Ecology and Evolutionary Biology Commons^™

The Evolution Of Dragons, Laura J. Mayfield

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Dragons have been depicted in human art as early as 4500 BCE. For centuries, these fantasy creatures have inspired countless folk and fantasy tales, as well as appearing in the art of different cultures around the world. Now there are thousands of different depictions of these huge, flying, fire-breathing lizards, but are any of them possible? In this study, I reference peer-reviewed scientific articles, phylogenetic analysis, and paleoart studies to create biologically-sound dragons. Basing the dragon lineage on a real branch of webbed-winged scansoriopterygids—an extinct family of climbing and gliding maniraptoran dinosaurs—I explored the possible wing-structure, fire-breathing abilities, and effects …

Leaf Choice By Salmonfly Nymphs (Pteronarcys Californica) In Western Montana, Emily L. Hamant, Art Woods, James Frakes

Undergraduate Theses, Professional Papers, and Capstone Artifacts

No abstract provided.

Influence Of Livestock And Electrified Fences On Livestock Depredation And Habitat Selection By Grizzly Bears In The Mission Valley, Montana, Kari Lynn Eneas

Graduate Student Theses, Dissertations, & Professional Papers

Balancing protection between livestock and carnivores has been a long-standing challenge in conservation. When encounters between carnivores and livestock or humans result in conflict or livestock depredation, the safety of both wildlife and humans are at risk. Reducing livestock depredation by grizzly bears (Ursus arctos horribilis) will be important as populations continue to recover and expand beyond public lands in the Northern Continental Divide Ecosystem. We used GPS locations from 8 female grizzly bears spanning 5 years in the Mission Valley, Montana, to evaluate the effect of livestock on habitat selection of grizzly bears. The Mission Valley is located on …

Bottom-Up Herbivore-Plant Feedbacks Trump Trophic Cascades In A Wolf-Elk-Grassland System, Trevor C. Weeks

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Top-down predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. While these effects have been extensively studied in aquatic environments, fewer studies have examined trophic cascades in terrestrial ecosystems. And fewer still terrestrial studies have tested for trophic cascades between vertebrates and grassland vegetation. Across the globe, grassland plant biomass is driven by both precipitation and non-linear positive feedbacks between grazing and plant productivity, as predicted by the Intermediate Grazing Hypothesis. Yet little is known about the role that apex carnivores …

Selection Of Forage And Avoidance Of Predation Risk By Partially Migratory Mule Deer, Collin Jeffrey Peterson

Graduate Student Theses, Dissertations, & Professional Papers

Migration by ungulates has traditionally been thought of as a strategy that increases access to forage quality or reduces exposure to risk of predation, but the benefits of migration may be waning globally. In partially migratory populations, the persistence of both migrant and resident strategies is an intriguing ecological phenomenon, because migrants and residents often face contrasting fitness consequences. Partial migration is common in mule deer (Odocoileus hemionus), a species that has experienced widespread declines across the western United States during recent decades. Mule deer seldom switch between migratory strategies throughout their lifetime, which may make them less resilient to …

Comparing Fence Modeling And Mapping Approaches To Support Wildlife Management And Research In Southwest Montana, Simon Albert Buzzard

Graduate Student Theses, Dissertations, & Professional Papers

Fences pose significant challenges to wildlife movement, but their effects are difficult to quantify because fence location and fence type data are lacking on a global scale. We developed a fence location and density model in southwest Montana, USA to provide data to researchers and managers, and test whether previous models could be applied to a new region and retain suitable levels of statistical accuracy. Our model used local expert opinion to inform how road, land cover, and ownership spatial layers interacted to predict fence locations. We validated the model against fence data collected on random 3.2 km road transects …

Resource Selection And Calving Success Of Moose In Colorado, Forest P. Hayes

Graduate Student Theses, Dissertations, & Professional Papers

Across much of North America, moose populations (Alces alces) are declining due to disease, predation, climate, and anthropogenic pressures. Despite this, populations of moose in Colorado have continued to grow. Studying successful (i.e., persistent or growing) populations of moose can facilitate the continued conservation of the species by identifying habitat features critical for moose persistence.

