Ecology and Evolutionary Biology Commons^™

Spatiotemporal Dynamics Of Disease: Social And Environmental Drivers Of Movement, Connectivity, And Disease Transmission In Bighorn Sheep, Lauren E. Ricci

All Graduate Theses and Dissertations, Fall 2023 to Present

Movement is a fundamental component of animal ecology. Animals move in order to access resources and avoid risk. Movement decisions aggregated across time determine how individuals use space, contact dynamics between individuals within a population, and connectivity across a species range. These patterns that emerge from movement decisions have downstream implications for many ecological processes and a mechanistic understanding of movement can help answer broader questions about ecology.

Disease dynamics are intrinsically tied to movement. Understanding the mechanisms that drive movement can elucidate how disease will spread and impact host populations. In this vein, I employed a suite of movement …

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

Analysis Of Seasonal Changes In Thermal Stress Resilience And Innate Immunity In The Temperate Coral, Astrangia Poculata, From Future Climate Impacts, Tyler Eugene Harman

Masters Theses

Over the years, global warming has had a devastating effect on coral reef ecosystems. Anthropogenic influences have caused significant increases in greenhouse gases, with a subsequent increase in solar radiation held within Earth’s atmosphere leading to increasing global temperatures. The increasing temperatures from concurrent increases in greenhouse gases impact fragile marine ecosystems such as coral reefs, which require particular environmental parameters such as temperature in order to survive and maintain a diverse ecosystem in which many marine species rely on. These increases in temperature exacerbate phenomena such as bleaching events and coral disease, drastically impacting coral on a global scale …

Effects Of Infection Of The Protist Parasite, Dermomycoides Sp., In Dusky Gopher Frog Tadpoles, Jaime Smith

Master's Theses

Infections of the protist parasite, Dermomycoides sp. are thought to have caused several years of low recruitment in the dusky gopher frog (Rana sevosa) populations. I evaluated the effects of density of the infective zoospores, host developmental stage, and tadpoles' ability to acquire resistance to Dermomycoides sp. on dusky gopher frog tadpoles. Tadpoles were exposed to zoospore densities of 0, 250, 500, and 750 zoospores/µL at Gosner stage 25, and we found no significant differences among treatments in tadpole mortality. In evaluating susceptibility by development stage, I exposed R. sevosa to 50 zoospores/µL as eggs, embryos, hatchlings, and …

Behavioral Thermoregulation And Thermal Mismatches Influence Disease Dynamics In Amphibians, Erin Louise Sauer

USF Tampa Graduate Theses and Dissertations

Amphibians are currently the most threatened vertebra taxa on the planet. Hundreds of species are thought to have gone extinct while thousands more have been listed as threatened or endangered over the past few decades. Habitat loss, invasive species, climate change, and disease are all thought to have partially contributed to these declines. Two pathogens in particular, infectious viruses in the genus Ranavirus (simply referred to as ranavirus) and the fungus Batrachochytrium dendrobatidis (Bd), have been associated with global mass mortality events of amphibians. Virulent pathogens such as these tend to impose strong selective pressures on their hosts driving the …

Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen

HCNSO Student Theses and Dissertations

Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied …

Defending Wild Dogs: Population Dynamics And Disease In Endangered African Wild Dogs, Elizabeth Claire Arredondo

Graduate Theses and Dissertations

African wild dogs (Lycaon pictus) are endangered carnivores whose population is decreasing from habitat loss and fragmentation, interspecific competition, and disease. Survival rates are especially low in Kruger National Park (KNP), though it is unclear why. I estimated the abundance in KNP and survival rates over different time spans, six years and nine months, using public photographic survey data. In 2015, there were 298 (SE=12.1) individuals. Using a mark-recapture analysis in program R, I found that the survival rate between 2009-2015 was only 3.2%, and within the 9-month survey period (September 2014 – June 2015), monthly survival rates for the …

Haemosporidian Parasites And Host Immune Function Of Galapagos Avifauna, Maricruz Jaramillo

Dissertations

The large number of emergent infectious diseases witnessed in the past few decades has increased interest in the ecology and distribution of potentially threatening pathogens worldwide. Island species are often considered more vulnerable to parasites due to their impoverished parasite communities, long isolation from disease and low genetic diversity. Avian surveys done by our group on the Galapagos Islands have found various pathogens infecting their endemic avifauna, including haemosporidian parasites of the genera Plasmodium and Haemoproteus. My research seeks to understand the relationships between two haemosporidian parasites (blood parasites) and their multiple bird hosts in Galapagos and to explore …

Trophic Interactions And Niche Partitioning Within A Post-White-Nose Syndrome Temperate Bat Community, Macy Kailing

Murray State Theses and Dissertations

The decline of cave-dwelling bats since the introduction of white-nose syndrome (WNS) to North America changed the way communities interact. Disease-mediated competition at the community level can influence the ability of imperiled species to recover because of competitive exclusion. In western Kentucky, tri-colored bats, Perimyotis subflavus, which are susceptible to WNS severely declined following WNS occurrence. During that same period, evening bats, Nycticeius humeralis, which are not susceptible to WNS increased markedly. To investigate the influence of WNS on community structure, the diets of sympatric tri-colored and evening bats were assessed. Guano was collected from evening (n=37) and …

