Digital Commons Network^™

The Ecological Importance Of Extrinsic And Intrinsic Drivers Of Animal Movement, Josh Earl Rasmussen

Theses and Dissertations

The movement of individuals is foundational to many ecological processes. For example, the movement of an organism from one place to another alters population density at both sites and has potential for affecting the genetic dynamics within the new population. Individual movement events may be in synchrony with overall trends in populations, e.g. spawning migrations, or may be atypical (asynchronous). This latter movement type can affect population and metapopulation dynamics, depending on its prevalence within a population. Nevertheless, given the complexity of interactions, the causative factors of movement are understood vaguely, much less for aquatic organisms. Drivers of movement are …

Detection Of Tick-Borne Bacterial Agents In Lone Star Ticks (Amblyomma Americanum) And Various Wildlife In Mississippi, Ashley Harris Castellaw

Theses and Dissertations

Two studies were conducted to evaluate the presence of tick-borne bacterial agents in Amblyomma americanum, lone star tick (LST), and various wildlife in Mississippi. Adult LSTs had DNA evidence of Ehrlichia chaffeensis (3.7%), E. ewingii (6.3%), and Borrelia lonestari (2.6%), while both larval (24.3%) and adult (43.5%) LSTs were positive for a Rickettsia spp. by polymerase chain reaction (PCR). White-tailed deer (WTD) were the only wildlife PCR positive for E. chaffeensis (18.8%), B. lonestari (3.1%), and Anaplasma phagocytophilum (3.1%). In addition, WTD had the highest seroprevalence to B. lonestari (19.3%) and E. chaffeensis (43.9%) antigens while raccoons had the highest …

Biogeochemistry Of Microbial Mats From A Hypersaline Pond And Reef Biofilm From A Modern Coral Reef, The Bahamas, Mary Keith Puckett

Theses and Dissertations

Biofilm communities host complex biogeochemical processes and play a role in the formation of many carbonate rocks by influencing both carbonate precipitation and dissolution. In this study, the biogeochemistry of microbial mats from a hypersaline pond and biofilm from a coral reef are described using SEM, microelectrode profiling, Biolog, fatty acid methyl ester (FAME) and carbon nitrogen analysis. Results show that the microbial mats are distinctly layered, having an oxic upper portion and an H2S-rich lower portion. The most significant conclusions are that the mats have exceptionally high TOC values and display significant differences in microbial communities present, both between …

From The Bronx Into The Wild! My Adventurous Experience At The Bronx Zoo, Lauren Noll

Student Theses 2001-2013

Many people defend zoos, claiming that they provide great opportunities in education, scientific research, and the overall preservation of wildlife worldwide. However, many people will take the opposing side, arguing that it is wrong to deprive animals of their natural habitats and lifestyles. One of the greatest controversies of our time pertains to the moral issues associated with keeping animals in captivity, such as in zoos and aquariums.

Extraction And Analysis Of Coral Reef Core Samples From Broward County, Florida., Anastasios Stathakopoulos

HCNSO Student Theses and Dissertations

The reefs off Broward County exist as three shore-parallel, sequentially deeper terraces named the "inner", "middle", and "outer" reefs and also a shallower, nearshore ridge complex. These structures span the continental coast of southeast Florida from Palm Beach County to southern Miami-Dade County and were characterized as relict, early Holocene shelf-edge and mid-shelf reefs along with limestone ridges. Presently, the reefs are colonized by a fauna characteristic of West Atlantic/Caribbean reef systems. Scleractinian coral cover is low except for a few dense patches of Acropora cervicornis, while Acropora palmata is absent except for a few individual living colonies.

Coral …

Population Ecology And Reproductive Biology Of The Diamondback Watersnake, Nerodia Rhombifer (Serpentes: Colubridae), In Southernmost Texas, Ruben D. Zamora

Theses and Dissertations - UTB/UTPA

Nerodia rhombifer is a polytypic, semi-aquatic snake with a broad geographical distribution ranging from the American Midwest southward to Chiapas, Mexico. Although relatively abundant throughout much of its range, few ecological studies of the species have been conducted. This study provides basic population ecology information in a subtropical habitat. Population data were obtained in a mark-recapture study at Santa Ana National Wildlife Refuge, Hidalgo County, Texas, from August 1995 to December 1998. Specimens taken elsewhere in Hidalgo County provided information on the reproductive biology. This study provides the first absolute density estimates from anywhere within the species’ range. Quantitative information …

