Digital Commons Network^™

Invasive Coqui Frogs Serve As Novel Prey For Birds In Hawaii, And Not As Competitors, Robyn L. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Puerto Rican coqui frog was introduced the Hawaiian Islands in the late 1980s. Because of the frog's loud call and high abundance, the State of Hawaii has spent millions of dollars on its eradication. Conservationists are also concerned that the frog could negatively impact Hawaii's endemic birds, which are already threatened by a host of other invasive species, either by competing with them for insects or by increasing bird predators. The purpose of this research was to investigate the impacts of coquis on Hawaiian birds. First, we examined overlap in prey resources between coquis and birds, and second, we …

Spatial Ecology And Captive Behavior Of Rehabilitated Black Bears In Utah, Patrick J. Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animal movements and space use are fundamental components of life and play integral roles in organismal fitness, population dynamics, and the ecology and evolution of species. The heterogeneous distribution of resources and the movement required to access them, results in ecology being a fundamentally spatial concept. Thus, elucidating animal-habitat relationships is a central focus of wildlife ecology and conservation. I utilized GPS technology, resource selection functions, and generalized linear mixed models, to investigate the immediate post-release movements, denning chronology, release-site fidelity, and season-delineated movements, home ranges, and resource use for six, orphaned and rehabilitated black bears (Ursus americanus). …

Migratory Waterbird Ecology At A Critical Staging Area, Great Salt Lake, Utah, Maureen G. Frank

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Millions of birds use Great Salt Lake, Utah, during their migrations every year. While many of the birds use the shorelines and wetlands around Great Salt Lake, there are three migratory species that use the open waters of Great Salt Lake: Wilson's phalaropes (Phalaropus tricolor), red-necked phalaropes (Phalaropus lobatus), and eared grebes (Podiceps nigricollis). Eared grebes feed primarily on brine shrimp (Artemia fanciscana), while phalaropes are thought to consume brine flies (Ephydridae) and brackish-water aquatic invertebrates. Despite the reliance of phalaropes and eared grebes on the invertebrate prey of Great Salt Lake, …

Effects Of Feeding High-Moisture Corn Grain With Slow-Release Urea In Dairy Diets On Lactational Performance, Energy And Nitrogen Utilization, And Ruminal Fermentation Profiles By Lactating Cows, Braden M. Tye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this experiment was to determine if nutrient utilization and energy partitioning by lactating dairy cows would differ in response to dietary corn grain (CG) types [steam-flaked corn (SFC) vs. high-moisture corn (HMC)] and to test if the types of CG would interact with slow-release urea (SRU) on lactational performance and energy utilization. Eight multiparous Holstein cows (32 ± 8.2 days-in-milk) were used in a duplicated 4 × 4 Latin square with one square consisting of ruminally cannulated cows. A 2 × 2 factorial arrangement was used to test 4 dietary treatments: SFC without SRU, SFC with SRU, …

An Analysis Of The Feasibility Of Anaerobic Digestion On Small-Scale Dairies In Utah, Steven Chans Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With an ever increasing concern for the environment, different methods of managing organic waste on dairy farms have been explored and analyzed. Anaerobic digestion has long been a popular method of managing organic waste. Its popularity stems from the potential to decrease greenhouse gases, improve air quality and provide a source of additional revenue for the farm. Problems with implementing anaerobic digestion arise from high failure rates, high start-up costs and continuous maintenance and equipment replacement.

Subsidies for the initial investment and improved technology have increased the possibility of large-scale dairy farms to adopt anaerobic digestion. Due to economies of …

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Entrepreneurs' Perceived Factors Of Success And Barriers-To-Entry For Small Business And Farm Operations In Rural Paraguay, Braden J. Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Both agriculture and nonagriculture activities are important for Paraguay's economy and its rural development plan. Ensuring opportunity for successful enterprise creation and expansion will facilitate new business entrance, while also growing rural economies. Past research has identified many factors that contribute highly to business and farm operation success, though little information exists about the perceptions of would-be entrepreneurs.

