various organisms. However, levels of contamination in protected natural areas are still largely unexplored, yet can offer an important empirical perspective on the issue. In addition, little is known about the potential effects of microplastics on behavior in the field. This research was conducted within the protected ACE Basin National …

Postweaning Skull Growth In Living Didelphid Marsupials: The Case Of Gracilinanus Agilis And Cryptonanus Chacoensis, Iveth A. Villalobos Guerrero, Noé U. De La Sancha

DePaul Discoveries

Ontogeny is described as the history of an organism through its lifetime including development, growth, and allometry. The ontogenetic approach in cranial dimensions has proved useful in interpreting evolutionary patterns. Among the largest Didelphidae family of Neotropical marsupials, the species of Gracilinanus agilis and Cryptonanus chacoensis are poorly known. In this study, we address three questions; Is there sexual dimorphism in these species? What is the pattern of allometry? Which allometric patterns best describe the patterns in the skull and mandible? We applied geometric morphometrics to describe and test these differences using MorphoJ. A discriminant function analysis was performed to …

Spatial And Temporal Nesting Pattern Of Sea Turtles In Alas Purwo National Park, And Itsimplications For Conservation Management Practices, Nia Kurniawan, Novita Kusuma Wardani, Noviyani Utami, Muhammad Asyraf Rijalullah, Miftah Farid Assiddiqy, Awang Gitayana, Hartono Hartono, Muhammad Fathoni, Andreas Bandang Hardian

Turkish Journal of Zoology

As a sea turtle conservation area, Alas Purwo National Park (APNP) shows different patterns in the four species of turtles thathave nesting records, such as an increase in Olive Ridley Turtle (Lepidochelys olivacea), stability in Green Turtle (Chelonia mydas), anda decline in Hawksbill Turtle (Eretmochelys imbricata) and Leatherback Turtle (Dermochelys coriacea). During the survey, which lastedfrom January to July 2023, we discovered that each type of sea turtle preferred nesting sites at specific hypothetical stations, except forthe L. olivacea, which nested at all hypothetical stations along Pancur-Cungur Coast. We also discovered that it is highly encouragedto continue relocations that have …

Modeling Habitat Suitability And Current Distribution Of The Relicted Maghreb Magpie (Pica Mauritanica), Kamel Eddine Mederbal, Mohcen Menaa, Abdallah Aouadi, Lamia Boutabia, Lamia Bensaâd-Bendjedid, Khalladi Mederbal, Amira Bouderbala, Abderrahmane Chebli, Salah Telailia

Turkish Journal of Zoology

The Maghreb Magpie (Pica mauritanica) is an endemic bird to North Africa, encompassing Algeria, Morocco, and Tunisia. Unfortunately, its population is facing a significant decline primarily attributed to habitat loss and fragmentation resulting from urbanization and agricultural practices. Due to the lack of studies on habitat requirements of Pica mauritanica on a large scale, investigating the habitat preferences of this species and thereby understanding the potential threats, remains crucial for effective conservation strategies. We performed species distribution modeling (SDM), incorporating both occurrence records and predictor variables, to investigate the potentially suitable habitat and the factors influencing the distribution of the …

Limited Thermal Plasticity In High Mountain Tropical Water Bear, Juan Manuel Carvajalino-Fernández, Valentina Diaz-Galvis, Alan Dante Torres-Jaramillo

Turkish Journal of Zoology

Tardigrades, a phylum of microscopic organisms well known for their resistance to extreme conditions thanks to adaptations such as cryptobiosis, in which they are able to suspend their metabolism until more favorable conditions arise. These organisms are found in a wide range of environments, and high Andean mountains are not the exception, even though weather conditions are highly variable during the day, let alone a month. An experiment was thus conducted at 2600m in Bogotá, Colombia to evaluate the resistance of Macrobiotus sp. found on trees, three sets of fifteen tardigrades were exposed to 20 °C, 30 °C and 40 …

Artificial Light At Night On Nesting Beaches Of The Green Turtle, Chelonia Mydas, In The Eastern Mediterranean And Its Possible Effect On Populations, Noam Leader, Yaniv Levy, Oğuz Türkozan

Turkish Journal of Zoology

Artificial light associated with coastal development is becoming one of the major threats to coastal biodiversity. Sea turtles are coastal breeders, and it is well-known that hatchlings tend to move toward lighter objects on the beach, which prevents them from reaching the sea. It is, therefore, essential to identify the impact of artificial light at night (ALAN) on the nesting beaches. Here, we investigated ALAN levels using imagery from satellites at important green turtle (Chelonia mydas) nesting beaches in the Mediterranean. Mean August radiance levels at nesting beaches ranged from 0.00473 nW/cm2sr (Northern Cyprus-South Karpaz Beach) to 14.44 nW/cm2sr (Turkey …

Identification Of Blood Meals In Field Collected Culex Pipiens, Anopheles Sacharovi And Culex Tritaeniorhynchus (Diptera: Culicidae) Using The Elisa Method, Fatma Bursali, Gi̇zem Anti̇ka, Sare İlknur Yavaşoğlu, Fati̇h Mehmet Şi̇mşek

Turkish Journal of Zoology

Information obtained about the blood feeding behavior of mosquito populations in nature is important for understanding their vectorial capacity and evaluating their potential role in the transmission of vector-borne diseases. This study investigated the feeding patterns of Culex pipiens, Anopheles sacharovi and Culex tritaeniorhynchus by using ELISA method. A total of 435 blood-fed females were collected from the Aegean and Mediterranean regions of Türkiye between May 2021-September 2023. The types and numbers of potential domestic animal hosts were recorded in each village. Of the 372 blood meals tested, 348 gave a single host positive result mainly on bovine and human, …