Digital Commons Network^™

Descriptive Study Of Adult Male Acheta Domesticus Phonotaxis, Dana Husana

Master's Theses

The phonotactic behavior of male Acheta domesticus has not been described at length. The present study evaluates the phonotactic responses of male A. domesticus in relation to age. Male crickets of different ages (young and old) were exposed to calls with attractive and non-attractive syllable periods for this species. Both age groups exhibited phonotaxis but did not show a preference towards the attractive call over the non-attractive ones. No significant relationship was found between age and phonotactic response. Additionally, no significant differences were observed between age and preferred syllable period. Acoustic responses were also observed in some of the older …

Benthic Habitat Mapping Of Mountain Top Bank Within The Northern Gulf Of Mexico Through Integrated Geophysical And Visual Data Analysis, Bethany Pertain

Master's Theses

Mesophotic coral ecosystems (MCEs) are among the seafloor ecosystems that have been poorly studied throughout the world’s oceans, but they are a vital and diverse ecosystem that should be prioritized for future mapping and ecological studies. Priority should be given to them because they possess natural, social, and economic values, and face a variety of threats, all of which, if not better understood will result in the loss of this unique ecosystem. Insights into these ecosystems, among other deep-sea environments, are lacking due to difficulty accessing them, inherent lag between data collection by an autonomous system and observation by a …

Lichens Of Ultramafic Rocks: A Multidisciplinary Approach To Understanding The Ecology Of An Understudied Organism In A Well-Studied System, Michael Mulroy

Master's Theses

Lichens are among the most prominent and successful life forms of metal-rich habitats, including ultramafic rocks and soils; however, research on lichens of ultramafic habitats is limited, especially on the North American continent. A review of the published literature on lichens of ultramafic substrates in North America yielded a total of 437 lichen species reported from ultramafic rocks and soils. Lichen assemblages of ultramafic substrates vary in composition and are dominated by acidophytic (low pH preferring) taxa with a minor, but consistent, basiphytic (high pH preferring) component. Species lists from ultramafic habitats in different geographic regions varied widely, suggesting that …

Trophic Ecology And Mercury Concentrations Of Canary Rockfish (Sebastes Pinniger) In The California Current System, Michaela M. Melanson

Master's Theses

Canary rockfish are a profitable fishery resource that has failed and successfully recovered in the 21st century. This study aimed to evaluate their trophic ecology through stomach content and stable isotope analysis and relate these to their mercury concentrations, biological traits, and environmental conditions. Canary rockfish consume mostly krill and teleosts with their geographic location affecting the proportion of prey items, suggesting regional environmental effects: chlorophyll-a, relief, port, and depth impact dietary choices. Mean ??13C values (-17.18 ± 0.54) significantly increased in individuals residing in deeper depths, higher latitudes, higher productivity, and higher temperatures, and in sexually mature individuals. Mean …

Habitat Value Of Stormwater Retention Basins For Avian Species In The South San Francisco Bay, Maya D. Briones

Master's Theses

Shorebird populations are declining worldwide due to habitat fragmentation, degradation, and loss. A potential, understudied set of resources that might be used to benefit waterfowl, especially breeding shorebirds, are artificial wetlands such as stormwater retention basins. This study evaluated the habitat value of stormwater retention basins in the San Francisco Bay Area by measuring species abundance, richness, and behavior. Seston, or biota and other suspended material, was collected and tested for mercury contents. Additionally, the habitat features within each basin were recorded and tracked for changes over a year. The stormwater retention basins supported a higher diversity of bird species …

Tree Removal From An Encroached Coastal Grassland Restores Soil Bacterial Communities Before Fungal Communities, Ka Ki Law

Master's Theses

Woody species encroachment depletes historic grassland biodiversity and degrades ecosystem function around the world. In particular, the encroaching trees can shift soil properties and microbial communities, which play critical roles in plant health and global nutrient cycling. Little is known about how removing encroached trees affects soil ecosystems, however. Over the last century, Pinus radiata and Hesperocyparis macrocarpa (non-native to the area) both encroached into coastal prairies at Rancho Corral de Tierra in California, and selected trees were removed in 2017 and 2018 to restore grassland habitats. To examine the impacts of encroachment and removal on the soil ecosystem, I …

Ectotherm Thermoregulation At Fine Scales: Novel Methods Reveal A Link Between The Spatial Distribution Of Temperature And Habitat Quality, Ian Axsom

Master's Theses

Investigating ecological questions at the scale of individual organisms is necessary to understand and predict the biological consequences of environmental conditions. For small organisms this can be challenging because we need tools with the appropriate accuracy and resolution to record and quantify their ecological interactions. Unfortunately, many of our existing tools are only appropriate for medium to large organisms or those that are wide ranging, inhibiting our ability to investigate the ecology of small organisms at fine scales.

