Ecology and Evolutionary Biology Commons^™

The Effect Of Self-Recognition In The Competition Between Genets Of Solidago Altissima, Charles Jaques

Masters Theses

Competition is a major driving force in the abundance, distribution, and diversity within any biological system. Plants are more likely to suffer reductions in fitness as a consequence of competition, as they typically occur in dense communities. Individuals within these populations must respond to both inter- and intraspecific competition. Recent studies suggest that the ability to distinguish kin from non-kin may play an integral role in the success of individuals within different plant populations and communities. However, a less known interaction is that between individual clones within a genet as they grow, spread, and begin to interact with nearby rival …

Impact Of Giant Miscanthus (Miscanthus X Giganteus) Cultivation On Midwestern Farmland Birds, Matthew Craffey

Masters Theses

Giant Miscanthus (Miscanthus x giganteus) is a promising bioenergy feedstock, newly introduced to North America. However, the qualities that make Giant Miscanthus an attractive bioenergy feedstock may pose challenges to local wildlife. To assess the impacts of Giant Miscanthus on Midwestern farmland birds, I conducted point count and vegetation surveys at three sites in east-central Illinois where Giant Miscanthus was being cultivated. I used occupancy modeling to assess the relative influence of Giant Miscanthus on five species relative to other habitat and landscape characteristics. Dickcissel (Spiza Americana), Eastern Meadowlark (Sturnella magna), and Red-Winged Blackbird …

Evaluation And Demographic Response Of The Shovelnose Sturgeon Commercial Caviar Fishery In The Wabash River, Jessica L. Thornton

Masters Theses

Shovelnose sturgeon (Scaphirhynchus platorynchus Rafinesque) are considered one of the last commercially viable options for sturgeon roe harvest. Due to the collapse of several marine sturgeon fisheries and the Similarity of Appearances provision which protect shovelnose sturgeon in only a part of their range, the caviar fishery in the Wabash River remains an important point of supply for this lucrative natural resource. In this thesis, I presented an evaluation of the shovelnose sturgeon commercial caviar fishery in the Wabash River. More specifically, I described the demographic response of this population to continued exploitation over a 10-year period. Additionally, I …

Impact Of Temperature Increase On Freshwater Fish Species: Energetics And Muscle Mechanics Of Two Centrarchids, Israt Jahan

Masters Theses

Fishes have evolved physiologically to live within a specific range of environmental variation and existence outside of that range can be stressful or fatal. These ranges can coincide for fishes that evolved in similar habitats. This study investigates physiological processes limiting thermal tolerance, specifically how changes in water temperature affect the swimming energetics and muscle mechanics in largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus). I focused on the impact of temperature change at the muscle level in these two species and the capacity to adapt to rapid changes in the environment. Fish were housed at …

Potential For Climate Induced Methane Hydrate Dissociation, Graham Macwilliams

Pomona Senior Theses

Methane hydrates are frozen deposits of methane and water found in high pressure or low temperature sediments. When these deposits destabilize, large quantities of methane can be emitted into the atmosphere. This is significant to climate change because methane has 25 times more greenhouse gas potential than Carbon Dioxide. Worldwide, it is estimated there are between 2500 and 10000 gigatons of methane stored in hydrate deposits. This represents more carbon than all fossil fuels on Earth. It is estimated that between 200 and 2000 gigatons of methane are stored in hydrates in Arctic waters acutely vulnerable to greenhouse warming. Over …

A Review Of Heat Stress Policies In The Context Of Climate Change And Its Impacts On Outdoor Workers: Evidence From Zimbabwe, Bigboy Ngwenya, Jacques Oosthuizen, Martyn Cross, Kwasi Frimpong, Cynthia N. Chaibva

Research outputs 2014 to 2021

Record-breaking summer heat events are increasing in frequency in Zimbabwe and 2016 was a particularly hot year with the country experiencing its worst heat wave event in decades. Currently, Zimbabwe has no coordinated public health response to deal with heat wave events and no specific data on heat-related morbidity and mortality. The country has no legislation for protecting workers against environmental heat exposure, particularly those most vulnerable who are employed in the informal sector. These workers are also at risk due to their outdoor work environments. The article outlines the state of climate and heat stresses in Zimbabwe, as benchmarked …

