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- ETD (14)
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- Freshwater communities (2)
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- African elephant (1)
- African savanna elephant (1)
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Articles 1 - 27 of 27
Full-Text Articles in Ecology and Evolutionary Biology
Screening H3 Histone Acetylation In A Wild Bird, The House Sparrow (Passer Domesticus), Daniella Ray
Screening H3 Histone Acetylation In A Wild Bird, The House Sparrow (Passer Domesticus), Daniella Ray
Electronic Theses and Dissertations
Epigenetic mechanisms are increasingly understood to have major impacts across ecology. However, one molecular epigenetic mechanism, DNA methylation, currently dominates the literature. A second mechanism, histone modification, is likely important to ecologically relevant phenotypes and thus warrants investigation, especially because molecular interplay between methylation and histone acetylation can strongly affect gene expression. There are a limited number of histone acetylation studies on non-model organisms, yet those that exist show that it can impact gene expression and phenotypic plasticity. Wild birds provide an excellent system to investigate histone acetylation, as free-living individuals must rapidly adjust to environmental change. Here, we screen …
Mortality In Interspecific Hybrids Of Nasonia Vitripennis And Nasonia Giraulti, Bonnie Cobb
Mortality In Interspecific Hybrids Of Nasonia Vitripennis And Nasonia Giraulti, Bonnie Cobb
Electronic Theses and Dissertations
Nasonia is a parasitoid wasp genus that serves as an emerging model for studying speciation due to an incompatibility between nuclear and mitochondrial genomes between sister taxa. Short generation times, easy rearing in a lab setting, producing large amounts of progeny, and whole genome sequencing make Nasonia is an excellent candidate for studying incomplete reproductive isolation. Nasonia have five chromosomes and exhibit haplo-diploid sex determination in which fertilized eggs develop into diploid females and unfertilized eggs develop into haploid males. Recessive phenotypes are hidden in diploid females but are laid bare in haploid males as there is no interaction between …
Stop, Then Go! Rapid Acceleration Offsets The Costs Of Intermittent Locomotion When Turning In Florida Scrub Lizards, Cheyenne Walker
Stop, Then Go! Rapid Acceleration Offsets The Costs Of Intermittent Locomotion When Turning In Florida Scrub Lizards, Cheyenne Walker
Electronic Theses and Dissertations
Intermittent locomotion is a commonly used escape strategy with a wide array of potential benefits. Pausing may aid in locating a predator, crypsis, lowering energy costs, and avoiding obstacles. Turning may also benefit from intermittent locomotion by allowing an animal time to assess its surroundings; therefore, decreasing the chances of making a mistake and/or stumbling. Florida scrub lizards live in environments with a variety of obstacles such as turns. The goal of this study is to quantify the locomotor behavior and performance by lizards while navigating a 45° or 90° turn. Lizards were run along both a 45° and 90° …
Predation Threat In A Variable Landscape: Connecting Predation Risk To Nesting Success For The Seaside Sparrow (Ammospiza Maritima Macgilivraii), Corina D. Newsome
Predation Threat In A Variable Landscape: Connecting Predation Risk To Nesting Success For The Seaside Sparrow (Ammospiza Maritima Macgilivraii), Corina D. Newsome
Electronic Theses and Dissertations
Predation, the leading cause of nest-failure in birds, not only exists as a direct threat to nesting success, but may exacerbate other sources of nest mortality. Birds inhabiting Atlantic coastal marshes, such as Seaside Sparrows (Ammospiza maritima; hereafter SESP), are experiencing significant and rapid changes to their habitat, particularly sea level rise (SLR) and encroaching urbanization, that may affect the relative influence of nest predation on overall productivity. For SESPs, SLR presents an inherent threat to nest success in its potential to increase the frequency of nest flooding. In addition to this direct threat, the ability of SESPs …
Plasticity And The Impact Of Increasing Temperature On A Tropical Ectotherm, Adam A. Rosso
Plasticity And The Impact Of Increasing Temperature On A Tropical Ectotherm, Adam A. Rosso
Electronic Theses and Dissertations
Organisms may respond to climate change through behavior, genetic adaptation, and/or phenotypic plasticity. Tropical ectotherms are thought to be especially vulnerable to climate change because most have a narrow range of thermal tolerance while living close to their upper thermal tolerance limits. Additionally, many tropical species live in closed-canopy forests, which provide homogenous thermal landscapes that prevent behavioral compensation for stressfully warm temperatures. Finally, tropical ectotherms are thought to have decreased capacity for phenotypic plasticity because they have evolved in thermally stable environments. We tested gene expression patterns and phenotypic plasticity in the Panamanian slender anole by a) measuring changes …