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …

The Effect Of "Casitas" On Lobster Biology And Fishery Sustainability In The Bahamas, Lester George Gittens

Biological Sciences Theses & Dissertations

“Casitas” (artificial table-like structures) are a commercial fishing gear used to harvest Caribbean spiny lobster (Panulirus argus) in the Caribbean and in The Bahamas, where lobster is the most valuable fishery. Yet, casitas are largely unregulated in The Bahamas and they may threaten fishery sustainability through alteration of lobster growth, disease, or mortality rates and due to insufficient information concerning their number and location. Focusing on the lobster fishery in The Bahamas, my objectives were to: (1) investigate the mortality, growth, and susceptibility to disease of lobsters collected in casitas compared to wooden traps and those living in …

Climate Change Drives Outbreaks Of Emerging Infectious Disease And Phenological Shifts, Jeremy Cohen

USF Tampa Graduate Theses and Dissertations

Climate change is expected to impact species by altering infectious disease outcomes, modifying community composition, and causing species to shift their phenology, body sizes and range distributions. However, the outcomes of these impacts are often controversial; for example, scientists have debated whether climate change will exacerbate emerging infectious disease and which species are at greatest risk to advance their phenology. There reason for these controversies may be that climate change is impacting diverse processes across a wide range of ecological scales, as the interplay between fine-scale processes and broad-scale dynamics can often cause unpredictable changes to the biosphere. Therefore, it …

Bats And Disease: Behavioral And Community Responses Of Southern Bat Populations During The White-Nose Syndrome Epizootic, Riley Fehr Bernard

Doctoral Dissertations

This dissertation investigates regional differences in the behavior and activity of bats in eastern North America during the white-nose syndrome epizootic, specifically in the understudied region of the Southeastern United States. An introductory section provides a brief review of the history of white-nose syndrome, an emerging infectious disease in bats, and its introduction into North America. Chapter one provides the first documented evidence of bat activity outside of hibernacula throughout winter. The research presented in chapter two attempts to explain the variation in load and prevalence of P. destructans among species, sites and between years. Finally, chapter three examines the …

Understanding Amphibian Decline: The Role Of Pesticides And The Pathogenic Chytrid Fungus On Amphibians And Aquatic Communities, Taegan A. Mcmahon

USF Tampa Graduate Theses and Dissertations

Amphibians are the most threatened taxon on the planet. Declines have been associated with over-exploitation, habitat loss, pollution, and pathogenic diseases, but of these factors, pollution and disease have been relatively under-studied. Here, I investigated: 1) the impacts of commonly used pesticides on aquatic communities, 2) the effect of these pesticides on amphibian susceptibility to the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd), and 3) whether there are non-amphibian hosts of Bd and 4) how to best quantify the survival of Bd through ontogeny of the host.

In my first research chapter, I quantified the effects of environmentally relevant concentrations of …

The Importance Of Disease And Behavior In Mammalian Ecology And Behavior, Christopher R. Collins

Legacy Theses & Dissertations (2009 - 2024)

Causes of mortality reflect the evolutionary forces shaping the physiology and behavior of species. To evaluate the relative importance of these in North American Mammals I compared published data from 69 populations across 27 species. Of the known causes, humans are the main cause of mortality (51.8%), followed by natural causes (48.5%), with predation being the largest natural cause. Populations in remote areas experienced higher hunting mortality, and those closer to human populations suffered increased vehicle collision. Predation mortality was negatively correlated with body mass.

Disease And Habitat Change As Factors Associated With Mourning Dove Population Decline, William D. Ostrand

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The western mourning dove (Zenaida macroura) population has been declining since 1966. Data collected in 1951-52, in Fillmore, Utah, provided us a baseline for comparison with our study in the same area. Our approach was to determine whether a local population decline had occurred since the original data were collected, assess if trichomoniasis has impacted the local population, determine if changes in habitat structure affect foraging site selection, quantify changes in habitat, identify which habitats doves preferred, ascertain whether doves had responded to habitat change by changing food habits, and assess if changes in habitat were responsible in …

The Effects Of Disease, Prey Fluctuation, And Clear-Cutting On American Marten In Newfoundland, Canada, Richard J. Fredrickson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Individual variation in survival and behavior of American marten (Martes americana) was studied in relation to disease, prey fluctuation, and clear-cutting from 10 January 1986 through 20 August 1987 in Newfoundland, Canada. Thirty-seven of forty marten captured on the study area were telemetered and monitored for part or all of the study.

Marten mortality was concentrated in two intervals, fall 1986 and late winter 1987. Mortality during fall 1986 was attributable to encephalitis, while marten deaths during late winter 1987 resulted from predation and starvation attributable to the prey decline. Nonsuppurative encephalitis was first detected 7 October 1986; …