Life Sciences Commons^™

Population Physiology, Demography, And Genetics Of Side-Blotched Lizards (Uta Stansburiana) Residing In Urban And Natural Environments, Spencer B. Hudson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife populations across the globe are poised to lose their natural habitat to urbanization, yet there is limited information on how different species handle living in cities. Animals in urban environments are often susceptible to novel stressors, which can threaten their individual health and population viability. The physiological characteristics of animals, such as those related to metabolic hormones, oxidative stress, and immunity, are expected to be important for survival in this context. If so, animals persisting in urban areas may demonstrate physiological differences from their natural counterparts, perhaps due to evolutionary change. These potential outcomes have been documented in birds …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

The Effects Of Diatom-Specific Polyunsaturated Aldehydes On Larval Zebrafish (Danio Rerio), Rachel Raymer

WWU Graduate School Collection

Diatoms are ubiquitous in marine planktonic and benthic environments and are common in diets for many lower-trophic organisms. Certain species of diatoms produce polyunsaturated aldehydes (PUAs) that can exist in particulate and dissolved forms. Diatom PUAs are known for negatively affecting the fecundity of their primary consumers, including invertebrate grazers like copepods and echinoderms. However, little is known about the effects of diatom PUAs on vertebrates that may be exposed to dissolved or ingested PUAs due to overlapping distribution with diatom populations. The purpose of this study was to test whether dissolved diatom PUAs affect the early life stages of …

Corbicula Fluminea Effects On Survival, Growth, And Drift Of Juvenile Lampsilis Siliquoidea In Laboratory Exposures, Allison Nicole Sieja

MSU Graduate Theses

The Asian clam, Corbicula fluminea, is an invasive species that is abundant and often co-occurs with native freshwater mussels. Corbicula is widely suspected of having negative effects on native mussels, but few studies have empirically tested this hypothesis. I used laboratory experiments to evaluate how adult Corbicula affected the survivorship, growth, and drift of juvenile Lampsilis siliquoidea. Survival and growth of newly metamorphosed mussels were tested in downwelling flow-through chambers with glass-bead substrate. Treatments were control (no clams), small adult clams, or large adult clams. After 28 days, large clams slightly but significantly reduced the number of juveniles …

A Reintroduction Retrospective: Comparative Fisher (Pekania Pennanti) Survival And Prey Habitat Use In The Cascade Mountains Of Washington State, Tanner S.T. Humphries

Graduate Student Theses, Dissertations, & Professional Papers

Increasing human impacts on biodiversity highlight the global need for ecological restoration. For many wildlife species, reintroduction is necessary to re-establish populations in parts of their historic range where they have been extirpated. Reintroduction efforts are commonly used to help restore ecosystem integrity, but are often expensive, time consuming, and unsuccessful at generating self-sustaining populations. Thus, a more complete understanding of the factors affecting restoration success is important for ensuring successful outcomes and responsible stewardship. Fishers (Pekania pennanti) are one of the most commonly reintroduced carnivores in North America, but the success of such efforts is highly variable, …

The Incorporation Of Lipids Into The Cellular Membrane Of Salmonella, Betsy H. Redfern

Honors Theses

Salmonella is a gram negative, facultative anaerobic food borne pathogen and is the leading cause of deaths related to food borne illnesses. In order to establish an infection successfully, Salmonella must be able to survive in the presence of various stressors that it encounters, namely changes in pH, oxygen availability, osmolarity and bile. Previous research has shown that exposure to bile causes a shift in fatty acid composition in the cell membrane of the enteric bacterium Enterococcus faecalis. Thus, this led to the hypothesis that Salmonella incorporates fatty acids into its cellular membrane following exposure to bile and thereby protects …

Population Dynamics And Demographics Of Spotted Seatrout, Cynoscion Nebulosus, Through Spatial Analysis: Towards An Integrative Management Approach, Ashley Melancon Baer

LSU Doctoral Dissertations

Spotted seatrout (Cynoscion nebulosus) is one of the most highly prized sportfish along the Gulf of Mexico coast, particularly in Louisiana. Although spotted seatrout are considered to be well managed and sustainably fished according to the state’s most recent stock assessment, the spatial ecology of this species is largely understudied in Louisiana waters. Acoustic telemetry is an innovative technology that is commonly used to assess the movements and behavior of aquatic species, and can be used as a tool to address the paucity of information on the spatial dynamics of spotted seatrout. The focus of this study was …

Canis Lupus (Gray Wolf) Pup Survival In Yellowstone National Park, Anne Marie Jehle