This study analyzes perceptions and characteristics of young, would-be entrepreneurs and agriculture producers in rural Paraguay to better understand their views of business/farm success and hurdle factors. Results suggest that increased experience, education and business exposure will decrease perceptions of many barrier …

Influence Of Disturbance On Greater Sage-Grouse Habitat Selection In Southern Utah, Erica P. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern that occupies sagebrush-dominated (Artemisia spp.) landscapes across the western United States and southern Canada. The U. S. Fish and Wildlife Service (USFWS) reviewed the status of the sage-grouse in September 2015 and determined that it did not warrant protection under the Endangered Species Act due to collaborative efforts between numerous public and private stakeholders. However, this decision hinged on federal and state commitments to continue science-based management of sagebrush habitats. As human development increases across the west, there is an increasing need for understanding …

Establishment And Trends In Persistence Of Selected Perennial Cool-Season Grasses, Craig W. Rigby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The choice of plant materials is an important factor in restoration or revegetation of disturbed rangelands. To better identify plant materials that could be adapted to increased competition from invasive grasses and fluctuations in temperature and precipitation, there is a need to understand potential seedling establishment, plant persistence, and dry-matter yield (DMY) as a measure of plant vigor in the newly developed varieties across a wide range of environmental conditions. Experiments were conducted on four semiarid range sites to compare these traits in 14 perennial cool-season grass species currently used for revegetation in the Western U.S.A. There were location differences, …

Examining The Utah 4-H Volunteer Program: The Effects Of Donation And Motives In Relation To Volunteer Recruitment And Retention, Kelsey W. Romney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah 4-H is a volunteer driven, youth development program. The success of Utah 4-H depends on the recruitment and retention of volunteers. The purpose of this study was to identify recruitment and retention motivators and how those motivators related to the unique cultural demographics of Utah 4-H volunteers. Results show that volunteers did not begin volunteering because of their religious affiliation; however, those who were religious were more likely to remain active volunteers for Utah 4-H. The underlying motive of 4-H volunteers, related to all types of involvement in the program, was an altruistic desire to help others.

Does Experience With Sagebrush In Utero And Early In Life Influence The Use Of Sagebrush By Sheep?, Ashley T. Longmore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Learning from mother begins early in the developmental process and can have lifelong effects when it comes to forage preferences. Recent research suggests that mothers are a powerful and positive influence before birth. Pregnancy is not an incubation period buy a staging period for well-being and disease later in life. Better understanding the developmental processes which take place in utero and the effects they have later in life may help us create management plans that utilize grazing animals to their full potential as landscape manipulators.

Using in utero and early-life programming as a management tool is a relatively new concept, …

An Allometric Approach To Evaluate Physiological And Production Efficiencies In Tree Size For Tart Cherry And Apple Orchard Systems, Zachary T. Brym

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In orchard systems, the size of a tree and the physical structure of its canopy influences how the tree gathers resources and uses them to produce fruit. Smaller orchard trees produce a higher proportion of fruit relative to their size. Small trees also produce higher quality fruit than larger trees. These relationships were demonstrated for apples and tart cherries grown in Utah. In physiological ecology, models called allometries have been developed that explain how the size of wild plants is related to growth, architecture, and reproduction. These models were applied to apple and tart cherry orchard systems and revealed consistent …

Control Of Large Stands Of Phragmites Australis In Great Salt Lake, Utah Wetlands, Chad R. Cranney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites (common reed) is a non-native, invasive perennial grass from Eurasia that is taking over wetlands across North America. In Utah, Phragmites has expanded to cover tens of thousands of acres in and around the Great Salt Lake (GSL). The GSL and its associated wetlands are recognized regionally and hemispherically as an important bird area (IBA) that provide critical habitat for a wide variety of wetland dependent birds. The invasion and expansion of Phragmites has replaced many of the high quality habitats these avian populations rely on. This research aimed to determine the most effective methods to control Phragmites and …

Balancing Agricultural And Urban Water Needs In Transitioning Arid Landscapes, Bonnie Roos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the arid western United States (U.S.), population expansion is dependent on water supply. With the majority of the water being consumed in agriculture, municipalities often obtain water supply needed for growth from agriculture. This exchange occurs through agricultural-to-urban water right transfers. This trend drives the question of how to strike a balance between agricultural and urban water needs in rapidly growing arid regions.

Utah, located in the Intermountain region of the western U.S., is a state with a rapidly growing population and limited water supply. This research focuses on existing challenges and opportunities for balancing expanding municipal development and …

Relationships Between Riparian Vegetation, Hydrology, Climate And Disturbance Across The Western United States, Nathaniel Hough-Snee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flow regime, the magnitude, duration and timing of streamflow, controls the development of floodplain landforms on which riparian vegetation communities assemble. Streamflow scours and deposits sediment, structures floodplain soil moisture dynamics, and transports propagules. Flow regime interacts with environmental gradients like climate, land-use, and biomass-removing disturbance to shape riparian plant distributions across landscapes. These gradients select for groups of riparian plant species with traits that allow them to establish, grow, and reproduce on floodplains – riparian vegetation guilds. Here I ask, what governs the distributions of groups of similar riparian plant species across landscapes? To answer this question, I identify …