Predator-Based Selection And The Impact Of Edge Sympatry On Components Of Coralsnake Mimicry, Lauren E. Wilson
Predator-Based Selection And The Impact Of Edge Sympatry On Components Of Coralsnake Mimicry, Lauren E. Wilson
Electronic Theses and Dissertations
Studying warning coloration and mimicry is an effective way to understand predator-driven selection and phenotypic diversity. The presence (sympatry) or absence (allopatry) of a toxic model plays a role in shaping mimetic phenotypes. However, the impact of edge sympatry and allopatry on predation of mimetic phenotypes is not well understood. We studied coralsnake mimicry to test how edge sympatry and allopatry affect predation on mimetic phenotypes. Specifically, we tested 1) if overall attack rates varied with edge sympatry of coralsnakes 2) which color patterns conferred a fitness advantage 3) which specific mimetic signal components are important in driving predatory attacks …
Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer
Impact Of Seasonal And Host-Related Factors On The Intestinal Microbiome And Cestode Community Of Sorex Cinereus And Sorex Monticola, Katelyn D. Cranmer
Electronic Theses and Dissertations
The intestinal microbiome of mammals plays a significant role in host health and response to environmental stimuli and can include both beneficial native bacteria as well as parasitic worms. In this study, I examined the intestinal cestode and bacterial communities of two closely related species of shrew, Sorex monticola and Sorex cinereus, over a six month period in 2016. Specimens were collected approximately every three weeks from May to October from the Sangre de Cristo Mountains in Cowles, New Mexico. A total of 79 shrews were prepared with the gastrointestinal tracts removed and flash-frozen in liquid nitrogen. An additional …
Inferring Food Web Structure To Identify Seasonal And Longitudinal Patterns In Ogeechee River Invertebrate Communities, Julien Marc Buchbinder
Inferring Food Web Structure To Identify Seasonal And Longitudinal Patterns In Ogeechee River Invertebrate Communities, Julien Marc Buchbinder
Electronic Theses and Dissertations
Understanding how the structure and function of aquatic communities vary across space and time is essential for proper management of freshwater ecosystems. Current management relies on rapid biomonitoring using metrics of community structure, but metrics that incorporate ecosystem processes and functions are only just beginning to see use in assessment and management. Food webs inferred from known species interactions have been proposed as a method of incorporating function into bioassessment without expending extra effort or sacrificing the cost-effectiveness of current monitoring schemes. To apply food webs in biomonitoring, it is first necessary to understand how communities and food webs vary …
Effects Of Climate Variability: A Long-Term Perspective On Leaf Litter Processing In The Ogeechee River, Jose A. Sanchez
Effects Of Climate Variability: A Long-Term Perspective On Leaf Litter Processing In The Ogeechee River, Jose A. Sanchez
Electronic Theses and Dissertations
The Intergovernmental Panel for Climate Change (IPCC) predicts a rise in temperatures and changes to precipitation patterns for the 21st century. These changes are expected to lead to a higher frequency of extreme events such as drought and floods which lead to the alteration of the hydrology, communities, and processes of freshwater ecosystems. Leaf litter decomposition in stream ecosystems is an important component of the energy and nutrient cycle representing a food source for aquatic organisms. This has made it a tool for assessing long term responses to disturbance due to changes in the assemblage of macroinvertebrates that …
Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon
Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon
Electronic Theses and Dissertations
Rivers and streams provide essential ecosystem services to the degree that the monitoring and maintenance of these systems becomes imperative. Biomonitoring provides managers and policymakers with the tools to make informed decisions, and macroinvertebrates are often the object of biomonitoring because they are ubiquitous in most systems and are known to be good indicators of water quality. However, methods for sampling macroinvertebrates in non-wadeable streams (i.e., large rivers) have not been standardized across states and regions and an established method for macroinvertebrate biomonitoring in large rivers of Georgia is not currently available. My study compared macroinvertebrates collected with three types …
Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott
Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott
Electronic Theses and Dissertations