Arthropod Diets In Chihuahuan Desert Snakes, Victor Manuel Parga

Open Access Theses & Dissertations

Over the past century, studies in herpetology regarding snake diets have been commonly focused on those species that feed or specialize in vertebrate prey items. For those that feed primarily on invertebrates however, little work has been done in determining diet specializations and comparing diets within a community of species. This Thesis focuses on small species of snakes that feed primarily on arthropods in a Chihuahuan Desert community, and will investigate if these are diet generalists or specialists. To this end, stomach contents were examined from preserved specimens of the following species: Rena humilis and Rena dissecta (Leptotyphlopidae), Gyalopion canum …

Estimating Exploitation Rates In The Alabama Red Snapper Fishery Using A High-Reward Tag–Recapture Approach, Dana K. Sackett, Mattgew Catalano, J. Marcus Drymon, Sean P. Powers, Mark Albins

University Faculty and Staff Publications

Accurate estimates of exploitation are essential to managing an exploited fishery. However, these estimates are often dependent on the area and vulnerable sizes of fish considered in a study. High-reward tagging studies offer a simple and direct approach to estimating exploitation rates at these various scales and in examining how model parameters impact exploitation rate estimates. These methods can ultimately provide a better understanding of the spatial dynamics of exploitation at smaller local and regional scales within a fishery—a measure often needed for more site-attached species, such as the Red Snapper Lutjanus campechanus. We used this approach to tag 724 …

Effects Of Increasing Deciduous Shrub Litter On Ecosystem Functioning In Alpine Tundra, Alejandro Emmanuel Benhumea

Open Access Theses & Dissertations

Rising temperatures due to global warming have resulted in rapid environmental changes in northern environments, resulting in an increase in deciduous shrub growth which has the potential to alter soil ecosystem properties and processes. In order to address some potential mechanisms by which shrubs alter ecosystem properties and processes, we designed an experiment which separated the effects of physical shrub presence and the effects of litter quantity in a fully factorial experiment on a north facing alpine plateau in the southwest Yukon, Canada. Specifically, we asked the following questions: What are effects of shrub litter, independent of shrub presence, on …

Hidden Diversity In Aquatic Habitats: Lessons From Cryptic Species In Microscopic Invertebrates (Rotifera), Azar Kordbacheh

Open Access Theses & Dissertations

Speciation is a continuous and adaptive process by which lineages are diverged into multiple groups, and species are the product of this process. Taxonomy is the study of relationship between organisms, classifying and naming them, and one of the taxonomical challenges is delimiting species boundaries. Species delimitation can be controversial because biologists do not agree on species concepts and approaches for defining species boundaries. One of the well-known species concepts is the Biological Species Concept that requires studying reproductive barriers among populations. Investigating strength of reproductive isolation among populations is not always practical in the wild. Therefore, many biologists have …

Chironomidae (Diptera) Community Structure In Lakes Of Contrasting Morphometry, Landscape Position, And Water Chemistry, Conrad Stanley Zack

Master's Theses

Chironomidae (Diptera) surface-floating pupal exuviae were collected monthly during the ice-free season in 2010-2011 from six lakes in the North Temperate Lakes Long-Term Ecological Research site in northern Wisconsin. The goal of this study was to determine whether chironomid community structure reflected differences in lake morphometry (i.e., depth, area, shoreline development, etc.), water chemistry, and/or landscape position (i.e., elevation). Forty-six genera were identified from four subfamilies: Chironominae (57%), Orthocladiinae (28%), Tanypodinae (11%), and Diamesinae (4%). Tanytarsus, Ablabesmyia, and Psectrocladius were found in all six study lakes; whereas certain genera, such as Omisus, Protanypus, and Epoicocladius were each observed in only …

The Role Of Vegetation-Topographic Interactions In A Barrier Island System: Island Migration In A Changing Climate, Benjamin Nettleton

Theses and Dissertations

Islands have been characterized based on vegetation and topography as exhibiting different disturbance regimes - reinforcing or resisting. This study had two objectives: quantify barrier island upland migration and vegetation cover change over 32 years (1984-2016), and assess tolerance of two prevalent dune grass species, A. breviligulata, and S. patens to sand burial. Using Landsat imagery from the Virginia Coast Reserve, islands were categorized within the disturbance resistance/reinforcing framework based on dune elevation. Resistant areas were associated with woody cover and low marsh to upland migration while reinforcing areas had low vegetation cover and high rates of migration. System-wide, …

Evolution Belief Trends, Jamie Jensen

ScholarsArchive Data

This is the essay code frequencies along with the raw survey data for both Cohort 1 and Cohort 2 for the following paper:

Bradshaw, WS, Phillips, AJ, Bybee, SM, Gill, RA, Peck, SL, Jensen, JL. 2018. A longitudinal study of attitudes toward evolution among Mormon undergraduates. PLOSONE.