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The aim of this study was to describe gray wolf (Canis lupus) pup survival rates throughout the summer months in Yellowstone National Park. Understanding pup survival has implications for trends in pack and population age structure, cooperative breeding ecology and other breeding tendencies, social hierarchies, and population fitness, among other elements of species-specific population ecology. A general understanding of trends in pup survival is also relevant to state and federal land that allow gray wolf harvest. Understanding such trends and survival ecology gives managers and biologists the opportunity to evaluate gray wolf populations at a more comprehensive level and implement …

The Role Of Genomic Versatility In Multi-Niche Preferences Of Escherichia Coli, Gitanjali Nandakafle

Electronic Theses and Dissertations

Escherichia coli strains are naturally present as either commensals or pathogens in the gastrointestinal tract of mammals and some other vertebrates. Until recently, it was assumed that E. coli are solely associated with the gut and are unable to survive outside of a host for a long period of time, the basis of its use as an indicator organism. Recent reports suggest that E. coli can become naturalized to several tropical, subtropical or temperate soils and aquatic environments, where they have been isolated repeatedly. Several studies have shown that these strains are capable of surviving and proliferating in the environment …

Resource Selection, Survival, And Departure Of Adult Female Mallards From The Lake St. Clair Region During Autumn And Winter, Matthew Palumbo

Electronic Thesis and Dissertation Repository

During autumn and winter, mallards (Anas platyrhynchos) maximize fitness through their spatiotemporal distribution to avoid mortality risks while balancing trade-offs to access foods to undergo migration and maintain homeostasis. Thousands of mallards use Lake St. Clair as it is an important, but threatened, migratory staging area in the Great Lakes. My goal was to understand how mallards were selecting resources in the region and potential relationships of selection strategies. My objectives were to estimate resource selection of adult female mallards, in relation to perceived risk of hunting mortality, and determine if selection strategies were related to survival and …

Seasonal Ecology Of Mottled Sculpin And Brown Trout In A Coldwater Michigan Stream, Susanna K. Lagory

Masters Theses

In temperate regions, environmental conditions vary distinctly between seasons. This variation can strongly impact in-stream environmental conditions. Winter is often thought to be harsher than other seasons for stream fishes, given the adverse environmental conditions that arise from low temperatures during winter in temperate regions. Low temperatures, episodic elevated discharge, and ice formation associated with winter are hypothesized to reduce movement, body condition, and survival of stream fishes. However, few studies test this hypothesis through formal comparisons, and most studies of seasonal stream fish ecology focus on salmonids. To address this knowledge gap, I estimated and compared body condition, net …

Nest-Site Selection And Neonate Survival Of Eastern Box Turtles (Terrapene Carolina Carolina) In Michigan’S Northern Lower Peninsula, Joseph T. Altobelli

Masters Theses

Turtles (Order Testudines) are experiencing global declines largely due to anthropogenic influences such as habitat fragmentation, illegal collection and sales, and the threat of global climate change. Removal of individuals from the adult age-classes means there is now a greater need to understand the survival of neonate and juvenile turtle age-classes. In this study I examined a population of eastern box turtles (Terrapene carolina carolina) at the northern limit of their range in Michigan’s lower peninsula. The objectives of my thesis were 1. to determine the microhabitat factors that influence nestsite selection by female box turtles and how …

Abiotic Factors Contributing To The Survival Of Three Tick Species In Southeastern Virginia, Amblyomma Americanum (Lone Star Tick), Dermacentor Variabilis (American Dog Tick), And Amblyomma Maculatum (Gulf Coast Tick), Lindsey A. Bidder

Biological Sciences Theses & Dissertations

Amblyomma americanum, Amblyomma maculatum, and Dermacentor variabilis are hard-bodied ticks in the Hampton Roads area of southeastern Virginia. This study consisted of two field projects focused on these tick species. To estimate the off-host survival of local tick species, a capture-mark-recapture (CMR) study was performed. An environmental survival study was performed to quantify the ability of these three tick species to survive in situ. Four field sites were used in the Hampton Roads region covering a variety of habitat types and vegetation; specifically two drier, upland field sites and two flood-prone sites. CMR was conducted from May through …

The Role Of Oncogenic Kras In Initiation, Progression And Maintenance Of Pancreatic Cancer, Nirakar Rajbhandari

Theses & Dissertations

Pancreatic cancer is a lethal disease that is almost invariably associated with a KRAS gene mutation. Due to a very high frequency of gain-of-function mutations within the KRAS gene, and its proven role in initiation of pancreatic cancer in animal models, mutant KRAS is considered a rational therapeutic target. To determine the potential role of oncogenic KRAS in pancreatic tumor maintenance in vivo, we generated a mouse model with a Doxycycline regulated expression of oncogenic KRAS (KRAS^G12D) in pancreas. Using this reversible model, we demonstrated that the expression of oncogenic KRAS in a Cdkn2a deficient background was …

Evaluation Of Natural Steelhead Recruitment In The Muskegon River, Michigan, Nicholas C. Albrecht