Effective management of freshwater fishes requires a mechanistic understanding of the drivers of assemblage composition; in other words, what determines who is where and when. Stream fish assemblages are potentially influenced by environmental factors that act on multiple spatiotemporal scales, but the relative influence of these drivers may vary between geophysically distinct regions. This study sought to determine the patterns and drivers of fish taxonomic and functional assemblage composition in the coastal plain, a region possessing unique hydrologies, faunas, and physiochemical conditions. I addressed this goal using two complementary chapters, both of which utilized environmental and biotic data collected from …
Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr
Evolutionary Linkage Of Mimetic And Non-Mimetic Color Traits In A Coral Snake Mimicry Complex, John D. Curlis Jr
Electronic Theses and Dissertations
Color polymorphism in aposematic mimicry systems is a perplexing phenomenon for evolutionary biologists, as theoretically the benefits of converging on a model phenotype should constrain the evolution of phenotypic diversity in these systems (i.e., color polymorphism should not occur). Nevertheless, color polymorphism in mimicry systems is prevalent throughout many taxa. In some of these systems, the evolution of color polymorphism results in the existence of non-mimetic morphs, such as those that are cryptic. The case of ground snakes (Sonora semiannulata) is unique in that color polymorphism encompasses both mimetic and cryptic morphs, as well as individual mimetic and …
The Nutritional Value Of Fecal Sacs: Testing The Parental Nutrition Hypothesis, Amanda W. Burns
The Nutritional Value Of Fecal Sacs: Testing The Parental Nutrition Hypothesis, Amanda W. Burns
Electronic Theses and Dissertations
Nest sanitation is an important aspect of parental investment in birds with altricial nestlings. Passerine nestlings produce fecal matter that is encased in a mucous membrane for easy disposal. These fecal sacs are either removed from the nest and transported a distance away or they are ingested by the adult. A decline in fecal sac ingestion rates as nestlings age has been observed in several species. The parental nutrition hypothesis posits that this pattern can be attributed to increasing digestive efficiency as nestlings age. The parental nutrition hypothesis makes three predictions: fecal sac consumption rates should decrease as nestlings age, …
Epistasis In Predator-Prey Relationships, Iuliia Inozemtseva
Epistasis In Predator-Prey Relationships, Iuliia Inozemtseva
Electronic Theses and Dissertations
Epistasis is the interaction between two or more genes to control a single phenotype. We model epistasis of the prey in a two-locus two-allele problem in a basic predator- prey relationship. The resulting model allows us to examine both population sizes as well as genotypic and phenotypic frequencies. In the context of several numerical examples, we show that if epistasis results in an undesirable or desirable phenotype in the prey by making the particular genotype more or less susceptible to the predator or dangerous to the predator, elimination of undesirable phenotypes and then genotypes occurs.
Water Column Ammonium Concentration And Salinity Influence Nitrogen Uptake And Growth Of Spartina Alterniflora, Rachel Mactavish
Water Column Ammonium Concentration And Salinity Influence Nitrogen Uptake And Growth Of Spartina Alterniflora, Rachel Mactavish
Electronic Theses and Dissertations
Salt marsh macrophytes, such as Spartina alterniflora, play a critical role in uptake and transformation of inorganic nitrogen before it reaches coastal waters, thereby reducing the potential for eutrophication. Although nitrogen availability typically limits S. alterniflora growth, it may be possible to exceed the nitrogen uptake capacity of S. alterniflora. Increasing either nitrogen concentrations or salinity are key factors regulating S. alterniflora nitrogen uptake. Investigating the effects of nutrients and salinity on S. alterniflora is important given that increases in inorganic nitrogen supply to surface waters from agriculture and urbanization occur simultaneously with freshwater withdrawals that reduce flow and increase …
The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington
The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington
Electronic Theses and Dissertations
Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host’s population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1st chapter I determine the prevalence of Wolbachia pipentis infection in in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to …
Tactical Escape Behavior And Performance Of A Small Sceloporine Lizard In Two High Risk Habitats, Seth Parker
Tactical Escape Behavior And Performance Of A Small Sceloporine Lizard In Two High Risk Habitats, Seth Parker
Electronic Theses and Dissertations