Omnivore Density Affects Community Structure Through Multiple Trophic Cascades, Donald J. Benkendorf

Murray State Theses and Dissertations

Omnivores can dampen trophic cascades by feeding at multiple trophic levels, yet few studies have evaluated how intraspecific variation influences the effect of omnivores on community structure. The Speckled Dace (Rhinichthys osculus) is an omnivorous cyprinid that consumes algae and invertebrates and is abundant throughout the western United States. I sought to identify the effects of size and size structure on top-down control by dace and learn how these effects scaled with density. Dace were manipulated in a mesocosm experiment and resulting changes in invertebrate and algal communities and measures of ecosystem function were monitored. Omnivores affected experimental …

Relationships Between Factors Influencing Biofilm Formation And Pathogen Retention In Complex Rhizosphere Microbial Communities, Aaron Coristine

Theses and Dissertations (Comprehensive)

Riparian wetlands are unique habitats facilitating all forms of life. The riverbanks of these environments provide ideal conditions for bacteria, plants, and higher organisms. Of particular interest to this research was the variation in microbial community structure at high, intermediate and poor water quality impacted areas. Assessing the capabilities of plants to retain microbial pathogens was identified. Root systems and corresponding soil are ideal locations for bacterial deposition, resulting in attachment at these areas. Biofilm production in these regions is important for long-term establishment, leading to persistence and potential naturalization. Opportunistic pathogens originating from mammalian fecal matter are introduced into …

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 …

Near-Surface Permafrost Ground Ice Characteristics And Ecological And Physical Drivers Of Transient Layer Ice Content In Discontinuous Permafrost, Jason Paul

Theses and Dissertations (Comprehensive)

Accelerated climate warming in northern regions is causing permafrost degradation, leading to the reduction of the areal extent of permafrost. Permafrost is the foundation for many northern ecosystems and communities, so its thaw can have important ecological and societal consequences. Thaw of ice-rich permafrost can cause subsidence of the ground surface proportional to excess ice content. Terrain settlement can cause ponding or damage to infrastructure. Following a surface disturbance that removes much of the vegetation cover, a shift in the ground thermal regime can cause an increase in active layer thickness and rapid thaw of the top portion of permafrost. …

Predictors Of Fish Assemblage Structure And Dynamics In Atlantic Coastal Plain Streams, Rebecca Scott

College of Graduate Studies: Theses & 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 …

Comparison Of Three Benthic Macroinvertebrate Passive Sampling Devices For Non-Wadeable Streams, Kelsey A. Laymon

College of Graduate Studies: Theses & 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 …

Foraging Ecology Of A Winter Bird Community In Southeastern Georgia, Rachel E. Mowbray

College of Graduate Studies: Theses & Dissertations

Classical views on community structure emphasized deterministic processes and the importance of competition in shaping communities. However, the processes responsible for shaping avian communities remain controversial. Attempts to understand distributions and abundances of species are complicated by the fact that birds are highly mobile. Many species migrate biannually between summer breeding grounds and wintering grounds. The goal of this study was to test four hypotheses that attempt to explain how migratory species integrate into resident assemblages of birds (Empty-Niche Hypothesis, Competitive-Exclusion Hypothesis, Niche-Partitioning Hypothesis, and Generalist-Migrant Hypothesis). I collected data on birds foraging during the winter of 2017-2018 in Magnolia …

Researchers, Not Dogs, Lack Control In An Experiment On Jealousy, Jennifer Vonk

Animal Sentience

Cook and colleagues (2018) have developed a clever method to measure fMRI in awake dogs in response to a number of interesting stimuli. As a result, they are able to determine neural correlates of observable behavior. They report that dogs may experience something akin to jealousy because they show greater amygdala activation in response to food being given to a fake dog versus food being placed in a bucket. However, several critical controls are missing which prevent the authors from being able to speak of jealousy.

Finding The Green-Eyed Monster In The Brain Of A Dog, Peter Singer

Animal Sentience

That dogs show behavior suggestive of jealousy has long been known and has been demonstrated under controlled conditions. Cook et al. have now shown arousal in the amygdala when dogs see a caregiver feeding another dog. This finding has ethical significance in two respects. First, the consideration shown by the investigators for the welfare of their experimental subjects sets an example for other researchers using animals. Second, the greater understanding of the emotional lives of animals should lead to more concern for their needs.