First, I evaluated calving success of moose in Colorado and the impact of willow habitat quality and nutrition. I then estimated the probability of female moose having a calf using repeated observations in a Bayesian occupancy model. I assigned values for dry matter …

Protecting Biodiversity On National Forests: The Evolution And Implementation Of Forest Planning Regulations, Anna Wearn

Graduate Student Theses, Dissertations, & Professional Papers

In 2012, the U.S. Forest Service (USFS) promulgated new forest planning regulations that significantly altered national forest management. One of the most controversial and important advancements was the inclusion of what were meant to be stronger biodiversity protections. An analysis of USFS’s rationale in revising the biodiversity regulations provides insights into how to interpret the substantively and procedurally new ecosystem and species protections. Examining this regulatory history reveals three key changes to the manner in which national forests are required to manage and monitor biodiversity: 1) a greater reliance on science to inform planning, 2) a new emphasis on ecological …

Food Web Effects Of Lake Trout (Salvelinus Namaycush) Invasion In Northwestern Montana, Charles Wainright

Graduate Student Theses, Dissertations, & Professional Papers

Around the turn of the 20th century, lake trout (Salvelinus namaycush) were widely introduced in several lakes and reservoirs outside their native range in western North America. Since then, lake trout have become problematic in many lakes where they were introduced, causing significant declines in popular sport fishes and native species, most notably federally protected bull trout (Salvelinus confluentus). Despite evidence that invasive fish can cause cascading trophic effects in aquatic communities, the impacts of lake trout introduction / invasion on aquatic food webs remain poorly understood. Moreover, native fish restoration programs tend to focus on suppression …

Finding Fishers: Determining The Distribution Of A Rare Forest Mesocarnivore In The Northern Rocky Mountains, Jessica M. Krohner

Graduate Student Theses, Dissertations, & Professional Papers

The Northern Rocky Mountain fisher population (Pekania pennanti), is classified as a Species of Greatest Conservation Need and is of special concern to state, federal, and tribal entities. In this thesis, we present methods to effectively survey fishers across the northern Rockies of Idaho and Montana, and provide estimates of fisher distribution at a population range-wide scale through occupancy analyses. We also assess factors that influence fisher occurrence through covariate analyses and identify core fisher habitat in the northern Rockies through spatial occupancy modeling. By sampling broadly across the landscape, we provide baseline distributional data for comparison against …

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 …

Decoupled Diel Solutes: Linking Primary Production And Nitrate Uptake In A Montane Stream, Kimberly Bray

Graduate Student Theses, Dissertations, & Professional Papers

Tight coupling of surface water diel dissolved oxygen (DO) and nitrate-N (NO₃-N) signals reflects stoichiometric demand of carbon and nitrogen in stream ecosystems. However, DO and NO₃-N can become decoupled due to alternative drivers of diel solutes, resulting in conflicting estimates of stoichiometric and modeled NO₃-N uptake. In this study, I measured benthic biomass, hydrology, and dissolved solutes in a montane stream located in western MT over a growing season (June-October 2019). Daily stream metabolism and NO₃-N uptake were modeled using a single-station open-channel approach. Timing and amplitude of key diel signals …

Golden Eagle Resource Selection And Environmental Drivers Of Reproduction In The Northern Range Of Yellowstone National Park, David Brown Haines

Graduate Student Theses, Dissertations, & Professional Papers

In the United States (US), National Parks are considered the “crown jewels” of protected lands. However, the importance of National Parks to wildlife populations and the species that inhabit them is not often quantified, thus, requiring a better understanding of National Parks as a conservation tool. Golden eagles (Aquila chrysaetos) are a North American species of conservation concern and territories in the northern range of Yellowstone National Park (YNP) are relatively dense. However, average reproductive rates over the past ten years (2011-2020) have been low (productivity = 0.34, nest success = 28%). The contrast of high density and …