Masters Theses

The lower Muskegon River is one of the most heavily fished rivers in the state of Michigan and is a valuable component of the multi-billion dollar sport fishery in the Great Lakes. Although significant stocking effort has been invested to maintain and improve the steelhead (Oncorhynchus mykiss) fishery in the Muskegon River, natural recruitment has been severely limited due to high summer water temperatures. The goal of this research project was to evaluate the success of a diffuser system installed in 2008 at Croton Dam to moderate high summer water temperatures in the lower Muskegon River. I estimated natural juvenile …

The Effects Of Soil Ph And Texture On The Molting Success And Survival Of Blacklegged Ticks (Ixodes Scapularis): A Field Experiment, Colleen Cook

Honors Theses

The blacklegged tick (Ixodes scapularis) is the primary vector of Borrelia burgdorferi, the causative agent of Lyme disease. When a tick is not questing or feeding, the majority of its life is spent within the soil. Abiotic factors within soil have been shown to affect tick molting and survival across all life stages. Soil pH, however, has not been heavily investigated. In this field study, I investigated the effects of soil pH and texture on engorged nymphal ticks. Two sites were chosen to encompass the extremes of soil pH in the region; the Albany Pine Bush in Albany, NY has …

Survival, Abundance, And Geographic Distribution Of Temperate-Nesting Canada Geese (Branta Canadensis) In Arkansas, Margaret Eliese Ronke

Graduate Theses and Dissertations

Temperate-nesting Canada geese in Arkansas have grown in abundance and range since reintroduction in the 1980s. The Arkansas Game and Fish Commission uses harvest and other methods to maintain the population at desired levels. However, continued management of temperate-nesting geese requires knowledge of the population's demographics and current range to help establish quantifiable management goals.

To assess the need and effect of changing hunting regulations, survival and recovery rates and abundance were estimated for this population. Annual survival rates of temperate-nesting Canada geese banded and recovered in Arkansas from 2005 to 2011 were estimated using the Burnham joint live-dead recovery …

Nest Survival Of Grassland Breeding Birds In A Southern Mixed-Grass Prairie Wetland, Clinton Helms

Master's Theses

As a group, grassland birds have been declining significantly since European settlement of the prairie. The subsequent plowing of the prairie by settlers was compounded by fire suppression, resulting in a patchwork of cultivated fields with intermittent tracts of overgrown grassland. Over an interval of ~200 years, these practices lead to an estimated decline of 96 % of native tallgrass prairie habitat. Due to the imperiled status of grassland birds, an emphasis has been placed on managing for this particular group throughout the southern mixed-grass prairie region. I investigated the effects of adaptive three-pasture rotational grazing treatments (3ROT) versus traditional …

Survivorship Of Ploidy-Variable Unisexual Ambystoma Aalamanders Across Developmental Stages, Christina Marie Casto

Master's Theses and Doctoral Dissertations

Unisexual Ambystoma produce ploidy-variable offspring that differ in survivorship to adulthood. These populations reproduce through kleptogenesis, persisting by stealing genetic material from males of compatible bisexual Ambystoma species (e.g., Jefferson's Salamander A. jeffersonianum, and the Blue-Spotted Salamander A. laterale). Kleptogenesis can result in ploidy-variable embryos within an egg mass because the female may or may not incorporate the male ambystomatid genome. Little is known about the survivorship of ploidy-variable individuals. In previous studies, triploid individuals are the most abundant class, suggesting a greater mortality in high-ploidy (tetraploid and pentaploid) individuals. We assessed the frequency of ploidy levels (determined …

Population Demographics And Genetics Of Spix's Disk-Winged Bat: Insights Regarding Survival, Mate Choice, Gene Flow And Effective Population Size, Michael Buchalski

Dissertations

Simultaneous study of the demographics and genetics of populations are relatively rare within the literature, despite insights their combined use offers regarding the life history, ecology, and evolution of species. Here I take a comprehensive approach, using capture-recapture data, polymorphic microsatellite markers, and various modeling techniques to examine the demographics and genetics of multiple local populations of Spix’s disk-winged bat (Thyroptera tricolor) in southwestern Costa Rica. T. tricolor is a highly gregarious, neotropical bat species known to form kin-based social groups with high retention of offspring of both sexes. The implications of this highly unusual social structure for …

Occurrence, Survival, And Persistence Of The Fecal Indicator Bacterium, Enterococcus Mundtii, In Soils Of A Contaminated Watershed, Marc Carpenter

