Doctor of Philosophy, Case Western Reserve University, 2024, Psychology

In biological and artificial intelligence research, random search has been found to be an effective strategy for exploring unfamiliar environments. This search often can be described as a Levy walk: a superdiffusive distribution of many short “steps” (movements without pause or change of direction) with rarer long steps across longer distances. Levy walks have been observed in the behavior of many species at various scales, being relevant to the movement and search behavior of organisms such as microbes, worms, and primates. Humans also exhibit Levy walks, such as when learning locations of resources to exploit both in the moment and the future. When on established trails to known resources, humans have been observed to deviate from and return to these trails for unclear reasons. While the scale-less nature of Levy walks is known, application of Levy walks at multiple scales in individual organisms has not been well studied. What remains to be asked is, does the random search strategy used when looking for the area where resources are located compare to the search strategy employed within a patch of resources for the actual goal items? Thus, this study had two primary areas of investigation. The first is investigating whether human search for patches of resources and search within those patches can both be classified as Levy walks. This was accomplished via the use of a novel foraging video game. Step distributions from participants' behavior in-game were fit to Levy-like power law models and compared against non-power law models for closest fit to the true data. The second was investigating the significance of curiosity in trail deviation by administering the Kashdan 5-Dimensional Curiosity Scale to measure trait curiosity and comparing that to participants' frequency of pursuing curiosity probe stimuli. Overall, participants were found to exhibit Levy walks both when searching for and within resource patches, and diffusivity of search was positively related to suc (open full item for complete abstract)

Committee: Heath Demaree (Committee Chair); Michael Benard (Committee Member); Arin Connell (Committee Member); Lee Thompson (Committee Member) Subjects: Experimental Psychology; Psychology

Master of Science, The Ohio State University, 2020, Environment and Natural Resources

Urbanization can have profound influences shaping patterns of songbird diversity. For many species, urbanization poses considerable challenges, yet in many instances urban areas provide important habitat for songbirds, most notably riparian urban areas. With renewed interest to maintain functioning urban forests, understanding the interactions between songbirds and their urban environments is critical to making informed land management decisions. My research addresses habitat usage of breeding urban songbirds in Columbus, Ohio, focusing on the relationship between urban songbird presence and behavior and the vegetation in urban riparian forests. Previous songbird studies have been conducted in the Columbus metropolitan area since 2001 and have focused primarily on the impacts of urbanization on abundance, nesting, and survival. My goals for this study were to add to this knowledge base by examining potential correlations between songbird territory density and structural vegetative characteristics in urban forests and to investigate the foraging strategies of urban songbirds. The first component of my study examines the relationship between the breeding territory densities of individual songbird species and the vegetation structure of urban sites. Given that vegetation structure has been linked to urban songbird abundance and survival, the number of trees, the size of trees, and the density of exotic or native stems in a site may influence the territory density of certain species. I tested the hypotheses that overall songbird territory density will be greater in areas will fewer exotic stems and Neotropical territory density will increase with structural diversity. I conducted spot maps in urban riparian forests in Columbus, Ohio from late April to August in 2019 and compared these data to spot maps conducted by my colleagues in 2007 and 2011 to determine territory densities for the most common species, which included the Blue-gray Gnatcatcher, Blue Jay, Carolina (open full item for complete abstract)

Committee: Stephen Matthews PhD (Advisor); G. Matthew Davies PhD (Committee Member); Charles Flower PhD (Committee Member); Christopher Tonra PhD (Committee Member) Subjects: Urban Forestry; Wildlife Conservation; Wildlife Management

PhD, University of Cincinnati, 2024, Engineering and Applied Science: Electrical Engineering