Jealousy, Competition, Or A Contextual Cue For Reward?, Thomas R. Zentall

Animal Sentience

Emotions are difficult to assess, even in humans. The attribution of jealousy in an animal like a dog is especially difficult because performance of a particular behavior in the context of another animal receiving a reward may not be easily distinguishable from intra-species competition or simply a response to a contextual cue for the availability of reward. The authors provide distinguishing evidence in the form of fMRI data to show that in the presence of a “fake” dog being fed, there is bilateral activation in the amygdala, an area associated with anxiety, anger, fear, and even jealousy in humans.

What Can The Social Emotions Of Dogs Teach Us About Human Emotions?, Dean Mobbs

Animal Sentience

It has long been believed that social emotions such as guilt and jealousy are only expressed in humans. In the case of jealousy, its adaptive value has been linked to the prevention of sexual infidelity or fairness. So why would dogs feel jealousy? I suggest that understanding how social emotions have been bred into dogs can help us understand our own emotions, including their functionality — and potentially their mechanisms.

Can Neuroimaging In Dogs Have Practical Implications?, Tiffani J. Howell

Animal Sentience

Jealousy, or at least aggression, can be observed in dogs using neuroimaging techniques, but this response attenuates quickly following repeated exposure to the aggression-inducing stimulus. This may have a practical application. Early socialisation as a puppy, and habituation as an adult dog, could help prevent undesirable behaviours such as predatory behaviour. It is unclear whether these processes are the same, and affected only by the dog’s age. Neuroimaging could help us understand whether the same neurological processes underlie socialisation and habituation, and whether self-rewarding behaviours such as predatory behaviour could be stopped using socialisation/habituation techniques.

Lessons From Behaviour For Brain Imaging, Carolyn J. Walsh

Animal Sentience

Integrating physiological and behavioural arousal with social context is fundamental to understanding affect in dogs. Cook et al. (2018) have made a worthy start towards illuminating the neural basis of dog affect underlying resource loss. However, their study depends on retrospective behaviour reports versus direct testing, and an interpretation of differential neural activation that is based on too few dogs. Research groups conducting canine brain-imaging work might: (1) consider collaborative approaches to augment sample sizes and replicability, and (2) take a recent lesson from dog behavioural research regarding a more cautious approach to applying functional labels to physiological and/or behavioural …

On Jealousy, Envy, Sex Differences And Temperament In Humans And Dogs, Eddie Harmon-Jones, Sylvia K. Harmon-Jones

Animal Sentience

Cook, Prichard, Spivak, and Berns (2018) find that dogs’ levels of trait aggression are positively correlated with their amygdala activation when observing their caregivers giving a food to a fake dog. The authors conclude that this may provide neural evidence in dogs for the experience of jealousy, an emotion that some psychologists consider to be unique to humans. Here we explain the difference between the emotions of jealousy and envy, suggesting some ideas for future experiments that may help disentangle the experience of jealousy from that of envy in dogs. We also propose ideas for future research that may yield …

Inferring Emotion From Amygdala Activation Alone Is Problematic, Thomas F. Denson

Animal Sentience

Cook et al. investigated neural responses in domestic dogs in an experiment designed to elicit jealousy. Relative to a control condition, watching the dogs’ caregivers feed a fake dog activated the amygdala bilaterally. Dogs rated higher in dog-directed aggressiveness showed larger initial amygdala activation. Amygdala activity in this context is insufficient evidence to infer that the dogs experienced jealousy or even negative affect. The experimental design does not provide an adequate level of control to infer the presence of jealousy.

Jealousy? Or Just Hostility Toward Other Dogs? The Risks Of Jumping To Conclusions, James A. Serpell

Animal Sentience

Cook et al. (2018) provide a fascinating demonstration of amygdala activation in dogs when they witnessed their owners giving food to another (fake) dog, but not when they placed food in a bucket. Dogs’ neurological responses were positively correlated with their reported levels of ‘dog-directed aggression’ as measured by the C-BARQ, and dogs with initially strong amygdala responses habituated on subsequent trials. The authors interpret their findings as possible evidence for an emotion akin to jealousy in dogs. However, alternate interpretations involving either dog aggression/fear or emotional responses to food seem more plausible and avoid the welfare risks associated with …

What Would We Like To Know By Imaging The Brains Of Dogs?, Ralph Adolphs

Animal Sentience

Using fMRI to study emotions in animals is important, fascinating, and fraught with methodological and conceptual problems. Cook et al. are doing it, and there is no question that they and others will be doing it better and better as time goes on. Where will this lead us? What could fMRI in principle tell us about the minds of nonhuman animals?