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …

Ecological Effects Of Genotypic Diversity On Community And Ecosystem Function, Megan K. Kanaga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genotypic diversity within populations can have important evolutionary consequences, but the ecological effects of intraspecific genetic variation on community and ecosystem function have only been studied in a few systems. I present the results of a three-year study designed to address the ecological impacts of genotypic diversity in quaking aspen (Populus tremuloides Michx.), using aspen genotypes planted across genotypic diversity levels (monoculture and mixture) and watering treatment levels (well-watered and water-limited). First, I demonstrated that significant variation exists among genotypes for a wide range of growth, morphological and physiological traits, and quantified high heritability and coefficient of genetic variation …

Mining And Residential Development Interact To Produce Highly Impaired Stream Conditions In An Intensively Mined Appalachian Watershed, Eric Richard Merriam

Graduate Theses, Dissertations, and Problem Reports

Large scale surface mining in southern West Virginia causes significant alteration of headwater stream networks. It is unclear, however, the extent to which mining interacts with other stressors to determine physical, chemical, and biological conditions in aquatic systems downstream. Through a watershed scale assessment of Pigeon Creek, the specific objectives of this study were to: (1) quantify the direct and interactive effects of mining and residential development on in-stream conditions; and (2) identify landscape thresholds above which biological impairment occurs. Our results indicate high levels of impairment to habitat, water quality, and benthic invertebrate communities within this watershed. Statistical analyses …

Investigating The Maintenance Of The Lyme Disease Pathogen, Borrelia Burgdorferi, And Its Vector, Ixodes Scapularis, In Tennessee, Michelle Erin Rosen

Masters Theses

Lyme disease (LD), caused by the bacterium Borrelia burgdorferi and transmitted by blacklegged ticks (Ixodes scapularis), is the most commonly reported vector-borne disease in the United States. Lyme disease is endemic in northeastern states, whereas southern states report far fewer cases. This research evaluated the potential LD health risk to humans associated with blacklegged ticks in Tennessee.

I surveyed 1,018 hunter-harvested deer from 71 counties in fall 2007 and fall 2008. Of these, 160 (15.7%) from 35 counties were infested with I. scapularis — 30 of the counties were new distributional records for this species.

I also evaluated …

Non-Calanoid Copepods At The Bermuda Atlantic Time-Series Study (Bats) Station: Community Structure And Ecology, 1995-1999, Hussain Ali Al-Mutairi

USF Tampa Graduate Theses and Dissertations

Zooplankton were sampled on a monthly basis at the Bermuda Atlantic Time-series Study (BATS) site from January 1995 to December 1999. Samples were collected using a 1-m², 200 µm mesh net. The net sampled the water column in an oblique manner from the surface to a mean depth of 200 m. One day and one night tow from each cruise was examined microscopically to determine the community structure of the non-calanoid copepods. In addition, a three year set of nighttime samples were examined taken by 0.5-m², 20 and 35 µm mesh nets (1995-1996 and 1997, respectively) towed obliquely to 150 …

Interaction Topologies And Information Flow, Joshua Payne

Graduate College Dissertations and Theses

Networks are ubiquitous, underlying systems as diverse as the Internet, food webs, societal interactions, the cell, and the brain. Of crucial importance is the coupling of network structure with system dynamics, and much recent attention has focused on how information, such as pathogens, mutations, or ideas, ow through networks. In this dissertation, we advance the understanding of how network structure a ects information ow in two important classes of models. The rst is an independent interaction model, which is used to investigate the propagation of advantageous alleles in evolutionary algorithms. The second is a threshold model, which is used to …

Using Pcr Amplification And Genetic Sequence Analysis Of 18s Rrna Genes To Survey The Microbial Diversity And Distribution Of Eukaryotic Microbes Inhabiting Two Thermo-Acidic Streams In Yellowstone National Park, Wyoming, Robert Harvey Jr.

University of New Orleans Theses and Dissertations

A cultivation-independent approach, sequence analysis of 18S rRNA genes PCR-amplified from environmental DNA, was used to explore the diversity and distribution of eukaryotic microbes inhabiting algal mats in two acidic geothermal streams in Yellowstone National Park. The objectives were to: (1) clarify the identity of mat forming algae in Nymph Creek (2) survey microbial species in the Nymph Creek mat over seasonal intervals along a thermal gradient (3) compare microbial species in the Nymph Creek mat with those in Alluvium Creek mats (4) evaluate microbial species in algal mats formed on different substrates in Alluvium Creek. The results show that …

Treadmill Workstations: An Obesity Intervention?, Dinesh John

Doctoral Dissertations

The purpose of this dissertation was to examine the feasibility and effectiveness of treadmill workstations as a weight loss intervention. Specific aims were (a) to determine if walking while working at a treadmill workstation affects selective attention and mental processing speed, and performance of simulated office work tasks involving fine motor movements (typing and mouse movements) and mathematical and verbal reasoning, and (b) To determine if using of a treadmill workstation favorably influences anthropometric, body composition, cardiovascular, metabolic, musculoskeletal, and mental stress variables in overweight and obese office workers.

