Matching Items (8)
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- All Subjects: conservation
- All Subjects: Reptiles
- Status: Published
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
Description
Parental care provides many benefits to offspring. One widely realized benefit is enhanced regulation of offspring's thermal environment. The developmental thermal environment during development can be optimized behaviorally through nest site selection and brooding, and it can be further enhanced by physiological heat production. In fact, enhancement of the developmental thermal environment has been proposed as the initial driving force for the evolution of endothermy in bird and mammals. I used pythons (Squamata: Pythonidae) to expand existing knowledge of behavioral and physiological parental tactics used to regulate offspring thermal environment. I first demonstrated that brooding behavior in the Children's python (Antaresia childreni) is largely driven by internal mechanisms, similar to solitary birds, suggesting that the early evolution of the parent-offspring association was probably hormonally driven. Two species of python are known to be facultatively thermogenic (i.e., are endothermic during reproduction). I expand current knowledge of thermogenesis in Burmese pythons (Python molurus) by demonstrating that females use their own body temperature to modulate thermogenesis. Although pythons are commonly cited as thermogenic, the actual extent of thermogenesis within the family Pythonidae is unknown. Thus, I assessed the thermogenic capability of five previously unstudied species of python to aid in understanding phylogenetic, morphological, and distributional influences on thermogenesis in pythons. Results suggest that facultative thermogenesis is likely rare among pythons. To understand why it is rare, I used an artificial model to demonstrate that energetic costs to the female likely outweigh thermal benefits to the clutch in species that do not inhabit cooler latitudes or lack large energy reserves. In combination with other studies, these results show that facultative thermogenesis during brooding in pythons likely requires particular ecological and physiological factors for its evolution.
ContributorsBrashears, Jake (Author) / DeNardo, Dale (Thesis advisor) / Harrison, Jon (Committee member) / Deviche, Pierre (Committee member) / McGraw, Kevin (Committee member) / Smith, Andrew (Committee member) / Arizona State University (Publisher)
Created2012
Description
The Great Bustard (Otis tarda) is an iconic species of the temperate grasslands of Europe and Asia, a habitat that is among the least protected ecosystems in the world. A distinct subspecies, the Asian Great Bustard (O. t. dybowskii), is poorly understood due to its wary nature and remote range in Siberia, Mongolia, and northern China. This subspecies is now endangered by rapid development.
Using satellite telemetry and remote sensing, I investigated three aspects of the Asian Great Bustard’s ecology critical to its conservation: migratory routes, migratory cues, and habitat use patterns. I found that Asian Great Bustards spent one-third of the year on a 2000 km migratory pathway, a distance twice as far as has previously been recorded for the species. Tracked individuals moved nomadically over large winter territories and did not repeat migratory stopovers, complicating conservation planning. Migratory timing was variable and migratory movements were significantly correlated with weather cues. Specifically, bustards migrated on days when wind support was favorable and temperature presaged warmer temperatures on the breeding grounds (spring) or advancing winter weather (fall). On the breeding grounds, Asian Great Bustards used both steppe and wheat agriculture habitat. All recorded reproductive attempts failed, regardless of habitat in which the nest was placed. Agricultural practices are likely to intensify in the coming decade, which would present further challenges to reproduction. The distinct migratory behavior and habitat use patterns of the Asian Great Bustard are likely adaptations to the climate and ecology of Inner Asia and underscore the importance of conserving these unique populations.
My research indicates that conservation of the Asian Great Bustard will require a landscape-level approach. This approach should incorporate measures at the breeding grounds to raise reproductive success, alongside actions on the migratory pathway to ensure appropriate habitat and reduce adult mortality. To secure international cooperation, I proposed that an increased level of protection should be directed toward the Great Bustard under the Convention on Migratory Species (CMS). That proposal, accepted by the Eleventh Conference of Parties to CMS, provides recommendations for conservation action and illustrates the transdisciplinary approach I have taken in this research.