The negotiation of uneven and complex terrain has implications for many small terrestrial vertebrates. Variation in the running surface due to obstacles like woody debris or vegetation can alter escape paths and running performance. Additionally, these microhabitat features can influence behavioral tactics in complex environments. The ability to negotiate physical barriers in dense environments likely influences survivorship through important ecological tasks, such as finding mates, foraging, and evading predators. The Florida scrub lizard (Sceloporus woodi) is a small, rare species endemic to two distinct and structurally complex environments in Florida, i.e. sand-pine scrub and longleaf pine-wiregrass sand-hills. The …
The Effects Of Herbicide On The Endangered Herb Baptisia Arachnifera And Preliminary Nutrient Survey Of Leaf Tissue And Soil, Ruth Ann C. Steinbrecher
The Effects Of Herbicide On The Endangered Herb Baptisia Arachnifera And Preliminary Nutrient Survey Of Leaf Tissue And Soil, Ruth Ann C. Steinbrecher
Electronic Theses and Dissertations
Baptisia arachnifera (Hairy Rattleweed) is an endangered herbaceous legume that only occurs in Wayne and Brantley Counties of Georgia, United States. Many of the remaining populations exist in areas now managed for timber. This study investigated the effects of Imazapyr, an herbicide commonly used in timber management, on health and vitality of B. arachnifera under both field and greenhouse conditions. This study also analyzed leaf and soil samples from six populations of B. arachnifera to determine the nutrient content of the leaves. A recensus of a B. arachnifera population was also conducted in a site without commercial timber management. In …
The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self
The Effects Of Locomotor Posture On Kinematics, Performance And Behavior During Obstacle Negotiation In Lizards, Jessica Self
Electronic Theses and Dissertations
The ability to efficiently move over uneven terrain is critical for most terrestrial animals. Bipedal running is common in lizard species, however the biological advantage of a bipedal running posture remains uncertain. I examined the hypothesis that a bipedal posture is advantageous when crossing obstacles. Particularly, I determined whether kinematic adjustments differ among four focal species with contrasting body forms and ecology. I also examined how sprint speed changed when crossing obstacles with a quadrupedal versus a bipedal posture. I quantified kinematics from high-speed video (300 frames/second) of lizards running down a 3m runway both with and without the presence …
Role Of Provisions And Season On Foraging And Female Dominance Behavior In Ring-Tailed Lemurs (Lemur Catta) On St. Catherine's Island, Timothy Moore
Role Of Provisions And Season On Foraging And Female Dominance Behavior In Ring-Tailed Lemurs (Lemur Catta) On St. Catherine's Island, Timothy Moore
Electronic Theses and Dissertations
Madagascar is undergoing habitat destruction and degradation that is threatening its unique species, including ring-tailed lemurs. Ring-tailed lemurs (Lemur catta) live in matriarchal groups composed of a dominant female, adult males, subadult males and females, and young. Due to their dominance, it has been suggested that female ringtailed lemurs have access to the highest quality resources and can monopolize food patches. Lemurs on St. Catherine's are free ranging and have unlimited access to natural food sources, but they are also provisioned with supplementary food to ensure a balanced diet. My study aimed to determine the impact of provisions on female …
Bird Use Of Cumberland Island's Freshwater Wetlands, Lisa Dlugolecki
Bird Use Of Cumberland Island's Freshwater Wetlands, Lisa Dlugolecki
Electronic Theses and Dissertations
Cumberland Island is the southernmost barrier island off the coast of Georgia. Its freshwater wetlands are an important, rare habitat to have on a barrier island surrounded by saltmarsh and ocean. Many species of birds require freshwater wetlands as feeding, roosting and nesting grounds. However, the freshwater wetlands on Cumberland Island have been impacted by humans for centuries causing birds to abandon their historic nesting ground. Known land use histories of Cumberland Island's freshwater wetlands were gathered to try and determine how the wetlands changed over time Wetlands were analyzed for presence of wetland-dependent birds and recorded. Thirty-six species of …
Predation Risk And Colony Structure In The Pea Aphid, Acyrthosiphon Pisum, Carl Nicolas Keiser
Predation Risk And Colony Structure In The Pea Aphid, Acyrthosiphon Pisum, Carl Nicolas Keiser
Electronic Theses and Dissertations
Many organisms live in transient or permanent aggregations to reduce individual predation risk. Hamilton's "Selfish Herd" theory states that an individual should assume a central position within a group to decrease individual predation risk relative to that of its neighbors (i.e., individuals should be selfish). This theory, however, cannot predict the spatial distribution of individuals within clonal aggregations, that is, when individuals are genetically identical (the "evolutionary self"). As aphids (small, herbivorous insects) are parthenogenetic, emit alarm signals, and have high levels of phenotypic plasticity to cope with environmental stressors like predation risk, they are a model organism for investigating …