For the first aim, 20 participants completed tests to assess selective …

Associations Of Behavioral Profiles With Social And Vocal Behavior In The Carolina Chickadee (Poecile Carolinensis), Ellen H. Williams

Doctoral Dissertations

The research described here tested for relationships among behavioral consistency, personality traits, and communicative behavior in a socially and vocally complex avian species, the Carolina chickadee (Poecile carolinensis). First, I tested for the existence of behavioral profiles, also known as non-human animal personality, across varying contexts (presence of predator, foraging within a novel object, and novel conspecific) in the laboratory. I found evidence for behavioral profiles encompassing behavioral patterns such as activity, affiliation, aggression, and boldness. Second, I incorporated a larger social component to these studies by testing birds housed in social groups in semi-naturalistic aviary settings. In …

The Effects Of Physical Activity And Nutrient Intake On The Risk Of Hip Fracture : Results From The Adventist Health Study-2, Wen-Ling Liao

Loma Linda University Electronic Theses, Dissertations & Projects

This is a two year of follow up study of Adventist Health Study-2 (AHS-2). We assessed the association between physical activity, nutrient intake and risk of hip fracture among peri- and post menopausal Caucasian women using unconditional logistic regression models. All subjects completed a lifestyle questionnaire which including information of physical activity and frequency and portion size of food intake at enrollment into the study (2002-2007). The “Bi-Annual Hospitalization History” questionnaire which included a question about hip fractures due to minor trauma/falls was sent to subjects approximately two years after enrollment, with a response rat of 82.84%. In this cohort, …

Introduction And Spread Of Bromus Tectorum (Cheatgrass) Into Midwestern United States: Population Genetic And Evolutionary Consequences, Temsha D. Huttanus

Boise State University Theses and Dissertations

High propagule pressure is correlated with invasion success, and has important implications for the genetic diversity and evolutionary potential of a species in its introduced range. Here, I examine an invasive annual grass Bromus tectorum and document the population genetic consequences that resulted from multiple introductions of genotypes native to different Eurasian regions into the North American Midwest. Herbarium collections showed that B. tectorum was first recorded near-contemporaneously throughout the Midwest in the late 1800s. Allozyme diversity data from 60 populations were used to assess the origin and frequency of introductions into the Midwest. Genetic variation and structure was compared …

"That Charm Of Remoteness": A Study Of Landscape Stability In Little Compton, Rhode Island, Katharine M. Johnson

Graduate Masters Theses

Little Compton, Rhode Island has long been considered a stable, isolated and rural location relative to surrounding towns and cities. A geophysical and archaeological examination in the front yards of the Wilbor house and Brownell farm was undertaken in order to gain a better understanding about how residents of the town maintained stable, rural lifeways during the period of industrialization and urbanization that characterized the rest of the state in the late 18th and early 19th centuries. The results from these examinations revealed that there was a distinct lack of features and landscaping changes in the archaeological record in the …

Population Ecology Of The Floodplain Herb Macbridea Caroliniana (Lamiaceae) With Investigations On The Species' Habitat, Breeding System And Genetic Diversity, Katherine Weeks

All Dissertations

The perennial herbaceous mint Macbridea caroliniana is known from 36 locations in discrete watersheds of the Carolinas and Georgia. It is one of relatively few conspicuously flowering herbs that occupy bottomland hardwood forests. The general project goal was to gain knowledge that is applicable to the species' conservation both at the Congaree National Park (CNP) where the largest known population of this species occurs and range-wide. Specific objectives were to (1) quantify the population size and describe the distribution of M. caroliniana within CNP, and determine the extent of co-occurrence with wild hogs and the non-native Murdannia keisak; (2) identify …

Effects Of Vegetation Structure On Fire Behavior And Wiregrass Seedling Establishment In Xeric Sandhills, Evelyn Wenk