In Chapter 1, I tested a novel workflow for recording animal movements at very fine spatial and temporal scales. The workflow combined …

Population Genetics Of Cownose Rays, Rhinoptera Spp. In The Western Atlantic, Helen Weber

Master's Theses

Using molecular tools (e.g., the NADH subunit II mitochondrial gene), this study was the first to document the Brazilian cownose ray, Rhinoptera brasiliensis, within the northwestern Atlantic (NWA), and was the first study to examine population structure in R. brasiliensis within the NWA or northern Gulf of Mexico (GMX), revealing novel insights into the population biology of the animal and extending its range by nearly 1,500 km. This study also examined the sympatrically occurring American cownose ray, R. bonasus, and found population structure between the NWA and the GMX and the NWA and the southwestern Atlantic (SWA). High …

The Shallow Benthic Invertebrate Recovery From The End-Cretaceous Mass Extinction Across The Gulf Coastal Plain, Ronan B. Beltracchi

Master's Theses

The Gulf Coastal Plain, in the southeastern United States, contains several sites with well-preserved fossil assemblages from the Cretaceous- Paleogene boundary (K/Pg). Changes in benthic macroinvertebrate assemblages after mass extinction events commonly include reduction in body size of surviving organisms and preferential survival based on ecospace occupation. This study examines patterns of functional ecology and body size change in mollusk fossils from bulk samples collected throughout the post-extinction recovery interval at a well-studied boundary site from Darting Minnow Creek in Brazos, Texas USA and a recently described K/Pg boundary section on the Ouachita River in Malvern, Arkansas USA. The proportional …

The Modern-Day Effect Of Holc Redlining On Neighborhood Development, Liubov Ivashov

Master's Theses

Racial segregation, which happened more than one hundred years ago in the U.S., is a fundamental cause of economic inequality for people living in historically segregated neighborhoods today. Redlining was one form of federal policy that forced to separate communities by race even more after the Great Depression. The Home Owners Loan Corporation (HOLC) maps are widely used in economic research papers as one of the most comprehensive sources of data available to measure the effect of residential segregation. In this paper, using the Historical Redline Score (HRS) method, the author measured the association between modern-day population distribution, rent prices, …

Research Handling Effects On Stress Hormones, Blood Parameters, And Heart Rate In Juvenile Northern Elephant Seals (Mirounga Angustirostris), Lauren A. Cooley

Master's Theses

Wildlife researchers must balance the need to safely capture and handle their study animals to sample tissues, collect morphological measurements, and attach dataloggers while simultaneously ensuring their results are not confounded by stress artifacts caused by handling. To determine the physiological effects of research activities including chemical immobilization, transport, instrumentation with biologgers, and overnight holding on a model marine mammal species, I collected hormone, blood chemistry, hematology, and heart rate data from 19 juvenile northern elephant seals (Mirounga angustirostris) throughout a translocation experiment. Across my six sampling timepoints, cortisol and aldosterone data revealed a moderate hormonal stress response to handling …

Examining The Ecological And Social Implications Of Parklets And Plazas Across Multiple Urban Scales, Joshua L. Muller

Master's Theses

Faced with population increases but stagnant capital improvements and impacts from global warming, cities around the world are experimenting with smaller-scale and cheaper strategies in order to accommodate the new influx of residents. New York City has led the way in converting low-efficiency intersection space into public plazas with a limited range of permanently installed elements and San Francisco has pioneered the concept of the parklet, which converts two to four street parking spaces into a modular and flexible pedestrian space. I seek to answer two questions about these spaces: What are common factors influencing the viability and successful implementation …

Wicked Problems: Understanding How Cities And Counties In California Are Tackling Climate Change And Homelessness, Guadalupe Michelle Franco

Master's Theses

California continues to endure the detrimental effects of climate change, such as poor air quality, flooding, and heatwaves. Concurrently, the state has seen an increase in the number of unhoused communities due to various ramifications such as rapid urbanization, failed political leadership, and restricted housing policies. While unhoused communities fight to access basic services, they must also now adapt to the looming impacts of climate change. Unhoused populations are especially vulnerable to climate change as they have limited access to shelter, spend the majority of their time outdoors, and lack the economic ability to adapt. While cities and counties are …

Resistance To Rattlesnake Venoms In An Eastern Colorado Rodent Community, Neil Balchan

Master's Theses

The grasslands of eastern Colorado are inhabited by two species of rattlesnakes, the Prairie Rattlesnake (Crotalus viridis) and the Desert Massasauga Rattlesnake (Sistrurus tergeminus edwardsii). An array of rodent species, both native and introduced, also occupy these grasslands, and serve as a varied prey base for the previously listed rattlesnakes. Predator-prey interactions in this system gain an additional level of complexity due to the presence of venoms, a chemical arsenal possessed by both rattlesnakes to incapacitate their prey. Rodents in other systems have demonstrated resistance to snake venoms, and there is potential for a similar dynamic to be present in …