Echolocating bats demonstrate sonar's remarkable ability to support various complex tasks, from navigating dense vegetation to foraging in flight. However, achieving these tasks using echolocation alone presents challenges due to the inherent limitations of sonar. Drawing inspiration from biological systems, we can narrow the performance gap between artificial and biological sonar. In this context, we develop behavior-based systems using sensorimotor loops and their interactions to accomplish the foraging task. We showcase a solution to the foraging task by training machine learning models to arbitrate between the approach and avoid sensorimotor loops using solely echoes as perception inputs. These models demonstrate a high success rate in foraging for insect-like targets and flower targets. In addition, they are robust against different arena geometries, traps, and noisy motor control. While arbitrating between the two sensorimotor loops proves effective, the system does not demonstrate attention to a single target, failing to investigate a flower target thoroughly. To address this, we develop a novel sensorimotor loop, termed the flower home-in loop, designed to guide nectarivorous bats toward a flower opening while maintaining attention on the target. The flower home-in loop perfectly performs when approaching the flower from the front. However, the performance gets worse when approaching the flower from other sides. Continuously re-estimating the target flower pose and updating the bat's path is a more robust strategy for the flower home-in loop in acoustically ambiguous scenarios. The flower home-in loop can also guide the bat toward the echoes from a flower's opening while being interfered with by echoes from nearby objects.

Committee: Dieter Vanderelst Ph.D. (Committee Chair); Ali Minai Ph.D. (Committee Member); Herbert Peremans Ph.D M.A B.A. (Committee Member); John Gallagher Ph.D. (Committee Member); Zachariah Fuchs Ph.D. (Committee Member) Subjects: Robotics

Bachelor of Arts (BA), Ohio University, 2024, Geography

In a world where foraging is as popular as ever, it is becoming increasingly important for management agencies to develop strategies to address this activity. The response by management agencies has not been uniform, nor has their effect on the foraging community. Because of this novelty and irregularity, it is important to study the political ecology of foraging policy. In this study, I take a closer look at the people who harvest nontimber forest products (NTFPs), the people who manage forests, and the relationship between these two groups.

Committee: Harold Perkins (Advisor) Subjects: Geography

Master of Science, The Ohio State University, 2023, Environment and Natural Resources

The American elm (Ulmus americana) was once found lining the streets of many cities. Now, with the continued threat of Dutch elm disease (Ophiostoma ulmi and O. novo-ulmi), large American elms are uncommon. Efforts by researchers have led to the development of Dutch elm disease-tolerant American elm selections. Yet we have little understanding of how these selections may react to a range of environments when used in restoration. Our goal is to better understand how DED-tolerant elms differ in phenology across locations and genotypes to develop predictions for how they may respond to restoration and future climate change. In common gardens in central Ohio and northern New England, we tracked the progression, time to initiation and time to completion of budbreak and leaf-out, in DED-tolerant elms. We assessed individuals across five genotypes – Princeton, R18-2, Del-2, New Harmony, and Valley Forge – which have been cultivated to produce DED-tolerant lines. Phenological data, i.e., dates at which a tree's buds reached a given stage, collected in central Ohio over two field seasons (spring 2022 and spring 2023) and in New England over one field season (spring 2023) were used to determine the relationship between time and phenology, and the effects of location, year, genotype, and genotype interactions. Data on bird presence and use of elm trees in sites in central Ohio during spring 2023 were used to better understand the potential role of restored elms within the landscape. We found that year and location effects were significant at more stages than genotype or interaction effects – colder locations and the year with later spring warming tended to result in elms reaching key phenological stages later than warmer locations and the year with earlier spring warming. This indicates that environmental factors may have a stronger influence on spring phenology in American elms than genotype. We also found that bird presence had a strong positive correl (open full item for complete abstract)

Committee: Stephen Matthews (Advisor); Jo Peacock (Committee Member); Matt Davies (Committee Member); Kristin Mercer (Advisor) Subjects: Forestry; Natural Resource Management

Master of Science, The Ohio State University, 2023, Evolution, Ecology and Organismal Biology

