Ecology and Evolutionary Biology Commons^™

Estimation Of Probability Of Habitat Use Of Roosevelt Elk On The Olympic Peninsula, Vincent Michael Gugliotti

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Estimating the probability of habitat use for a particular species is crucial to the direct management and conservation of that species. Without knowledge of habitat preferences, managers cannot effectively focus efforts on vital resources or landscape types. However, modelling probability of habitat use can be done in several ways which leaves room for variation and uncertainty in the estimates produced by each method. This study is an examination of the variation between two estimates of probability of habitat use while focusing on a particular subspecies of elk that inhabits a unique ecosystem relative to other elk subspecies. I modeled elk …

Out Of The Frying Pan And Into The Fire: How Hunting Affects The Diel Activity Patterns Of Ungulates In Lubrecht Experimental Forest, Shawn M. Parsons

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Predator-prey dynamics shape diel activity patterns of large mammals. The avoidance of predation risk by prey in both space and time can affect predator-prey overlap and reduce risk of mortality. Here, I examined if rifle hunting affected the diel activity patterns of ungulates and their primary predator, pumas, in Lubrecht Experimental Forest, Montana. I deployed 30 infrared wildlife remote cameras across 29 sites using a stratified random design over three months before, during, and after the Fall 2022 Montana rifle hunting season. This project was also part of the Snapshot USA 2022 initiative. Using timestamps from these photos, daily activity …

The Links To Cancer: How Golf Became Dangerous And What We Can Do To Save The Game, Meredith Boos

Undergraduate Theses, Professional Papers, and Capstone Artifacts

This study is a comprehensive meta-analysis on health claims linked to exposure to golf courses, more specifically the chemicals used to maintain their appearance. It provides a brief history of the golf industry and how its growth exacerbated the environmental impact as well as an explanation of the legal landscape that will affect golf course management. Golf courses can disrupt local ecologies, contaminate ground water, rivers, lakes and streams with run-off, and be responsible for the bioaccumulation of chemicals which remain dangerous for decades. Despite the adverse effects of golf courses on the environment, there remains an opportunity to transform …

Assessing The Efficacy Of Beaver Dam Analogs In Willow Restoration, Hannah Hill, Dylan Ritter

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Willow establishment is a necessary objective of stream restoration due to their role in bank stabilization, stream shading, and enhancement of biodiversity across the riparian zone. However, anecdotal observation indicated that establishment on beaver dam analogue (BDA) restored streams may be lacking. BDA’s mimic the pooling effects of natural beaver structures and are intended to help recreate historic conditions that existed before beaver extirpation. When working as intended, ecosystem function is restored, and a major aspect of this is willow presence. Because of these observations, as well as limited information on willow recruitment following restoration, we ask the following questions. …

Predicting Mountain Lion Resource Selection And Abundance In North America, William Connor O'Malley

Graduate Student Theses, Dissertations, & Professional Papers

The relationship between habitat quality and density is well documented in lower trophic levels but to what extent it can be extended to higher trophic levels is unknown. I tested the relationship between habitat quality, home-range size and density using a wide-ranging, well-studied, top carnivore, the mountain lion (Puma concolor). First, I created a second-order resource selection function (RSF) for mountain lions in their current North American range using GPS collar data from 476 individuals in 20 study sites and remotely-sensed landscape data. I used the RSF and home range estimates derived from collared animals to quantify mountain …

Individual And Population Responses To Hydrologic Variability In A Headwater Stream Salamander, Madaline Cochrane

Graduate Student Theses, Dissertations, & Professional Papers

Understanding how organisms respond to environmental variability is a central goal in ecology – a goal made even more pressing by the herculean challenge global climate change presents to all organisms. Climate change is increasing the frequency and intensity of floods and droughts, which will likely have disproportionate effects on freshwater organisms. Many stream-associated species have multi-stage life histories. However, we lack an empirical understanding of life history and movement responses of these organisms to hydrologic disturbances, and how these responses may influence demographic rates. In my dissertation, I used a combination of growth, developmental, movement, and demographic data to …