Using satellite telemetry and remote sensing, I investigated three aspects of the Asian Great Bustard’s ecology critical to its conservation: migratory routes, migratory cues, and habitat use patterns. I found that Asian Great Bustards spent one-third of the year on a 2000 km migratory pathway, a distance twice as far as has previously been recorded for the species. Tracked individuals moved nomadically over large winter territories and did not repeat migratory stopovers, complicating conservation planning. Migratory timing was variable and migratory movements were significantly correlated with weather cues. Specifically, bustards migrated on days when wind support was favorable and temperature presaged warmer temperatures on the breeding grounds (spring) or advancing winter weather (fall). On the breeding grounds, Asian Great Bustards used both steppe and wheat agriculture habitat. All recorded reproductive attempts failed, regardless of habitat in which the nest was placed. Agricultural practices are likely to intensify in the coming decade, which would present further challenges to reproduction. The distinct migratory behavior and habitat use patterns of the Asian Great Bustard are likely adaptations to the climate and ecology of Inner Asia and underscore the importance of conserving these unique populations.
My research indicates that conservation of the Asian Great Bustard will require a landscape-level approach. This approach should incorporate measures at the breeding grounds to raise reproductive success, alongside actions on the migratory pathway to ensure appropriate habitat and reduce adult mortality. To secure international cooperation, I proposed that an increased level of protection should be directed toward the Great Bustard under the Convention on Migratory Species (CMS). That proposal, accepted by the Eleventh Conference of Parties to CMS, provides recommendations for conservation action and illustrates the transdisciplinary approach I have taken in this research.
ContributorsKessler, Aimee (Author) / Smith, Andrew T. (Thesis advisor) / Brown, David (Committee member) / Franklin, Janet (Committee member) / McGraw, Kevin (Committee member) / Wu, Jianguo (Committee member) / Arizona State University (Publisher)
Created2015
Description
This 15-week long course is designed to introduce students, specifically in Arizona, to basic sustainability and conservation principles in the context of local reptile wildlife. Throughout the course, the students work on identifying the problem, creating visions for the desired future, and finally developing a strategy to help with reptile species survival in the valley. Research shows that animals in the classroom have led to improved academic success for students. Thus, through creating this course I was able to combine conservation and sustainability curriculum with real-life animals whose survival is directly being affected in the valley. My hope is that this course will help students identify a newfound passion and call to action to protect native wildlife. The more awareness and actionable knowledge which can be brought to students in Arizona about challenges to species survival the more likely we are to see a change in the future and a stronger sense of urgency for protecting wildlife. In order to accomplish these goals, the curriculum was developed to begin with basic concepts of species needs such as food and shelter and basic principles of sustainability. As the course progresses the students analyze current challenges reptile wildlife faces, like urban sprawl, and explore options to address these challenges. The course concludes with a pilot pitch where students present their solution projects to the school.
ContributorsGoethe, Emma Rae (Author) / Brundiers, Katja (Thesis director) / Bouges, Olivia (Committee member) / School of Sustainability (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Invasive plants harm the ecological properties of natural systems, human health,
and local economies. However, the negative impacts of invasive species are not always
immediately visible and may be disregarded by local communities if social benefits of
control efforts are not clear. In this dissertation, I use a mixed-methods approach to
investigate the drivers of invasive plant distribution, potential financially feasible
management techniques to control invasion, and community forest user perceptions of
those techniques. In this work, I aim to incorporate the diverse perspectives of local
people and increase the long-term success of invasive species control activities in socio
economically vulnerable populations.
Integrating a spatially and temporally diverse data set, I explore the social and
ecological drivers of invasive plant abundance across 21 buffer zone community forests
in the Western Chitwan Valley of Nepal. I evaluate to what extent forest user and
collective manager activities, the legacies of historic activities, and ecological properties
influence present-day invasive plant abundance. I built upon this study to identify areas
with critically high levels of invasion then initiated a three-year, community-based
management intervention to evaluate traditional and adaptive land management
approaches to control invasive plants. I found that both approaches reduced invasive
plant abundance relative to the surrounding, untreated forest. I then interviewed focus
groups to investigate their perceived efficacy of the various treatment types and found
that almost all forest users and managers preferred the adaptive approach over the
traditional management approach. Notably, forest users cited the importance of the
availability of forest resources and lack of harmful plants in the plots that had undergone
this method. Understanding how forest users relate to and experience invasive plants has
been relatively understudied but can influence forest user engagement in different
management approaches. For this reason, I performed in-depth ethnoecological
interviews to explore how forest users perceive, how they utilize, and to what extent they
value invasive plants. This mixed-methods approach contributes to a more holistic
understanding of the role that local people play in invasive plant management and
restoration activities.