Hypoxia, or low concentration of dissolved oxygen in the water, is becoming a more frequent and extensive phenomenon in many aquatic ecosystems around the world, impacting the ecology of lakes, estuaries, and marine fishes. This often-recurring state of low oxygen degrades habitat quality, affects fish physiology, and can lead to changes in the behavior and distribution of species. Hypoxia can alter predator-prey dynamics through species-specific responses to low oxygen and changes spatiotemporal distributions of populations. The central basin of Lake Erie experiences seasonal hypolimnetic hypoxia every year due to a combination of natural thermal stratification and human practices. Lake Erie supports ecologically important and lucrative recreational and commercial fisheries, so considerable research has gone into understanding the impacts of hypoxia on the Lake Erie ecosystem. In the last decade, adult yellow perch (Perca flavescens) catch in the central basin of Lake Erie has significantly declined, raising questions about the drivers of decreases in yellow perch catch. The goal of this research was to gain better understanding about how hypoxia and other environmental variables associated with the hypoxic season (i.e. higher temperatures) influence adult (2+) yellow perch distributions and overall abundance as well as their diets and foraging behavior. Towards this goal, we conducted hydroacoustic surveys, analyzed data from 2021 annual Ohio Department of Natural Resources – Division of Wildlife trawl surveys, collected data on environmental variables, quantified adult yellow perch stomach contents, and collected data on zooplankton and benthic macroinvertebrates. In the first chapter, we used paired bottom trawl-hydroacoustic surveys to investigate the effects of hypoxia on adult yellow perch distributions. We compared where yellow perch were located in the water column (both fish and site depth) and yellow perch densities between sampling months. The second cha (open full item for complete abstract)

Committee: Elizabeth Marschall (Advisor); Stuart Ludsin (Committee Member); Roman Lanno (Committee Member) Subjects: Biology; Ecology; Environmental Science; Freshwater Ecology

Doctor of Philosophy, The Ohio State University, 2022, Entomology

Termite sociality is commonly assumed to be similar to ants when in fact, termites inhabit a wide array of niche. Variation in the life history of termites is most evident in nest types, and termites display adaptive behaviors most appropriate to the ecological challenges associated with their nesting habit. Termite nest types are categorized into one-piece, the drywood and dampwood termites colonizing a single wooden piece, intermediates, the subterranean termites colonizing multiple resources via underground tunnels, and separate, the higher termites that include the builders of elaborate mounds. Foraging behaviors of termites, which occurs in the phases of discovery, quality assessment, and recruitment, and are impacted by different nest habits of termites. Various mechanisms of resource quality assessment have been observed in one-piece termites, as a colony consumes a single resource colonized by the founding reproductive. In contrast, due to the need to relocate resources to a centralized nest, separate nest types have developed efficient recruitment mechanisms. Intermediate nest type termites construct tunnels to forage and must efficiently discover resources, as well as have mechanisms to distribute nestmates among feeding sites. Numerous cues associated with the foraging behaviors of subterranean termites have been identified, yet how these mechanisms are integrated into a system of effective foraging strategy has not been considered. In particular, several cues suggested to mediate search patterns are likely involved in later stages of settlement at resources instead. Therefore, further investigations are necessary to determine what cues subterranean termites use to initially discover food resources. The first objective was to investigate termite response to distant odors from wood and nestmates and determine whether this behavioral response was due to attraction or arrestment. The response of Reticulitermes flavipes (Kollar) workers to wood and nestma (open full item for complete abstract)

Committee: P Larry Phelan (Advisor); Rachelle Adams (Committee Member); David Shetlar (Committee Member); Christopher Ranger (Committee Member); Reed Johnson (Committee Member) Subjects: Entomology

Doctor of Philosophy (PhD), Wright State University, 2021, Interdisciplinary Applied Science and Mathematics PhD

Counterfactual reasoning can be used in task-switching scenarios, such as design and planning tasks, to learn from past behavior, predict future performance, and customize interventions leading to enhanced performance. Previous research has focused on external factors and personality traits; there is a lack of research exploring how the decision-making process relates to both task-switching and counterfactual predictions. The purpose of this dissertation is to describe and explain individual differences in task-switching strategy and cognitive processes using machine learning techniques and linear ballistic accumulator (LBA) models, respectively, and apply those results in counterfactual models to predict behavior. Applying machine learning techniques to real-world task-switching data identifies a pattern of individual strategies that predicts out-of-sample clustering better than random assignment and identifies the most important factors contributing to the strategies. Comparing parameter estimates from several different LBA models, on both simulated and real data, indicates that a model based on information foraging theory that assumes all tasks are evaluated simultaneously and holistically best explains task-switching behavior. The resulting parameter values provide evidence that people have a switch-avoidance tendency, as reported in previous research, but also show how this tendency varies by participant. Including parameters that describe individual strategies and cognitive mechanisms in counterfactual prediction models provides little benefit over a baseline intercept-only model to predict a holdout dataset about real-world task switching behavior and performance, which may be due to the complexity and noise in the data. The methods developed in this research provide new opportunities to model and understand cognitive processes for decision-making strategies based on information foraging theory, which has not been considered previously. The results from this (open full item for complete abstract)