How Aquatic Insects Mitigate Temperature-Oxygen Challenges Via Behavioral, Morphological, And Physiological Plasticity, Jackson H. Birrell

Graduate Student Theses, Dissertations, & Professional Papers

How do organisms respond to environmental challenges and to environmental change? These questions occupy a central place in ecology and answering them will help us to understand why species live where they do, how organisms are affected by human activities, and, ultimately, how to choose among alternative conservation strategies. These questions are difficult, however, for two reasons. First, environmental challenges often involve multiple, interacting stressors. Second, individual responses can be modified by behavioral, morphological, and physiological plasticity. My dissertation investigates how interactions between temperature and oxygen influence the performance and survival of aquatic insects and how plasticity allows individuals to …

Evaluating The Relative Influence Of Soil Water Potential, Soil Moisture, And Vapor Pressure Deficit On Semi-Arid Vegetation Dynamics, Kayla R. Jamerson

Graduate Student Theses, Dissertations, & Professional Papers

Knowledge of vegetation’s response to soil water availability and atmospheric demand is critical to understanding the impact of climate change on semi-arid ecosystems. However, limited field-based research has been conducted to assess the relative importance of these drivers and previous research has simplified the assessment of soil water availability by relying on soil volumetric water content (VWC) as a primary control on plant growth, which, as opposed to soil water potential (Ψsoil), does not account for the effects of soil texture on plant available water. To address these gaps, we compared remotely sensed indicators of vegetation response to field based …

Invasive Earthworms In The Crown Of The Continent System And Implications For Land Management, Meghan Elizabeth Scott

Graduate Student Theses, Dissertations, & Professional Papers

The United States contains invasive earthworms originating from Europe and Asia; the majority are European lumbricids. Direct introduction occurs primarily through human activity and, once established, earthworm populations are difficult to address. When exotic earthworms engage in bioturbation, they negatively alter subterranean food webs and nutrient cycling by disrupting soil layering systems. The most prominent form of physical alteration is the change and removal of the topmost organic layer. This disruption is associated with altered nitrogen and carbon cycling, as well as altered forest floor plant communities.

The Crown of the Continent ecosystem is located in southwestern Alberta, southeastern British …

Understanding Caribou Population Cycles, Jack R. St. John

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The complex population dynamics of caribou (Rangifer tarandus) were studied to determine the patterns of their population cycles and the processes driving them. It is well established, via previous archaeological research and Indigenous knowledge, that large migrating caribou herds found in and around the tundra at northern latitudes experience population boom and busts roughly every several decades. However, the processes driving the dynamics of these cycles are relatively unknown, which makes managing caribou herds for recreational and subsistence harvests difficult. It has been hypothesized that a combination of intrinsic and extrinsic factors shape these cycles, with density-dependence, predation, …

The Expansion Of Shrimp Farms In The Gulf Of California And Potential For Restoration To Support Migratory Waterbirds, Miles Scheuering

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Wintering and stopover areas provide crucial habitat for migratory birds yet are often understudied. The estuaries of Sonora and Sinaloa on the Gulf of California in Mexico provide critical wintering and stopover sites for migratory waterbirds in the Pacific Flyway. Shrimp farms are the greatest threat to these areas and their full impact is not well understood but they provide poor habitat for waterbirds. A significant portion of existing farms may be abandoned based on a disparity between active area reported by the Sonora and Sinaloa state commissions and observed area based on remote sensing. Abandoned farms represent potential area …

Impact Of Arbuscular Mycorrhizal Fungi On Conyza Canadensis Drought Responses And Possible Mechanisms, Kian G.M. Speck, Ylva Lekberg, Anna Sala