and local economies. However, the negative impacts of invasive species are not always
immediately visible and may be disregarded by local communities if social benefits of
control efforts are not clear. In this dissertation, I use a mixed-methods approach to
investigate the drivers of invasive plant distribution, potential financially feasible
management techniques to control invasion, and community forest user perceptions of
those techniques. In this work, I aim to incorporate the diverse perspectives of local
people and increase the long-term success of invasive species control activities in socio
economically vulnerable populations.
Integrating a spatially and temporally diverse data set, I explore the social and
ecological drivers of invasive plant abundance across 21 buffer zone community forests
in the Western Chitwan Valley of Nepal. I evaluate to what extent forest user and
collective manager activities, the legacies of historic activities, and ecological properties
influence present-day invasive plant abundance. I built upon this study to identify areas
with critically high levels of invasion then initiated a three-year, community-based
management intervention to evaluate traditional and adaptive land management
approaches to control invasive plants. I found that both approaches reduced invasive
plant abundance relative to the surrounding, untreated forest. I then interviewed focus
groups to investigate their perceived efficacy of the various treatment types and found
that almost all forest users and managers preferred the adaptive approach over the
traditional management approach. Notably, forest users cited the importance of the
availability of forest resources and lack of harmful plants in the plots that had undergone
this method. Understanding how forest users relate to and experience invasive plants has
been relatively understudied but can influence forest user engagement in different
management approaches. For this reason, I performed in-depth ethnoecological
interviews to explore how forest users perceive, how they utilize, and to what extent they
value invasive plants. This mixed-methods approach contributes to a more holistic
understanding of the role that local people play in invasive plant management and
restoration activities.
ContributorsClark, Michele Diane (Author) / Hall, Sharon J. (Thesis advisor) / Shrestha, Milan (Committee member) / Yabiku, Scott (Committee member) / Budruk, Megha (Committee member) / Arizona State University (Publisher)
Created2020
ContributorsMorgan, Marshall (Author, Co-author) / Shrestha, Milan (Thesis director) / Boyce-Jacino, Katherine (Committee member) / Barrett, The Honors College (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor)
Created2021-12
ContributorsMorgan, Marshall (Author, Co-author) / Shrestha, Milan (Thesis director) / Boyce-Jacino, Katherine (Committee member) / Barrett, The Honors College (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor)
Created2021-12
Description
Located directly south of Pima County, Arizona, there is a culturally rich community known as Santa Cruz County, Arizona. Santa Cruz County is a smaller community being home to an estimated 47,000 people. Santa Cruz County has a rich history given its proximity to the United States-Mexico border. One example of this rich history can be found at the Tumacacori National Historical Park (NHP) with the attractive and unique ruins. The Tumacacori NHP was once an active Spanish mission that oversaw the religious expansion and communal resources. While the Tumacacori NHP no longer operates in this manner, it does serve an important role in providing visitors with a diverse and immersive look into the history of the region and the Tumacacori mission. While the Tumacacori NHP is meant to be a place for all people to visit, most visitors are not from the local community. The reason for this stems from a lack of educational and engagement opportunities between the Tumacacori NHP and the community youth, mainly due to community members being unaware of the park’s existence or the programs that are offered. This project analyzes and uncovers this disconnect as well as the barriers between the Tumacacori NHP and the Santa Cruz County youth through a research study and the use of children’s literature.
ContributorsMorgan, Marshall (Author) / Shrestha, Milan (Thesis director) / Boyce-Jacino, Katherine (Committee member) / Barrett, The Honors College (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor) / School of Community Resources and Development (Contributor) / School of Sustainability (Contributor)
Created2021-12