Effects Of Habitat Quality On Reproduction In Two Georgia Populations Of Gopherus Polyphemus, Jaqueline W. Entz
Effects Of Habitat Quality On Reproduction In Two Georgia Populations Of Gopherus Polyphemus, Jaqueline W. Entz
Electronic Theses and Dissertations
Author's Abstract: The purpose of this study was to examine differences in maternal investment by examining variation in the habitat structure and reproductive parameters for two populations of Gopherus polyphemus in Southeast GA. Both habitat structure and reproductive parameters for these populations are known from a previous study, thus this study expands upon the previous one and addresses four main questions. (1) Has habitat quality changed in the past ten years within and between population sites? (2) Could a change of habitat have affected female morphology or female reproductive parameters within or between populations? (3) Is female body size shaping …
Tidal Influences On Bacterial And Phytoplankton Abundances And The Resulting Effects On Patterns Of Dissolved Oxygen In The Skidaway River Estuary, Casey Colleen Brazell
Tidal Influences On Bacterial And Phytoplankton Abundances And The Resulting Effects On Patterns Of Dissolved Oxygen In The Skidaway River Estuary, Casey Colleen Brazell
Electronic Theses and Dissertations
Two studies were conducted to investigate the physical and biological processes contributing to the dissolved oxygen (DO) availability in the Skidaway River Estuary (SRE), Savannah, GA during the summer of 2005. A temporal study looked at changes in DO concentrations, Chlorophyll a concentrations, bacterial abundance, water depth, and salinity, every hour, for 26 hours, over both a neap and a spring tide. A spatial study looked at changes in the above variables at 5 sites along the SRE while following the tide inland during a neap high and low tide, and a spring high and low tide. DO concentrations varied …
Host And Seasonal Effects On The Infection Dynamics Of Skrjabinoptera Phrynosoma (Ortlepp) Schulz, 1927, A Parasitic Nematode Of Horned Lizards, Kathryn Claire Hilsinger
Host And Seasonal Effects On The Infection Dynamics Of Skrjabinoptera Phrynosoma (Ortlepp) Schulz, 1927, A Parasitic Nematode Of Horned Lizards, Kathryn Claire Hilsinger
Electronic Theses and Dissertations
Author's Abstract: Skrjabinoptera phrynosoma (Ortlepp) Schulz, 1927 is a common parasitic nematode of horned lizards. The life cycle of S. phrynosoma was described by Lee in 1957, but has received little attention since. The present study addressed effect of season as well as host characteristics on the infection dynamics in lizard hosts. In the Alvord Basin in southeastern Oregon, S. phrynosoma were collected from Phrynosoma platyrhinos Gerard 1852 horned lizards via stomach flushes, cloaca flushes and fecal pellet collections. Parasite load variables (number of nematodes per host, length of those nematodes, and total worm burden (ΣL)) were analyzed within three …
Waterhole Dynamics And Chemical Signals Of African Elephants ( Loxodonta Africana ), Stacie Marie Castelda
Waterhole Dynamics And Chemical Signals Of African Elephants ( Loxodonta Africana ), Stacie Marie Castelda
Electronic Theses and Dissertations
The distribution of mammals in a savanna environment is influenced by abiotic and biotic factors. The African savanna experiences distinct wet and dry seasons. Species become spatially restricted around water resources during the dry season, resulting in increased intraspecies and interspecies resource-based aggregation. A dominate species, such as the African elephant (Loxodonta africana), may influence this aggregation. I examined the influence of wet and dry seasons and ambient temperature on the use of a waterhole by elephants as well as the co-occurrence of elephants and other mammals at the waterhole. Biodiversity scans (October 2004-June 2007) and were performed at a …
The Winter Ecology Of The Piping Plover (Charadrius Melodus) In Coastal Georgia, Brandon Lennon Noel
The Winter Ecology Of The Piping Plover (Charadrius Melodus) In Coastal Georgia, Brandon Lennon Noel
Electronic Theses and Dissertations
Author's abstract: The Piping Plover (Charadrius melodus) is a federally listed species with three distinct breeding populations, including Great Plains (threatened), Great Lakes (endangered), and Atlantic Coast (threatened), all of which winter along the Atlnatic and Gulf coasts of the United States. I studied the winter ecology of the Piping Plovers on Little St. Simons Island (LSSI), Georgia, from 2003-2006, with emphasis on the conservation significance of this site for the endangered Great Lakes population. During 2003-2004 and 2004-2005, LSSI supported up to 100 Piping Plovers during peak migration, and approximately 40 birds wintered at this site. All populations had …