Committee: Ion Juvina Ph.D. (Advisor); Joseph W. Houpt Ph.D. (Committee Member); Valerie L. Shalin Ph.D. (Committee Member); Zheng Xu Ph.D. (Committee Member) Subjects: Applied Mathematics; Cognitive Psychology; Mathematics; Psychology

Doctor of Philosophy, The Ohio State University, 2021, Entomology

Global populations of bees are in decline, threatening the stability of crop production and disrupting ecological communities. Unexpectedly, cities can harbor rich assemblages and sometimes rare species of bees. Thus, urban areas are increasingly recognized as potential refuge habitats for declining pollinators and as important targets for future bee conservation. Current urban bee populations are thought to be supported by residential gardens, parks, vacant lots and urban farms, which can contain a high floral abundance and therefore foraging resources for bees. Yet, there is no clear consensus about what drives the abundance and distribution of wild bees across cities. We also have little knowledge about how urbanization affects bee fitness, including their reproduction and health. For cities to achieve their conservation potential, we need to better understand what constitutes a high-quality urban habitat and how management can optimize urban greenspace for bee foraging and nesting. Herein, I examine patterns of bee biodiversity, nesting success, and resource capture within Cleveland, Ohio, USA as a case study for urban pollinator conservation. Cleveland is one of 350 legacy cities worldwide which are promising candidates for future bee conservation due to their high abundance of vacant urban land. For example, following protracted economic decline, Cleveland, Ohio now contains over 27,000 vacant properties, representing 1,600 ha of vacant land. While extensive vacant land can be perceived as blight, it has also provided a transformative opportunity for the city of Cleveland to invest in urban greening initiatives, including more than 235 urban farms/community gardens and the large-scale urban field experiment which I conducted this research in. To contextualize current knowledge of urban pollinators, I first review how greenspace design, management, and landscape context alter urban habitat's value for bees (Chapter 1). In addition, I assert that pollina (open full item for complete abstract)

Committee: Mary Gardiner (Advisor); Carol Anelli (Committee Member); Reed Johnson (Committee Member); Norman Johnson (Committee Member) Subjects: Conservation; Ecology; Entomology; Urban Planning

Doctor of Philosophy, University of Akron, 2020, Integrated Bioscience

Carotenoid ornaments are colorful sexual features, created when animals deposit diet-derived carotenoid pigments into an integument, such as skin. Debate has ensued over whether these ornaments can signal aspects of foraging ability, diet quality, and direct benefits. In this dissertation, I explore how natural variation in diet and foraging behavior (measured via stable isotope analyses and GPS tracking) relates to carotenoid skin color in the brown booby (Sula leucogaster). I demonstrate a robust relationship between diet, foraging behavior and carotenoid ornament quality in both males and females. In Chapter 2 I show that increased green gular skin ornamentation of male boobies from Islas Marietas, Mexico is linked to more pelagic diet, as indicated by GPS tracking results and lower d13C blood plasma values. The base of pelagic food webs is composed of phytoplankton, which have higher concentrations of the xanthophyll class of carotenoid pigments (found in brown booby ornaments) compared to benthic algae. Limited access to distant, pelagic food webs may lead to rarity of carotenoids in male brown booby diet, with only skilled foragers able to generate a high-quality ornament. In Chapter 3, I examine the influence of inter-colony foraging environment variation on brown booby carotenoid ornament honesty. I investigate the relationship between diet/foraging and ornaments at three colonies distributed across an ecological gradient of depth. At all colonies, ornament quality is closely linked to diet and foraging, measured by d13C of blood plasma and GPS tracking. However, the colonies vary in which trait (foot vs. gular skin color) is associated with foraging metrics and which foraging attributes were linked to more colorful ornaments (e.g. longer trips/pelagic diet in deeper waters vs. short trips/benthic diet in shallow waters). Finally, in Chapter 4 I examine whether female brown booby ornaments are also honest indicators of foraging, diet, and parental c (open full item for complete abstract)