Spider Aggregate Glue Sequence Characterization And Expression, Kyle Berg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Orb-weaving spiders create a glue which is secreted onto the web to capture and retain insects. This glue is made from aggregate protein. Aggregate glue is sticky when wet and can stretch far when pulled at slow speeds, and pull back with a greater force if pulled at high speeds which helps it achieve its purpose as the adhesive that keeps insects in the web. These features also make it an attractive target for applications such as a surgical glue or underwater adhesive. Unfortunately, very little is known about the aggregate glue gene, and knowledge of the genetic sequence is …

Increasing The Sustainability Of Utah Farms By Incorporating Quinoa As A Novel Crop And Protecting Soil Health, Kristine R. Buckland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most of the western United States faces increasing water shortages in the coming years, that will present a major challenge for maintaining sustainable farms. Incorporating an alternative crop that is well adapted to projected changes in climate could be a successful approach to increasing the sustainability of farms in the region. Quinoa, Chenopodium quinoa Willd., may be an ideal alternative crop to meet the demands of the Intermountain West. Before widespread adoption of this novel crop can occur, best management strategies need to be documented. This paper provides research on cropping systems, irrigation rates, and weed competition with quinoa. Additionally, …

Agricultural Nitrogen Management Affects Microbial Communities, Enzyme Activities, And Functional Genes For Nitrification And Nitrogen Mineralization, Yang Ouyang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Improved understanding of nitrogen cycling in agriculture is essential for increasing fertilizer use efficiency and sustainable food production. The availability and mobility of nitrogen are largely determined by the processes of nitrogen mineralization and nitrification. Nitrification is mediated by ammonia oxidizing bacteria, ammonia oxidizing archaea, and nitrite oxidizing bacteria. Our understanding of the controls on the relative activity of these nitrifying organisms in soil is limited. A wide variety of soil microorganisms produce enzymes that mineralize nitrogen from organic matter, but we have limited knowledge about links between enzyme activity and the microbes that work in soil. The main objective …

Crystallization Behavior Of Waxes, Sarbojeet Jana

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Partially hydrogenated oil (PHO) has no longer GRAS status. However, PHO is one of the important ingredients in bakery and confectionary industry and therefore the food industry is seeking for an alternative fat to replace PHO. Waxes have shown promise to fulfill that demand because of its easy availability and cheap in price. Waxes with high melting points (> 40 °C) help in the crystallization process when mixed with low melting point oils. A crystalline network is formed in this wax/oil crystallization process where liquid oil is entrapped in wax crystal network. A new material is formed which is neither …

Hybridization, Population Genetic Structure And Gene Expression In The Genus Boechera, Martin Peter Schilling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When we look at life on earth, we can see a lot of different life forms, but we still do not fully understand how these different life forms came to be and at which points in time these life forms began to be different enough from each other so we could call them by different names, or species. Some groups of species on earth, especially plants, seem to reproduce with each other, even though they are already very different from each other so that we call them different species. This process is called hybridization, and it can stir up the …

Douglas-Fir Beetle Mediated Changes To Fuel Complexes, Foliar Moisture Content And Terpenes In Interior Douglas-Fir Forests Of The Central Rocky Mountains, Andrew D. Giunta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bark beetle outbreaks have affected millions of hectares of forests across western North America and are a major concern for forest managers. Aside from causing extensive tree mortality, other associated changes include alterations to forest structure in terms of modifications of surface and aerial fuels, which have led to concerns about overall forest health and wildfire risk. The majority of research into the interactions between bark beetles, fuels, and wildfire, has focused on upper elevation forests primarily in lodgepole pine and Engelmann spruce. Little research has been led in lower to middle montane forests which typically are more structurally and …

Structural And Biochemical Characterization Of The Frequency-Interacting Rna Helicase Frh, Jacqueline M. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cells function through a variety of regulatory pathways intricately communicating with one another. These pathways ensure that cellular functions happen at the appropriate times and keep the natural balance within the cell. When pathways do not communicate appropriately, this can lead to disease states and cell death. Two such connected pathways in Neurospora crassa involve the regulation of RNA levels and the circadian rhythms essential for these cells to maintain homeostasis. These pathways are connected by a unique helicase called the Frequency-interacting RNA Helicase (FRH), named for its discovery with the frequency protein involved in the circadian oscillation of the …

Comparing Conventional And Noninvasive Monitoring Techniques For Assessing Cougar Population Size In The Southern Greater Yellowstone Ecosystem, Peter D. Alexander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the abundance or density of wildlife populations is needed for informed decision-making by wildlife biologists. Cougars (Puma concolor), however, are a highly secretive species occurring at very low densities across the landscape, and thus their populations are difficult for biologists to accurately assess. The conventional, and most trusted, method entails physically trapping and radio-collaring as many cougars as possible in a population, and then performing a simple count to determine a minimum population size. While accurate, this method is prohibitively expensive, logistically challenging, and behaviorally disruptive to the study animal. Many noninvasive surveying techniques, such as camera …