All Theses

The xeric sandhills on Carolina Sandhills National Wildlife Refuge have a monospecific overstory of longleaf pine and an understory dominated by turkey oak and wiregrass. The understory vegetation is spatially heterogeneous within stands, with small patches dominated by either turkey oak or wiregrass, or lacking understory vegetation. I described the fuel complexes created by the variable vegetation structure, in terms of their chemical and physical properties, and used prescribed fire to test for differences in fire behavior among the vegetation types. In addition, I compared the effects of the vegetation structure and below-ground competition on the establishment of wiregrass.
Turkey …

Habitat Selection And Predation Risk In Larval Lampreys, Dustin M. Smith

Graduate Theses, Dissertations, and Problem Reports

This thesis examines habitat preference and the influence of habitat on predation of larvae (ammocoetes) of the least brook lamprey (Lampetra aepyptera). The thesis comprises three chapters: (1) an introduction and literature review on the general life history of lampreys and on studies related to ammocoetes and their habitat, (2) an experimental study of habitat preference in ammocoetes of the least brook lamprey, and (3) an experimental study of the relationship between habitat availability and predation risk in ammocoetes. For the first study, we quantified substrate selection in small (< 50 mm) and large (100-150 mm) ammocoetes of the least brook lamprey. In aquaria, ammocoetes were given a choice to burrow into six equally-available substrate types: small gravel (2.36-4.75 mm), coarse sand (0.5-1.4 mm), fine sand (0.125-0.5 mm), organic debris (approximately 70% decomposing leaves and stems, 15% silt, and 15% sand), an even mixture of silt, clay, and fine sand, and silt/clay (< 0.063 mm). Fine sand was selected with a significantly higher probability than any other substrate. In the second study, we experimentally examined the influence of habitat availability on predation risk of ammocoetes. Ammocoetes were placed in aquaria containing a predator species (yellow bullhead, Ameiurus natalis) and one of 3 substrates: fine sand (0.125-0.5 mm), coarse sand (0.5-1.4 mm), or silt/clay (<0.063 mm). Use of the three substrate types was based on a previous experiment where fine sand was determined to be the preferred benthic habitat of least brook lamprey. Based on 10 trials with each habitat type, survival of ammocoetes was highest in aquaria with fine sand (mean = 80%), and lower in those with coarse sand (mean = 58%) and silt/clay (mean = 4%). The results of both studies conducted indicate that populations of least brook lamprey ammocoetes may be limited by the availability of fine sand habitat. The first study indicated that least brook lamprey ammocoetes are habitat specialists, preferring substrates composed primarily of fine sand. The second study showed that the availability of fine sand habitat may influence the predation risk of ammocoetes, as ammocoete survival from predation was highest in fine sand, and lower in other substrates.

Life As A Sober Citizen : Aldo Leopold's Wildlife Ecology 118., Nancy Stearns Theiss

Electronic Theses and Dissertations

This historic case study addressed the issue of the lack of citizen action toward environmentally responsible behavior. Although there have been studies regarding components of environmental responsible behavior [ERB], there has been little focus on historic models of exemplary figures of ERB. This study examined one of the first conservation courses in the United States, Wildlife Ecology 118, taught by Aldo Leopold (1887-1948) for 13 years at the University of Wisconsin. Today, Aldo Leopold is recognized as an exemplary conservationist whose land ethic is cited as providing the ecological approach needed for understanding the complex issues of modern society. The …

Evaluating Dissolved Oxygen Regimes Along A Gradient Of Human Disturbance For Lotic Systems In West-Central Florida, Daniel G. Hammond

USF Tampa Graduate Theses and Dissertations

Land uses dominated by human activity can have a significant effect on ecological processes. In Florida, oxygen depletion is the most common impairment in lake, stream, and coastal water bodies. The continual growth and development in Florida, along with a conversion to more human intense land uses warrants study and discussion on impacts to dissolved oxygen regimes along a gradient of human disturbance. This research study is designed to identify observable trends in dissolved oxygen regimes along a gradient of increasing human intensity.