Committee: Randall Mitchell (Advisor); Anne Wiley (Committee Member); Daniel Thomas (Committee Member); John Senko (Committee Member); Donald Ott (Committee Member) Subjects: Biogeochemistry; Ecology; Evolution and Development; Zoology

Master of Science, The Ohio State University, 2020, Evolution, Ecology and Organismal Biology

Loss of habitat is one of the drivers of bee declines worldwide. However, conservation and habitat recreation often solely focus on the establishment of forbs as a pollen and nectar source while disregarding other resources that bees need to gather from their landscapes. The family Megachilidae is a large and diverse assemblage of bee species, the majority of which require non-floral resources for nest building. Leaf-cutter bees (genus Megachile) are perhaps the most well-known bees within the family, using cut pieces of leaves to build their nests. Like all bees, Megachile are central place foragers, requiring all of their food plants, as well as suitable leaves for nest construction, within a limited foraging range of their nest. Each female builds her nest within a tunnel in wood or a hollow stem where she constructs a linear series of brood cells lined with cut discs of leaves that protect her offspring and pollen provisions from parasites and desiccation. Poor quality leaves incur fitness costs for the female bee, including longer processing time and excessive mandibular wear. These costs drive strong preferences for specific species of leaves. I investigated the leaf traits that influence preference in Megachile to better understand how variation in vegetation surrounding the nest might limit bee success through the availability of high-quality leaves. This study focuses on reclaimed coal surface mines in Eastern Ohio because they exhibit variation in vegetation at a landscape scale relevant to bee foraging. Reclaimed mines also present novel ecological conditions that can be used to establish habitat for bee conservation. First, I described the physical characteristics of leaves found on a reclaimed mine in order to determine traits associated with leaf choice. This study focused on a representative species of leaf-cutter bee, Megachile rotundata, because of its abundance at the study site and the availability of published data on the species of leaves it (open full item for complete abstract)

Committee: Karen Goodell PhD (Advisor); Rachelle Adams PhD (Committee Member); Frances Sivakoff PhD (Committee Member); Rebecca Swab PhD (Committee Member) Subjects: Biology; Conservation; Ecology; Entomology; Environmental Management

Master of Science, University of Akron, 2019, Biology

Ecological study of the spatial aspects of plant-pollinator interactions tends to follow lines of inquiry that begin with either plants as habitat or pollinators as decision-making agents. Small-scale insect behavior in response to flowering plants does not necessarily extend to larger scales. How insects navigate a landscape between patches of foraging habitat remains difficult to assess. The discrete distribution and self-incompatibility of Apocynum cannabinum facilitated this study of the effects of patch density and distribution on pollinator visits and plant reproductive output. No effect of density or inter-patch distance on pollinator visits or fruit set was observed. Density had a positive effect on seed set, which ranged from 65-103 seeds per fruit. Pollinator visits were dominated by species in the orders Hymenoptera and Lepidoptera and included previously unreported species. The reproductive strategy of Apocynum cannabinum suggests that abundant and prolonged flowering encourages sufficient between-patch movements by an effective pollinator able to access and transfer pollen from the modified flower. Visible landscape structure was an indicator of ecological connectivity - pollinators easily traversed the distance between the furthest apart patches - but the study scale did not shed light on barriers or gaps in connectivity.

Committee: Randall J. Mitchell (Advisor); Linda R. Barrett (Committee Member); Stephen C. Weeks (Committee Member) Subjects: Botany; Ecology; Entomology; Plant Biology

Doctor of Philosophy, The Ohio State University, 2018, Entomology

While numerous factors currently impact the health of honey bees and other pollinating Hymenoptera, poor floral resource availability due to habitat loss and land conversion is thought to be important. This issue is particularly salient in the upper Midwest, a location which harbors approximately 60 percent of the US honey bee colonies each summer for honey production. This region has experienced a dramatic expansion in the area devoted to crop production over the past decade. Consequently, understanding how changes to landscape composition affect the diversity, quality and quantity of available floral resources has become an important research goal. Here, I developed molecular methods for the identification of bee-collected pollen by adapting and improving upon the existing amplicon sequencing infrastructure used for microbial community ecology. In thoroughly benchmarking our procedures, I show that a simple and cost-effective three-step PCR-based library preparation protocol in combination with Metaxa2-based hierarchical classification yields an accurate and highly quantitative pollen metabarcoding approach when applied across multiple plant markers. In Chapter 1, I conducted one of the first ever proof-of-concept studies applying amplicon sequencing, or metabarcoding, to the identification of bee-collected pollen. In this work, we used rudimentary laboratory and bioinformatic methods to apply the method to a single nuclear marker, ITS2. In doing so, we found the method to be highly inaccurate with respect to quantitative inference of the relative abundances of different plant taxa represented within our sample. Thus, in Chapter 2 I used the same methods and turned my attention to two alternative chloroplast markers, matK and rbcL, in addition to ITS2. In this study, I found that the chloroplast markers were more useful for quantification of pollen abundance relative to ITS2. With an improved understanding of the behavior of different plant markers, I began op (open full item for complete abstract)

Committee: Reed Johnson (Advisor); John Christman (Committee Member); Mary Gardiner (Committee Member); Roman Lanno (Committee Member) Subjects: Agriculture; Bioinformatics; Biology; Ecology; Entomology; Pollen

MS, University of Cincinnati, 2018, Engineering and Applied Science: Computer Science

Work in information foraging theory presumes that software developers have a prede- fined patch of information (e.g., a Java class) within which they conduct a search task. However, not all tasks have easily delineated patches. Requirements traceability, where a developer must traverse a combination of technical artifacts and social structures, is one such task. We examine requirements socio-technical graphs to describe the key re- lationships that a patch should encode to assist in a requirements traceability task. We then present an algorithm, based on spreading activation, which extracts a relevant set of these relationships as a patch. We test this algorithm in requirements repositories of four open-source software projects. Our results show that applying this algorithm creates useful patches with reduced superfluous information.

Committee: Nan Niu Ph.D. (Committee Chair); Chia Han Ph.D. (Committee Member); Carla Purdy Ph.D. (Committee Member) Subjects: Computer Science

PhD, University of Cincinnati, 2017, Engineering and Applied Science: Computer Science and Engineering

Software engineering is the application of engineering to the development of software in a systematic method. Traditionally, professional software engineers use technologies and practices from a variety of fields to improve their productivity in creating software and to improve the quality of the delivered product. The practices come from aspects of software requirements, software design, software testing, software development process, and software quality, etc. Nowadays, more and more non-professional developers start to write programs not as their job function, but as means to support their main goal, which is something else, such as accounting, designing a webpage, doing office work, scientific research, entertainment, etc. The number of non-professional developers is already several times the number of professional programmers, and even students of elementary school start to learn simple programming tool skills. However, due to the varied purposes of developing software, the software engineering practices for these non-professional developers can be quite different from the practices for professional developers. The programming behavior of non-professional developers has characteristic of opportunistic, which lacks systematic guidelines, and the software created by them tends to lack enough quality considerations. Therefore, support from software engineering area is needed to improve end-user programmers' productivity and to increase the quality of the software developed. In this thesis, we define these non-professional developers as end-uesr developers and identify the distinctions between end-user developers and professional developers including the concept and programming practices of requirements, specifications, documentation, reuse, testing and verification, and debugging. We then identify that the pragmatic software reuse is the main approach adopted by end-user developers to fulfill their daily programming tasks. We conduct several rounds of observationa (open full item for complete abstract)

Committee: Nan Niu Ph.D. (Committee Chair); Raj Bhatnagar Ph.D. (Committee Member); Carla Purdy Ph.D. (Committee Member); Michael Sokoloff Ph.D. (Committee Member); Michael Wagner Ph.D. (Committee Member) Subjects: Computer Science

Master of Science, The Ohio State University, 2017, Environment and Natural Resources

The northward spread of the non-native, invasive filter feeding crab Petrolisthes armatus into oyster reef communities along the Southeastern US is hypothesized to be limited by cold snaps associated with northern winters. However, several native predators in oyster reefs have been shown to consume this abundant and profitable prey item, suggesting that biotic resistance through predation may be an additional factor limiting its northward spread. My objectives were to 1) determine if the per capita predation risk exerted by native predators might be a factor that explains the current distribution of P. armatus, and 2) test whether the relative abundance of alternative native prey affects the consumption and preference of P. armatus by a native predatory crab Panopeus herbstii. I conducted a field study to quantify predation risk across 8 invaded estuary sites from St. Augustine, FL to North Inlet, SC and conducted a lab experiment to quantify the consumption of P. armatus when in low to high abundance relative to alternative native prey. While predation rates were high (68.2 – 98.2%) across sites, there was no relationship between predation and latitude across the 8 invaded estuaries. Furthermore, while P. herbstii increased consumption of P. armatus in response to increased abundance in the tank, P. herbstii always showed a preference for native prey regardless of its relative abundance. Overall, I found no evidence of biotic resistance through predation, suggesting that native predators do not prevent the spread of P. armatus and this species is likely to continue its expansion into northern waters as sea temperatures increase with climate change.

Committee: Lauren Pintor Dr. (Advisor); Stuart Ludsin Dr. (Committee Member); Christopher Tonra Dr. (Committee Member); James Byers Dr. (Committee Member) Subjects: Ecology; Environmental Studies; Natural Resource Management

MS, University of Cincinnati, 2017, Engineering and Applied Science: Mechanical Engineering

Design of robot swarms inspired by self-organization in social insect groups is currently an active research area with a diverse portfolio of potential applications. This thesis is focused on the development of control laws for swarm of robots inspired by ant foraging. Particularly, this work presents control laws for efficient area coverage by a robot swarm in a 2D spatial domain, inspired by the unique dynamical characteristics of ant foraging. The novel idea pursued in the effort is that dynamic, adaptive switching between Brownian motion and Levy flight in the stochastic component of the search increases the efficiency of the search and area coverage. The study is motivated by behaviors of certain biological studies who exhibit searching patterns modeled using Levy flight. Influence of different pheromone (the virtual chemotactic agent that drives the foraging) threshold values for switching between Levy flights and Brownian motion is studied using two performance metrics - area coverage and visit entropy. The results highlight the advantages of the switching strategy for the control framework, particularly in cases when the object of the search is scarce in quantity or getting depleted in real-time.

Committee: Manish Kumar Ph.D. (Committee Chair); Ali Minai Ph.D. (Committee Member); David Thompson Ph.D. (Committee Member) Subjects: Mechanical Engineering; Mechanics

Master of Arts, The Ohio State University, 2017, Anthropology

Resource specialists have low dietary diversity and a high reliance on certain food sources due to behavioral or morphological adaptations. Specialists, who rely on a narrow range of habitats or food sources, tend to have restricted geographic ranges and are vulnerable when their preferred foods diminish. Identifying the relative vulnerability of resident primate species is of vital importance as anthropogenic disturbances and large-scale climate change alter the availability of potential food sources. Long term data indicate that several species of East African red colobus (Piliocolobus tephrosceles, Piliocolobus rufomitratus, and Piliocolobus kirkii) display significant inter and intra annual dietary variation. Much less is known about the extent of variation in the diets of West African red colobus. This study examines long term feeding data from one groups of Western red colobus (Piliocolobus badius badius) ranging in Cote d'Ivoire's Tai Forest to test the hypothesis that changes in phenological productivity have resulted in significant changes in dietary diversity. All data were collected by Amanda Korstjens (2001) and assistants of the Tai Monkey Project. Feeding profiles were created through hourly scan samples, which indicate whether an individual was feeding and if so, what species and plant part was consumed. Phenological data were collected from 59 tree species on three transects biweekly; each tree was given an abundance score of 0 - 3. Shannon-Weiner Indices indicate significant decreases in dietary diversity between 1997 and 2015 (p<0.01). It is clear that fewer plant species are comprising a greater bulk of the diet over the study period. However, no apparent changes in phenological patterns of any individual plant parts were revealed. Further analysis of nutritional components and other elements of selectivity is needed to identify why specific plants are so vital to the diets of P. badius badius. Identifying those elements of the red colobus diet th (open full item for complete abstract)

Committee: W. Scott McGraw (Advisor); Kristen Gremillion (Committee Member); Mark Hubbe (Committee Member) Subjects: Animal Sciences; Ecology

Doctor of Philosophy, The Ohio State University, 2017, Evolution, Ecology and Organismal Biology

Interactions between predators and prey are widespread in nature but the ecological and evolutionary factors that shape these interactions are poorly understood. In my dissertation, I use pigmy rattlesnakes (Sistrurus miliarius) and their prey as a system in which to examine several aspects of this species interaction where different ecological and evolutionary factors may be shaping variation in adaptive traits. In Chapter 1, I review factors affecting predator-prey interactions and explain why the pigmy rattlesnake system is valuable for addressing important research questions. In Chapter 2, I present research on the behavioral component of this interaction, demonstrating that native cotton mice do not change their foraging behavior in the presence of a sit-and-wait rattlesnake predator. In Chapter 3, I explore the toxicity of venom to native prey versus non-native "models" to determine to what extent non-native species are representative of prey in the same broad taxonomic group. I show that native prey have higher resistance to venom than non-natives and encourage the use of native prey in future toxicity work. In Chapter 4, I use native treefrog prey from two different populations in Florida and venom from snakes in the same populations to see if there is a signal of local adaptation present in these populations. I show that detection of a signal of local adaptation depends on the measure of venom function used: evidence for local adaptation was observed in the time to death measure of mortality but not in the 24 hour mortality measure. In Chapter 5, I look at the function of venom at a smaller scale by exploring the amount of functional variation present across and within populations of snakes using a lizard model prey. I found the individual component of venom toxicity to be larger than the population-level differences that have been the focus of previous research. Overall, this dissertation demonstrates that rattlesnake venom function differs at bo (open full item for complete abstract)

Committee: H. Lisle Gibbs Ph.D. (Advisor); Ian Hamilton Ph.D. (Committee Member); Thomas Hetherington Ph.D. (Committee Member); Stuart Ludsin Ph.D. (Committee Member) Subjects: Animals; Behavioral Sciences; Biology; Ecology; Evolution and Development; Toxicology; Zoology

Doctor of Philosophy, The Ohio State University, 2016, Entomology

The unifying thesis of my dissertation is that the biology of a honey bee colony cannot be understood apart from the landscape in which it lives; this influence of landscape applies especially to honey bee foraging biology and toxic exposure, and consequently to apicultural outcomes. In Chapter 1, I present and elaborate this thesis in the context of existing literature and lay out the scope of my dissertation accordingly. In Chapter 2, I describe a study in which I collaborated with volunteer beekeepers to measure the success of honey bee colonies surrounded by different types of landscape in Ohio, USA. The results of this study showed that the most successful colonies tended to be those surrounded by agricultural land as opposed to those in forested or urban landscapes, which was contrary to the prevailing opinion that agricultural landscapes are too dominated by crop monocultures and too contaminated with pesticides to support healthy honey bees. This led me to hypothesize that the relationship between honey bee success and landscape is driven mainly by the availability of certain key floral taxa that, in Ohio, occur most abundantly in the interstices of the agricultural landscape. Chapter 3 further pursues the question of whether honey bees prefer agricultural or urban land use by setting up a foraging choice test between these two landscape types. Using a combination of dance language analysis and pollen identification, I monitored the spatial and taxonomic patterns of honey bee foraging at an apiary located on the interface of urban and agricultural land use. The results indicate a strong and consistent preference for the agricultural landscape, corroborating the results of Chapter 1 with an independent data set and using different lines of evidence. In Chapter 4, I turn my attention to the issue of toxic exposure, constructing a critical review of existing approaches to modeling toxic exposure in honey bees. All existing approaches suffer from seriou (open full item for complete abstract)

Committee: Reed Johnson (Advisor); Casey Hoy (Committee Member); Mary Gardiner (Committee Member); Karen Goodell (Committee Member) Subjects: Biology; Ecology; Entomology; Toxicology