A Floristic Study Of The Cal Poly Swanton Pacific Ranch And A New Combination In Sanicula Crassicaulis (Apiaceae), Sanicula Crassicaulis Var. Nudicaulis, Reed J. Kenny

Master's Theses

Globally we are experiencing a biodiversity crisis and potentially a sixth mass extinction event. Plant specimens are one of the best, most concrete records of biodiversity that we can create. Despite this, the rate of plant collecting has declined steeply since World War II. Now more than ever, plant collections are vital, both for the purpose of quantifying the plant biodiversity in an area and for discovering previously unrecognized diversity.

In Chapter 1, we conducted a floristic survey of the Cal Poly Swanton Pacific Ranch. The Swanton Pacific Ranch (SPR) is located north of the small town of Davenport California, …

The Effects Of Prescribed Burning And Microhabitat Type On Ant (Formicidae) Functional Groups And A Survey Of Ants In The Dr. Howard Reynolds Nature Area (A Mixed Grass Prairie), Ashley N. Durr

Master's Theses

This project sought to understand how prescribed burning and microhabitat type impacts Kansas ant functional groups and also whether prescribed burning in different microhabitat types altered the burn’s impact on those functional groups. The Dr. Howard Reynolds Nature Trail, located in Hays, Kansas, was burned in the spring of 2019. The area consists of 2 distinct habitat types: a dry, mixed-grass dominated uphill area and a moist, densely vegetated downhill area. Pitfall trapping was conducted during the summers of the year prior to the burn (2018) and the year following the burn (2019). 15 pitfall traps were spread across each …

Development And Employment Of Environmental Dna Methods For The Detection Of Bull Sharks (Carcharhinus Leucas) In A Freshwater And Estuarine Interface In The Mobile-Tensaw Delta And Mobile Bay, Alabama, Katherine Schweiss

Master's Theses

Species conservation and management is influenced by the quality of monitoring methods employed, especially when targeting elusive, but ecologically significant species, like elasmobranchs. Bull Sharks (Carcharhinus leucas) are highly mobile predators that rely on estuaries and freshwater rivers for maturation, resources, and refuge; their ability to withstand changing environmental conditions may mean they are linking ecosystems through their habitat usage and movements. Rather than setting nets or attaching acoustic monitoring devices, which can be expensive, time-consuming, and invasive, the analysis of environmental DNA (eDNA) for tracing species presence was used to target C. leucasDNA. The present research …

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

The Effect Of Historic Shipwrecks On Sediment Microbiomes In The Northern Gulf Of Mexico, Melissa Brock

Master's Theses

Microorganisms are ubiquitously distributed across all aquatic habitats, but it is the environmental conditions of a habitat that determine which microorganisms can thrive in terms of abundance or metabolic activity. Habitats that experience consistent physical and chemical environmental conditions repeatedly favor specific taxonomic groups which may result in a microbial assemblage that is commonly associated with that habitat (i.e., a core microbiome). Core microbiomes have been identified for a variety of natural marine habitats including methane seeps, wood falls, octocoral, and deep-sea sediments. However, it was unknown if the presence of man-made structures on the seafloor, including historic shipwrecks, also …

Dynamics And Ecological Implications Of The Ulva-Zostera Ecotone In Elkhorn Slough, California, María Vila Duplá

Master's Theses

Ecotones are transitional areas between adjacent ecological communities that have unique ecological qualities defined by space and time scales, and by the interactions between adjacent systems. Ecotones play an essential role in supporting biologically diverse communities, and are sensitive indicators of global change. An Ulva-Zostera ecotone extends along the northern shore of Seal Bend in Elkhorn Slough, an estuary located in central California. Although previous studies have mentioned the presence of the Ulva-Zostera ecotone, this was the first study to focus on understanding its driving factors, spatiotemporal dynamics, and overall ecological implications. A combination of habitat monitoring, water quality assessments, …

Comparative Thermal Ecology Of Coastal And Inland Pacific Rattlesnakes (Crotalus Oreganus), Hayley Layne Crowell

Master's Theses

Global biodiversity is declining as a direct result of anthropogenic climate change. Ectothermic species have become focal organisms for studying the ecological effects of altered climates due to the clear relationship between environmental temperatures and ectotherms’ basic physiological functions. Historically, examinations of these effects have focused heavily on heliothermic lizards, and most others have tended to focus on single populations or sympatric species within a single community. Addressing the longterm energetic implications of environmental temperature variation will provide valuable insight into the cascading physiological effects that certain populations or species may experience as a result of altered climates.