Twenty-six stations in the Tampa Bay area were selected to represent lotic systems in west-central Florida. Data …

Population Genetics Of Antarctic Seals, Caitlin Curtis

USF Tampa Graduate Theses and Dissertations

I developed and tested a protocol for determining the sex of individual pinnipeds using the sex-chromosome specific genes ZFX and ZFY. I screened a total of 368 seals (168 crabeater, Lobodon carcinophagus; 159 Weddell, Leptonychotes weddellii; and 41 Ross, Ommatophoca rossii) of known or unknown sex and compared the molecular sex to the sex assigned at the time of collection in the Ross and Amundsen seas, Antarctica. Discrepancies ranged from 0.0% - 6.7% among species. It is unclear, however, if mis-assignment of sex occurred in situ or in the laboratory. It also is possible, however, that …

Co-Occurrence With A Congeneric Species Predicts Life History And Morphological Diversification In The Mexican Livebearing Fish Poelicopsis Baenschi, Laura E. Scott

Theses and Dissertations

Understanding why some species coexist and others do not remains one of the fundamental challenges of ecology. While several lines of evidence suggest that closely related species are unlikely to occupy the same habitat because of competitive exclusion, there are many cases where closely related species do co-occur. Research comparing sympatric and allopatric populations of co-occurring species provides a framework to understand the role of phenotypic diversification in species coexistence. In this study I focus on the livebearing fish Poeciliopsis baenschi and ask if differences in phenotypic traits among populations can be explained by the presence or absence of the …

Environmental Regulation Of Carbon Isotope Discrimination And Internal Co2 Conductance In C3 Leaves, Christopher Bickford

Biology ETDs

Stable carbon isotopes are powerful tools for elucidating leaf- and ecosystem- level processes, and recent technological developments provide new opportunities to assess the isotopic flux during leaf gas exchange. In these studies I used a tunable diode laser spectroscope coupled to a infra-red gas analyzer to measure the isotopic composition of leaf gas exchange at high frequency in both field and greenhouse settings and assess environmental regulation of carbon isotope discrimination (Δ) and internal conductance of CO2 to sites of carboxylation (gi). I measured Δ and gi across diurnal and seasonal periods in field-grown Juniperus monosperma trees and used these …

Purple Martin, Progne Subis, In San Luis Obispo County Riparian Habitat: Presence, Persistence, Nesting, Brooding And Reproductive Success, Shannon Eileen Murphy

Biological Sciences

The State of California, as of 2002, identified the Purple Martin as a bird species of Special Concern (Airola et al., 2003). These migrants were historically found in a unique habitat in Central California; nesting in natural cavities of Western Sycamores within Riparian Habitats. I am proposing that Purple Martins still successfully nest and brood young in this unique habitat in San Luis Obispo County. The primary study site is in Atascadero where Highway 41 meets San Gabriel Road and San Gabriel Road crosses Atascadero creek. The secondary site is Highway 58 in Santa Margarita where the highway crosses the …

Discreet Dynamical Population Models : Higher Dimensional Pioneer-Climax Models, Yogesh Joshi

Dissertations

There are many population models in the literature for both continuous and discrete systems. This investigation begins with a general discrete model that subsumes almost all of the discrete population models currently in use. Some results related to the existence of fixed points are proved. Before launching into a mathematical analysis of the primary discrete dynamical model investigated in this dissertation, the basic elements of the model - pioneer and climax species - are described and discussed from an ecological as well as a dynamical systems perspective. An attempt is made to explain why the chosen hierarchical form of the …

Effects Of A Spatially And Temporally Predictable Chlorophyll Maximum On Bottlenose Dolphin Distribution In A South Carolina Estuary, Steven W. Thornton

Honors Theses

Numerous studies have focused on the complex relationship between phytoplankton and zooplankton in estuarine environments, but few have scrutinized the effects of this connection on organisms in higher trophic levels. This study examined chlorophyll a concentrations and zooplankton densities in North Inlet, South Carolina, a site where a stable chlorophyll a maximum has been documented to exist at low tide, to determine if they influenced the distribution of resident bottlenose dolphins (Tursiops truncatus). We hypothesized that patterns of estuarine circulation in the salt marsh serve to concentrate phytoplankton and zooplankton predictably in time and space, and that these patterns influence …

Effects Of Air Temperature And Lake Ice On Snowfall On The South Shore Of Lake Superior, Angela Pelkie Maki

University of New Orleans Theses and Dissertations

Lake Superior is a forcing factor for local weather systems, causing substantial amounts of lake effect snow in the winter (particularly on the south shore). This study assesses decreasing ice cover of Lake Superior and its effects upon synoptic weather factors. Data were collected from eleven National Weather Service (NWS) stations located on the south shore of the lake. Rainfall and snowfall amounts from December to May were regressed on percent ice coverage and average monthly temperatures from 1972-2002. Ice coverage and average monthly temperature had a negative relationship with snowfall and rainfall.