Masters Theses, 2010-2019

The Clean Water Act of 1972 raised awareness of the extent of the pollution in U.S. waters and the need for monitoring and identifying sources of contamination. Surface water quality is routinely evaluated using fecal indicators, such as Enterococcus spp. Recent studies in a south Texas watershed showed that fecal bacteria were being transported to water via agricultural land runoff following rainfall, suggesting that soil may be a source of these bacteria. In this study, soils from fields under different crop covers were sampled to determine seasonal levels of enterococci and species of enterococci were identified using the BIOLOG™ Microbial …

The Role Of Receptor Tyrosine Kinase Axl In Pancreatic Ductal Adenocarcinoma And Its Regulation By Hematopoietic Progenitor Kinase 1, Xianzhou Song

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies with less than 5% of five year survival rate. New molecular markers and new therapeutic targets are urgently needed for patients with PDA. Oncogenic receptor tyrosine kinase Axl has been reported to be overexpressed in many types of human malignancies, including diffuse glioma, melanoma, osteosarcoma, and carcinomas of lung, colon, prostate, breast, ovary, esophagus, stomach, and kidney. However, the expression and functions of Axl in PDA are unclear. We hypothesized that Axl contributes to the development and progression of PDA. We examined Axl expression in 54 human PDA samples …

Factors Related To Nest Survival And Over-Winter Survival Of A Northern Bobwhite (Colinus Virginianus) Population In Southwest Florida, Steven Kenneth Brinkley

Masters Theses

The northern bobwhite (Colinus virginianus) is a gallinaceous upland game bird dependent on early successional grassland habitat for reproduction and survival. Bobwhite populations have been declining range-wide for nearly a half century. The habitat of Babcock-Webb Wildlife Management Area (BWWMA) in southwest Florida is mostly virgin, early successional grassland and pine flatwoods. Although BWWMA is located in the far southern end of the bobwhite range, the area is a popular public land for bobwhite hunting. The BWWMA bobwhite population has declined evidenced by a dramatic decrease in harvest over the last 20 years. The two objectives of my …

Treefrog (Hyla Squirella) Responses To Rangeland And Management In Semi-Tropical Florida, Usa, Kathryn Windes

Electronic Theses and Dissertations

As urban areas expand, agricultural lands become increasingly important habitat for many species. Compared to some types of agricultural land-use, ranchlands provide vast expanses of minimally modified habitat that support many threatened and endangered species. Conservation biologists can promote ecologically sound management approaches by quantifying the effects of agricultural practices on resident species. I examined the effects of pasture management, cattle grazing, and landscape characteristics on both adult and larval treefrogs in a ranchland in south-central Florida. I experimentally determined optimal deployment of artificial treefrog shelters constructed of polyvinylchloride (PVC) pipe to efficiently sample adult treefrogs (Chapter 1). Seventy-two shelters …

Landcover Change And Population Dynamics Of Florida Scrub-Jays And Florida Grasshopper Sparrows, David Breininger

Electronic Theses and Dissertations

I confronted empirical habitat data (1994-2004) and population data (1988-2005) with ecological theory on habitat dynamics, recruitment, survival, and dispersal to develop predictive relationships between landcover variation and population dynamics. I focus on Florida Scrub-Jays, although one chapter presents a model for the potential influence of habitat restoration on viability of the Florida Grasshopper Sparrow. Both species are unique to Florida landscapes that are dominated by shrubs and grasses and maintained by frequent fires. Both species are declining, even in protected areas, despite their protected status. I mapped habitat for both species using grid polygon cells to quantify population potential …

Density Effects On Growth, Survival And Diet Of June Sucker (Chasmistes Liorus): A Component Allee Effect In An Endangered Species., David Barrett Gonzalez

Theses and Dissertations

Density-dependence is considered one of the most important regulators of population growth, and it has been documented across a wide variety of species. Typically, population growth rate and components thereof decline with increasing density (i.e., negative density-dependence); however, in species that exhibit high population densities and social behavior, positive density-dependence (i.e., Allee effect) may occur at low density. June sucker, a federally endangered lake sucker endemic to Utah Lake, Utah, USA, occurred historically at high density, and it exhibits coordinated feeding behavior. These characteristics indicate a potential for the existence of an Allee effect at current low population densities. To …

Short-Eared Owl Post-Fledging Survival And Breeding Season Diet, Thomas A. Rivest

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

My research primarily focused on the survival of short-eared owls (Asio flammeus) from leaving the nest until their emigration from their natal territories during 1993 and 1994. I attached tarsal-mounted radio transmitters to nestlings prior to fledging. Of 25 fledgling short-eared owls monitored, 16 (64%) died prior to dispersal and one (4%) died after dispersing. Mammalian predation (5, 29.4%) was the primary cause of mortality followed by starvation (4, 23.5%), exposure (2, 11.8%), auto collision (1, 5.9%), burial (1, 5.9%), and unknown causes (4, 23.5%). Hatch date was found to be negatively correlated with fledgling survival.

A secondary …