In this …

The Impact Of Junk Food Marketing Regulations On Food Sales: An Ecological Study, Yumi Kovic

Master's Theses

Objectives. To evaluate the impact of junk food marketing policies implemented worldwide from 2003 through 2014 on nationwide junk food sales and to identify the most effective policy characteristics in reducing junk food sales.

Methods. Junk food marketing policy data were obtained and categorized through a thorough literature review. These data were analyzed using a repeated measures design against EuroMonitor junk food sales data from 2002 and 2016.

Results. Countries with junk food marketing policies saw a decrease in junk food sales after implementation, while those without said policies saw an increase in sales. Countries with statutory policies saw a …

Ectoparasite Presence In Select Northcentral Kansas Bat Species, Elizabeth Schumann

Master's Theses

Working with other graduate students on a grant given to Fort Hays State University, from the Kansas Department of Wildlife, Parks and Tourism, I looked at presence and species of ectoparasites on bat species. The main goal of our grant was to quantify and qualify the status of the northern myotis (Myotis septentrionalis) in the state of Kansas, and to record data on any bycatch. I worked on our grant in the summer field seasons of 2016 and 2017, May to October, as described by the Indiana bat protocol.

Bats were captured by using mist nets set over …

Characterizing Ecological And Genetic Patterns Of The Colonizing Species Dubautia Scabra On The Big Island, Hawaii, Samantha Kaleigh Naibauer

Master's Theses

The Hawaiian Silversword Alliance (HSA) is a group of approximately 35 endemic species found on the Hawaiian Islands. The HSA is of particular interest due to the vast adaptive responses of its members across the Hawaiian Islands. Each of these plant species is generally limited to a very specific habitat type with a unique morphology and physiology. Dubautia scabra is the first angiosperm colonist of new lava flows, arriving in as few as two years after lava cools. The critical role D. scabra plays in this ecosystem gives a unique starting point for understanding downstream ecological processes such as seed …

Cold Acclimation Response Of Non-Native Italian Wall Lizard (Podarcis Siculus) Populations From New York And California, Daniel Haro

Master's Theses

Understanding how organisms respond to climatic variability and novel conditions is becoming an increasingly important task for ecologists. For ectotherms in the northern hemisphere, the response to cold is of special interest, considering that poleward range expansion events and increasing variability of temperatures during winter are already being observed as consequences of a warming planet. Though direction of change in physiological variables in response to cold is well studied in ectotherms, the extent to which traits can change and the rate at which they can change is not.

We compared the extent and rate of change in cold tolerance (CT …

Diets And Stable Isotope Signatures Of Yellowtail Rockfish (Sebastes Flavidus) In Central California, Jennifer Chiu

Master's Theses

Studies of fish diets can improve the understanding of trophic distributions and the predatory role of a species in an ecosystem. Identifying the spatial and temporal variability in the diets of fishes can provide useful information for stock assessments and management. Yellowtail Rockfish (Sebastes flavidus) are a commercially and recreationally important fishery species, and abundant along the central California coast, yet the most recent studies of diets occurred over 20 years ago in Oregon and Washington. To provide current information from California, I examined the food habits of Yellowtail Rockfish collected near Cordell Bank, the Farallon Islands, and Half Moon …

Opioid Use And Opioid Use Disorder Services In Connecticut, Julie Christensen

Master's Theses

No abstract provided.

Identification And Characterization Of Tri-Colored Bat Hibernaculum In Russell County, Kansas, Angelica Sprague

Master's Theses

Caves are often essential during hibernation, a sensitive stage in the life cycle of bats. Caves offer more stable conditions, such as temperature and relative humidity, during the changing seasons when food supply is limited, and weather is unstable. As caves in North-Central Kansas are sparse, the hibernating status of tri-colored bat (Perimyotis subflavus) is not well known. Bats are experiencing substantial population declines within the United States, caused primarily by white nose-syndrome, as well as habitat loss and degradation, and increased wind-power facilities. In the winter seasons of 2015 and 2016, I studied tri-colored bat hibernacula. A man-made “cave” …

Diet And Activity Patterns Of Five Bat Species In North-Central Kansas, Holly G. Wilson

Master's Theses

My study focuses on six bat species that occur in north-central Kansas. Although each species is widely distributed, information about their diet and activity patterns is lacking, especially within Kansas. Increased knowledge about bat species in Kansas can provide a baseline for future studies and conservation efforts for the species included in my study; big brown bat (Eptesicus fuscus), eastern red bat (Lasiurus borealis), hoary bat (Lasiurus cinereus), northern myotis (Myotis septentrionalis), evening bat (Nycticeius humeralis), and tricolored bats (Perimyotis subflavus) were captured and fecal samples were examined for diet diversity. I captured bats in mist nets in the Kansas …

Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon

Master's Theses

Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure …