Matching Items (95)
Description
Bioindicators of wildlife health are useful tools for studying the viability of various organisms and populations, and can include a range of phenotypic variables, such as behavior, body size, and physiological parameters, such as circulating hormones and nutrients. Few studies have investigated the utility of total plasma protein as a predictor of environmental or nutritional variation among birds, as well as variation across different seasons and life-history stages. Here I examined relationships between plasma protein and season, urbanization, sex, body condition, molt status, and disease state in house finches (Haemorhous mexicanus). I sampled blood from house finches across three seasons (winter, summer and fall 2021) and measured plasma protein levels using a Bradford assay. I also collected data including condition, sex, and poxvirus infection state at capture, as well as fecal samples to assess gut parasitism (coccidiosis). During the fall season I also estimated molt status, as number of actively growing feathers. I found circulating plasma protein concentration to be lower in the fall during molt than during winter or summer. I also found a significant relationship between circulating protein levels and capture site, as well as novel links to molt state and pox presence, with urban birds, those infected with pox, and those in more intense molt having higher protein levels. My results support the hypotheses that plasma protein concentration can be indicative of a bird’s body molt (which demands considerable protein for feather synthesis) and degree of habitat urbanization, although future work is needed to determine why protein levels were higher in virus-infected birds.
ContributorsDrake, Dean (Author) / McGraw, Kevin (Thesis director) / Sweazea, Karen (Committee member) / Jackson, Daniel (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2022-05
Description
Political boundaries often divide ecosystems and create the challenge of conserving the ecosystem across borders. Through transboundary ecosystem management multiple groups can come together and manage the ecosystem that spans their borders collaboratively. In the United States there are several examples of ecosystems that span borders, such as the Sonoran Desert along the US-Mexico frontier and the Rocky Mountains running through the US and Canada. To gain insight into what leads to effective transboundary resource management I compared two case studies that manage resources over borders with multiple collaborators: Glacier National Park and Organ Pipe Cactus National Monument. These two cases offer contrasting ecosystems and backgrounds in transboundary resource management in the United States. To compare the cases I coded them using a collaborative governance codebook (Schoon et al. 2020). The codebook uses a Context-Mechanisms-Outcomes framework to identify aspects of collaborative governance and contextual factors present in each park (Pawson & Tilley 1997; Salter & Kothari, 2014). Once coded, the cases were compared to identify what aspects were similar and different in the parks to help potentially explain what features did or did not lead to effective transboundary resource management.
ContributorsTaetle, Noah (Author) / Schoon, Michael (Thesis director) / Carr Kelman, Candice (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Politics and Global Studies (Contributor)
Created2022-05
Description
Heavy metals and persistent organic pollutants contribute to human health risks worldwide. Among the most common routes of exposure to pollutants for humans are through the consumption of contaminated water and food, with fish being among the greatest vectors for ingestion of heavy metals in humans, particularly mercury.This dissertation consists of three chapters with a central theme of investigating heavy metal and persistent organic pollutant concentrations in fish and corned beef, which are two commonly consumed food items in American Samoa. A literature review illustrated that historically the primary pollutants of concern in fish muscle tissue from American Samoa have been mercury, arsenic, and polycyclic aromatic hydrocarbon mixtures. To better understand the changes in heavy metals and persistent organic pollutants in fish, this study reports an updated data set, comparing concentrations in pollutants as they have changed over time. To further investigate pollutants in fish tissue, 77 locally caught and commonly consumed fish were analyzed for heavy metals and persistent organic pollutants, and baseline human health risk assessments were calculated for contaminants that had available oral reference doses. While in American Samoa collecting fish for contaminant analyses, it was realized that canned corned beef appeared to be more commonly consumed than fresh fish. An IRB approved consumption survey revealed that 89% of American Samoan adults regularly consume fish, which is the same percentage of people that reported eating canned corned beef, indicating a dramatic increase in this food item to their diet since its introduction in the 20th century.
Results of this study indicate that fish muscle tissue generally has higher heavy metal concentrations than canned corned beef, and that mercury continues to be a main contaminant of concern when consuming fresh and canned fish in American Samoa. While none of the heavy metal concentrations in corned beef exceeded calculated action levels, these foods might contribute to negative health outcomes in other ways. One of the main findings of this study is that either the presence or the ability to detect persistent organic pollutant concentrations are increasing in fish tissue and should be periodically monitored to adequately reflect current conditions.
ContributorsLewis, Tiffany Beth (Author) / Polidoro, Beth (Thesis advisor) / Neuer, Susanne (Thesis advisor) / Halden, Rolf (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
Effective collaboration and cooperation across difference are at the heart of present and future sustainability challenges and solutions. Collaboration among social groups (intragenerational), across time (intergenerational), and across species (interspecies) is each central to achieving sustainability transitions in the 21st century. In practice, there are three types of differences that limit collaboration and cooperation toward sustainability outcomes: differences among social groups, differences across time, and differences across species. Each of these differences have corresponding cognitive biases that challenge collaboration. Social cognitive biases challenge collaboration among social groups; temporal cognitive biases challenge collaboration across time; and anthropocentric cognitive biases challenge collaboration across species. In this work, I present three correctives to collaboration challenges spanning the social, temporal, and species cognitive biases through intervention-specific methods that build beyond traditional framings of empathy, toward social, futures, and ecological empathy. By re-theorizing empathy across these domains, I seek to construct a multidimensional theory of empathy for sustainability, and suggest methods to build it, to bridge differences among people, time horizons, and species for sustainability practice.
ContributorsLambert, Lauren Marie-Jasmine (Author) / Selin, Cynthia (Thesis advisor) / Schoon, Michael (Thesis advisor) / Tomblin, David (Committee member) / Berbés-Blázquez, Marta (Committee member) / Arizona State University (Publisher)
Created2023
Description
Wildlife rehabilitation as a practice in the United States exists in a complicated ethical landscape. The Wildlife Rehabilitator's Code of Ethics exists to guide the profession and states that rehabilitators must respect the wildness and maintain the dignity of an animal in their care. This thesis explores the question: How do the attitudes and actions of wildlife rehabilitators exemplify the ways in which they understand and enact respect for an animal’s dignity and wildness while in their care? Additionally, in what circumstances do rehabilitators align and diverge from each other in their interpretation and demonstration of this respect? These questions were answered through a literature review, interviews with rehabilitators, and site visits to wildlife rehabilitation centers in the Phoenix metropolitan area. My results suggest that rehabilitators are aligned in their understanding of respect for wildness and dignity as it applies to the animals in their care that are actively undergoing rehabilitation. Rehabilitators achieved consensus on the idea that they should interact with the animals as little as possible while providing their medically necessary care. Rehabilitators began to diverge when considering the animals in their sanctuary spaces. Specifically, they varied in their perception of wildness in sanctuary animals, which informed how some saw their responsibilities to the animals. Lesser perceived wildness correlated to increased acceptance of forming affectionate relationships with the sanctuary animals, and even feelings of obligation to form these relationships. Based on my research, I argue that the Wildlife Rehabilitator's Code of Ethics should be revised to reflect the specific boundary that wildlife rehabilitators identified in the rehabilitation space and provide substantive guidance as to what respecting wildness and dignity means in this field.
ContributorsBernat, Isabella Elyse (Author) / Minteer, Ben (Thesis advisor) / Ellison, Karin (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2023
Description
Though controversial in its utility to the scientific study of nonhuman animals, anthropomorphism, or the attribution of human characteristics to a nonhuman being, is omnipresent in our interactions with other animals. Anthropomorphism is undeniably a fixture of modern zoos, but how anthropomorphism relates to zoos’ contributions to conservation is unclear. In this dissertation, I investigate these potentially dueling, potentially overlapping, messages within great ape exhibits in accredited zoos. Given the complexity of both anthropomorphism and conservation, this dissertation reveals some nuances of how both play out in zoological spaces. Human psychology literature on anthropomorphism indicates that there are a variety of uses for this lens that benefit humans; from feeling we can understand a confusing animal action, to feeling social connection. Whereas the comparative psychology literature highlights a contested utility of anthropomorphism in studies of nonhuman animals. The main findings from this study are four-fold. Firstly, surveys conducted with zoo visitors show that many bring anthropomorphic beliefs with them on their trek through the zoo. Visitors are prone to viewing great apes as strikingly like humans in terms of emotions, emotional expression, and understanding of the world. Secondly, surveyed zoo visitors who agreed more with anthropomorphic statements also agreed more with statements about feeling interconnected with nature. Thirdly, there is no uniform understanding within the zoo community about how zoo exhibits do or should contribute to conservation efforts given that exhibits have multiple goals, one being the safety and wellness of their animal residents. Fourthly, interviews of zoo staff show that they mediate a variety of messages for zoo visitors and walk a sometimes-divisive line between when it’s acceptable to use anthropomorphic framing to discuss zoo animals and when it’s inaccurate. By leveraging a better understanding of these attitudes and relationships, zoos can further empower their staff to navigate these complex issues and improve their mission-based goal of promoting conservation outcomes by acknowledging the human practices embedded in our perceptions of and interactions with zoo animals. This work speaks to the importance of carefully considering the ways we understand animals in zoos, in the wild, and all the places in-between.
ContributorsLyon, Cassandra (Author) / Minteer, Ben A. (Thesis advisor) / Wynne, Clive D.L. (Committee member) / Maynard, Lily (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2024
Description
With global environmental systems under increasing Anthropogenic influence, conservationists and environmental managers are under immense pressure to protect and recover the world’s imperiled species and ecosystems. This effort is often motivated by a sense of moral responsibility, either to nature itself, or to the end of promoting human wellbeing over the long run. In other words, it is the purview of environmental ethics, a branch of applied philosophy that emerged in the 1970s and that for decades has been devoted to understanding and defending an attitude of respect for nature, usually for its own sake. Yet from the very start, environmental ethics has promoted itself as contributing to the resolution of real-world management and policy problems. By most accounts, however, the field has historically failed to deliver on this original promise, and environmental ethicists continue to miss opportunities to make intellectual inroads with key environmental decisionmakers. Inspired by classical and contemporary American philosophers such as Charles Sanders Peirce, William James, John Dewey, and Richard Rorty, I defend in this dissertation the virtues of a more explicitly pragmatic approach to environmental ethics. Specifically, I argue that environmental pragmatism is not only commensurate with pro-environmental attitudes but that it is more likely to lead to viable and sustainable outcomes, particularly in the context of eco-social resilience-building activities (e.g., local experimentation, adaptation, cooperation). In doing so, I call for a recasting of environmental ethics, a project that entails: 1) a conceptual reorientation involving the application of pragmatism applied to environmental problems; 2) a methodological approach linking a pragmatist environmentalism to the tradition and process of adaptive co-management; and 3) an empirical study of stakeholder values and perspectives in conservation collaboratives in Arizona. I conclude that a more pragmatic environmental ethics has the potential to bring a powerful set of ethical and methodological tools to bear in real-world management contexts and, where appropriate, can ground and justify coordinated conservation efforts. Finally, this research responds to critics who suggest that, because it strays too far from the ideological purity of traditional environmental ethics, the pragmatic decision-making process will, in the long run, weaken rather than bolster our commitment to conservation and environmental protection.
ContributorsRojas, Christopher A (Author) / Minteer, Ben A (Thesis advisor) / Carr Kelman, Candice (Committee member) / Kinzig, Ann (Committee member) / Schoon, Michael (Committee member) / Arizona State University (Publisher)
Created2019
Description
Reproduction is energetically costly and seasonal breeding has evolved to capitalize on predictable increases in food availability. The synchronization of breeding with periods of peak food availability is especially important for small birds, most of which do not store an extensive amount of energy. The annual change in photoperiod is the primary environmental cue regulating reproductive development, but must be integrated with supplementary cues relating to local energetic conditions. Photoperiodic regulation of the reproductive neuroendocrine system is well described in seasonally breeding birds, but the mechanisms that these animals use to integrate supplementary cues remain unclear. I hypothesized that (a) environmental cues that negatively affect energy balance inhibit reproductive development by acting at multiple levels along the reproductive endocrine axis including the hypothalamus (b) that the availability of metabolic fuels conveys alterations in energy balance to the reproductive system. I investigated these hypotheses in male house finches, Haemorhous mexicanus, caught in the wild and brought into captivity. I first experimentally reduced body condition through food restriction and found that gonadal development and function are inhibited and these changes are associated with changes in hypothalamic gonadotropin-releasing hormone (GnRH). I then investigated this neuroendocrine integration and found that finches maintain reproductive flexibility through modifying the release of accumulated GnRH stores in response to energetic conditions. Lastly, I investigated the role of metabolic fuels in coordinating reproductive responses under two different models of negative energy balance, decreased energy intake (food restriction) and increased energy expenditure (high temperatures). Exposure to high temperatures lowered body condition and reduced food intake. Reproductive development was inhibited under both energy challenges, and occurred with decreased gonadal gene expression of enzymes involved in steroid synthesis. Minor changes in fuel utilization occurred under food restriction but not high temperatures. My results support the hypothesis that negative energy balance inhibits reproductive development through multilevel effects on the hypothalamus and gonads. These studies are among the first to demonstrate a negative effect of high temperatures on reproductive development in a wild bird. Overall, the above findings provide important foundations for investigations into adaptive responses of breeding in energetically variable environments.
ContributorsValle, Shelley (Author) / Deviche, Pierre (Thesis advisor) / McGraw, Kevin (Committee member) / Orchinik, Miles (Committee member) / Propper, Catherine (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2018
Description
Why do many animals possess multiple classes of photoreceptors that vary in the wavelengths of light to which they are sensitive? Multiple spectral photoreceptor classes are a requirement for true color vision. However, animals may have unconventional vision, in which multiple spectral channels broaden the range of wavelengths that can be detected, or in which they use only a subset of receptors for specific behaviors. Branchiopod crustaceans are of interest for the study of unconventional color vision because they express multiple visual pigments in their compound eyes, have a simple repertoire of visually guided behavior, inhabit unique and highly variable light environments, and possess secondary neural simplifications. I first tested the behavioral responses of two representative species of branchiopods from separate orders, Streptocephalus mackini Anostracans (fairy shrimp), and Triops longicaudatus Notostracans (tadpole shrimp). I found that they maintain vertical position in the water column over a broad range of intensities and wavelengths, and respond behaviorally even at intensities below those of starlight. Accordingly, light intensities of their habitats at shallow depths tend to be dimmer than terrestrial habitats under starlight. Using models of how their compound eyes and the first neuropil of their optic lobe process visual cues, I infer that both orders of branchiopods use spatial summation from multiple compound eye ommatidia to respond at low intensities. Then, to understand if branchiopods use unconventional vision to guide these behaviors, I took electroretinographic recordings (ERGs) from their compound eyes and used models of spectral absorptance for a multimodel selection approach to make inferences about the number of photoreceptor classes in their eyes. I infer that both species have four spectral classes of photoreceptors that contribute to their ERGs, suggesting unconventional vision guides the described behavior. I extended the same modeling approach to other organisms, finding that the model inferences align with the empirically determined number of photoreceptor classes for this diverse set of organisms. This dissertation expands the conceptual framework of color vision research, indicating unconventional vision is more widespread than previously considered, and explains why some organisms have more spectral classes than would be expected from their behavioral repertoire.
ContributorsLessios, Nicolas (Author) / Rutowski, Ronald L (Thesis advisor) / Cohen, Jonathan H (Thesis advisor) / Harrison, John (Committee member) / Neuer, Susanne (Committee member) / McGraw, Kevin (Committee member) / Arizona State University (Publisher)
Created2016
Description
Foraging has complex effects on whole-organism homeostasis, and there is considerable evidence that foraging behavior is influenced by both environmental factors (e.g., food availability, predation risk) and the physiological condition of an organism. The optimization of foraging behavior to balance costs and benefits is termed state-dependent foraging (SDF) while behavior that seeks to protect assets of fitness is termed the asset protection principle (APP). A majority of studies examining SDF have focused on the role that energy balance has on the foraging of organisms with high metabolism and high energy demands ("high-energy systems" such as endotherms). In contrast, limited work has examined whether species with low energy use ("low-energy systems" such as vertebrate ectotherms) use an SDF strategy. Additionally, there is a paucity of evidence demonstrating how physiological and environmental factors other than energy balance influence foraging behavior (e.g. hydration state and free-standing water availability). Given these gaps in our understanding of SDF behavior and the APP, I examined the state-dependency and consequences of foraging in a low-energy system occupying a resource-limited environment - the Gila monster (Heloderma suspectum, Cope 1869). In contrast to what has been observed in a wide variety of taxa, I found that Gila monsters do not use a SDF strategy to manage their energy reserves and that Gila monsters do not defend their energetic assets. However, hydration state and free-standing water availability do affect foraging behavior of Gila monsters. Additionally, as Gila monsters become increasingly dehydrated, they reduce activity to defend hydration state. The SDF behavior of Gila monsters appears to be largely driven by the fact that Gila monsters must separately satisfy energy and water demands with food and free-standing water, respectively, in conjunction with the timescale within which Gila monsters balance their energy and water budgets (supra-annually versus annually, respectively). Given these findings, the impact of anticipated changes in temperature and rainfall patterns in the Sonoran Desert are most likely going to pose their greatest risks to Gila monsters through the direct and indirect effects on water balance.
ContributorsWright, Christian (Author) / Denardo, Dale F. (Thesis advisor) / Harrison, Jon (Committee member) / McGraw, Kevin (Committee member) / Sullivan, Brian (Committee member) / Wolf, Blair (Committee member) / Arizona State University (Publisher)
Created2014