Effects Of Thermosonication On Microbial Population Reduction And Solubility Index In Skim Milk Powder, Nicola F. Beatty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermosonication has been researched as a means to improve shelf life, quality, and functional properties in dairy products. This study explored the effects of thermosonication on the inactivation of Geobacillus stearothermophilus in concentrated skim milk as a function of total solids content, temperature, and time and investigated changes in the solubility of the skim milk. Results showed thermosonication had an increased bactericidal effect on both vegetative cells and spores as compared to heat treatment alone without affecting solubility. A model was developed using response surface analysis showing that log reductions produced by thermosonication can be predicted based on a polynomial …

The Demography And Determinants Of Population Growth In Utah Moose (Alces Alces Shirasi), Joel S. Ruprecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Moose (Alces alces) occur widely in northern regions of the world. Across their distribution, the species is considered to be of high intrinsic, ecological and recreational value. Populations of moose along their southern range limit in North America have shown erratic population dynamics in recent decades including severe numeric declines in some areas. Moose in Utah belong to the Shiras subspecies, which is a relatively understudied population segment. Additionally, moose in Utah represent the southernmost naturally occurring moose populations worldwide. Concerns over possible declines and a paucity of baseline data on moose within the state prompted the Utah …

Effect Of Chronic Administration Of Oxytocin On Corpus Luteum Function In Cycling Mares, Katherine Clissold Parkinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Undesirable and variable behavior in mares related to the reproductive cycle is a common issue reported in the equine industry, especially for female horses in a performance setting. These behaviors can interfere with and decrease, overall performance. The objective of this study was to determine if administration of 60 units of the hormone oxytocin once daily for 29 days, regardless of when treatment was initiated during the estrous cycle, would induce prolonged corpus luteum function in cycling mares. Mares were randomly assigned to two groups: 1) saline-treated control (n=7) and 2) oxytocin-treated (n=9). Control mares received 3 cc saline and …

Refining Methods For Quantifying Macroinvertebrate Estimates Of Preference For Use In Stream Bioassessments, Ellen F. Wakeley Tomlinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two-thirds of United States stream length is in either fair or poor biological condition. However, we do not yet have reliable, quantitative tools to diagnose site-specific causes of biological impairment. One way to diagnose causes of impairment is to compare the environmental tolerances or preferences of the taxa expected at a site to those of the observed community. Stream ecologists have derived tolerance values (TVs) from field data for use in causal analysis, but inconsistencies across studies cast doubt on the accuracy of these TVs. Published TVs may not agree with one another for several reasons, including: differences in the …

The Effects Of Hazing On Urban Coyotes, Dakota Reed

Undergraduate Honors Capstone Projects

Urban expansion has rapidly increased over the last few decades. Over half of the human population now lives in urban areas (United Nations 2014). This has resulted in many carnivores being forced to adapt and find ways to use urban resources to survive (Bateman and Fleming 2012). While larger carnivores usually end up locally extinct, some medium sized predators like red fox (Vulpes vulpes), coyotes (Canis latrans), and raccoons (Procyon lotor) thrive in urban environments (Bateman and Fleming 2012). Having these carnivores living among humans can have both positive and negative consequences for the …

Relationships Of Beef Cattle Temperament With Feedlot Performance, Jeffrey James Briscoe

Undergraduate Honors Capstone Projects

This study determined relationships between beef cattle temperament and their feedlot performance. Thirty-five Angus cross-bred steers and heifers (18 steers and 17 heifers) were placed in the Utah State University feedlot to take part in the feed trial. Cattle temperament was measured by a chute score (CS, ranging from 1 = calm and not moving to 5 = rearing and violently struggling) and flight speed. Flight speed was measured by two observers to determine how long the animal took to travel 12 feet from the exit of the squeeze chute. Feedlot performance was assessed by body weight (BW) measurements, average …

The Role Of Orexin Receptors In Diurnal Variations In Learning And Memory, Jacob Christian Blotter

Undergraduate Honors Capstone Projects

The brain's ability to learn and remember is a topic of extensive debate and research. Mammals share many similarities, including the way in which information from the outside world is processed and stored. Mammalian circadian rhythms have long been thought to be essentially involved with these processes. Orexin, a neurotransmitter in the brain, plays a crucial role in arousal and circadian rhythm. This study is designed to explore the brain's ability to process and store information at different times of the circadian period, and to explore the role of orexin by comparing the performance of normal (wild-type) mice and abnormal …