Life Sciences Commons^™

Heat For The Masses: Thermal Ecology Of The Western Tent Caterpillar, Victoria Dahlhoff

Graduate Student Theses, Dissertations, & Professional Papers

A unique feature of some gregarious, colonial insects is their ability to create external structures that alter environmental conditions for the entire (often family) group. A combination of physical alteration of local microhabitats and behavioral thermoregulation allows many of these animals to actively control their body temperatures, which allows them to regulate energy use and metabolism in variable thermal environments. Here I describe mechanisms of microhabitat modification and thermal regulation in the western tent caterpillar, Malacosoma californicum pluviale. Tent caterpillars build communal silk tents, whose temperatures can rise substantially above ambient air temperature. I experimentally manipulated colony sizes and examined …

Metabolic And Cardiovascular Marker Alterations During Critical Training In Wildland Firefighters, Shae Gurney

Graduate Student Theses, Dissertations, & Professional Papers

Introduction: Wildland firefighters (WLFFs) are confronted with numerous physical and mental stressors. Pre-fire season includes an intense 2-week critical training (CT) period; a preparatory phase of multiple activities that can result in injury, illness, and rhabdomyolysis. The purpose of this study was to identify physiologic changes in metabolic, inflammatory, and oxidative stress biomarkers during 2 weeks of CT in WLFFs.

Methods: Eighteen male (29.4 ± 1.1 yr, 182.1 ± 1.6 cm) and three female (26.7  2.6 yr, 169.5  4.2 cm) participants were recruited from a Type I interagency hotshot crew and monitored over their 2-week CT. Fitness was …

Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee

Graduate Student Theses, Dissertations, & Professional Papers

Long-term viability of endangered populations requires development of effective management strategies that target the population vital rate with the highest potential to influence population trajectories. When adult survival is high and stable, juvenile recruitment is the vital rate with the greatest potential to improve population trajectories. For my thesis I examined how lactating Sierra Nevada Bighorn sheep (Ovis Canadensis sierra) balance forage and predation risk during the neonatal period. I first identified resource selection strategies employed by lactating females to promote survival of neonates and then determined the primary factors affecting survival of neonates. I found lactating females selected for …

Molecular Diversity Of Foliar Fungal Endophytes In Relation To Defense Strategies And Disease In Whitebark Pine, Lorinda Bullington

Graduate Student Theses, Dissertations, & Professional Papers

An invasive fungal pathogen, Cronartium ribicola (the causative agent of white pine blister rust) infects and kills whitebark pine (Pinus albicaulis) throughout the western US. Blister rust has decreased whitebark pine populations by over 90% in some areas. Whitebark pine, a keystone species, has been proposed for listing under the Endangered Species Act in the U.S., and the loss of this conifer is predicted to have severe impacts on forest composition and function in high elevations. Hundreds of asymptomatic fungal species live inside whitebark pine tissue, and recent studies suggest that these fungi can influence the frequency and …

Integrated Stress And Community Perceptions: Toward An Understanding Of Human-Cougar Tolerance, Lara Brenner

Graduate Student Theses, Dissertations, & Professional Papers

Evidence suggests that cougars (Puma concolor) are beginning to recolonize their traditional range in the Midwestern and Eastern US, returning to a landscape and a social environment that have changed drastically in a century of absence. Any hope of the cougar’s persistence depends on both human tolerance of their presence and on cougar tolerance of disrupted habitat. In this thesis, we took advantage of diverse cougar policy in place in the Western US to explore variation in human attitudes and acceptability of cougars and in the cougar stress response. We validated a process to identify and extract cortisol …

Population Differentiation And Habitat Selection Of A Montane Red Fox Population In The Greater Yellowstone Ecosystem, Patrick Cross

Graduate Student Theses, Dissertations, & Professional Papers

Montane red fox (Vulpes vulpes) populations across the western United States are genetically and morphologically distinct from foxes at lower elevations. These montane populations also share a preference for subalpine forest habitats. One hypothesis is that they stem from boreal forest-associated ancestors that expanded during the Pleistocene when boreal forests extended farther south than they do today. Forest habitat selection may therefore aid the persistence of native populations surrounded by non-native conspecifics. Alternatively, this behavior may be an avoidance mechanism in response to competition with larger coyotes (Canis latrans), or a product of the fox's natural adaptability. The red fox …

Arbuscular Mycorrhizal Fungi: Factors Affecting Soil Organic Matter Storage, Carl Lee Rosier

Graduate Student Theses, Dissertations, & Professional Papers

Arbuscular mycorrhizal fungi (AMF) are soil fungi forming symbiotic associations with majority of land plants. AMF alter soil organic matter (SOM) directly through stabilization of soil aggregates and indirectly providing a path in which plant fixed C02 is transferred below-ground. Understanding contributions of AMF to SOM via protein production and stabilization of soil aggregates will greatly aid our understanding of soil carbon sequestration, nutrient cycling and mitigation of soil erosion. The work presented in chapter 2 challenges the glomalin extraction process and assesses the accuracy of the Bradford and monoclonal-antibody ELISA detection methods. My results clarify the contribution of glomalin …