Undergraduate Theses, Professional Papers, and Capstone Artifacts

• Arbuscular mycorrhizal fungi (AMF) are important plant mutualists that can facilitate plant responses to various environmental stressors, such as drought. A plant that may benefit from AMF-induced drought tolerance is Conyza canadensis due to its ability to thrive in dry conditions and its high colonization rate. However, no studies have researched C. canadensis in this context and the exact mechanisms of AMF-induced drought tolerance are still unknown.
• To better understand if and how AMF facilitate drought response in C. canadensis, we conducted a greenhouse experiment comparing the response of mycorrhizal and non-mycorrhizal plants to three watering levels. We measured …

Analyzing Interactions Among Migratory Elk And Semi-Permeable Fences Amongst A Highly Fragmented Landscape On The Blackfeet Reservation, Landon J. Magee

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Large scale fences pose a threat to ungulate movement on the Blackfeet Reservation. Since the beginning of the last decade, the Blackfeet Reservation has experienced intense habitat fragmentation in the northern regions of the reservation, particularly in prime elk habitat that is believed to be along a migration corridor. One source of fragmentation has been the erection of a semi-permeable fence associated with a large bison ranch. The purpose of this study was to preliminarily assess potential interactions of elk (Cervus canadensis) and the semi-permeable bison fence as a precursor for further study. I worked in collaboration with …

Monitoring The Wetland Landscape: White-Faced Ibis (Plegadis Chihi) Breeding Habitat As A Model Assemblage, Shea P. Coons

Graduate Student Theses, Dissertations, & Professional Papers

Wetlands structure landscape biodiversity by providing critical habitat to numerous fish and wildlife species. However, climate change, growing human populations, and shifting land use practices strain limited water supplies that sustain wetlands in the semi-arid western US. Conserving a wetland network with prominent value to wildlife is paramount to ensure future security of habitat and ecosystem processes. Here, I use white-faced ibis (Plegadis chihi; hereafter ‘ibis’) breeding colonies as a model system to identify and monitor a landscape-scale wetland network across the semi-arid western US. Ibis serve an important role in marking ecologically important wetland networks because they require a …

Management And Conservation Of Westslope Cutthroat Trout In An Impacted, Connected River System, Troy Weant Smith

Graduate Student Theses, Dissertations, & Professional Papers

Westslope cutthroat trout Oncorhynchus clarkii lewisi (WCT) is a native species of high conservation value that historically exhibited partially migratory behavior throughout its range. Long-term persistence of WCT is threatened by human habitat modification, fragmentation, introduction of non-native species, and hybridization. As a result of these changes, remnant populations in Montana have shifted toward resident populations in headwater systems and away from migratory populations in larger connected river networks. This is compounded by the historic introduction of rainbow trout O. mykiss (RBT) that hybridize with WCT, especially in larger river habitats. Rock Creek in western Montana, USA was historically managed …

Concentration And Composition Of Nanoparticles And Colloidal Particles In A Mine-Waste Contaminated River, Kaitlin Rose Perkins

Graduate Student Theses, Dissertations, & Professional Papers

Metals and metalloids (metal(loid)s) in aquatic ecosystems are often described through measures of their concentrations in whole and filtered waters. The filtered fraction is operationally defined as “dissolved,” and assumed to be primarily composed of free metal(loid) ions or of ions bound by low molecular weight organic matter. This definition ignores that the dissolved fraction also likely contains colloidal particles (1 to 1000 nm) that can pass through commonly used filters. This colloidal fraction can also be preferentially removed from the water column by algae and other aquatic organisms compared to free metal(loid) ions and organic bound metal(loid)s. Though they …

Nitrogen Dynamics And Transport Along Flowpaths In A Rural Wetland-Stream Complex, Colton Kyro

Graduate Student Theses, Dissertations, & Professional Papers

Human activities have doubled the rate of nitrogen inputs onto the landscape resulting in elevated nitrogen concentrations in our streams. Anthropogenically applied nitrogen is largely transported to stream networks via groundwater movement. Groundwater discharge occurs in distinct points along a stream but whose influences can often persist far beyond that area due to insufficient biogeochemical removal of imported nitrogen potentially causing alterations in community structure and precipitating large algae blooms. To understand the factors governing nitrogen abundance in a historical polluted stream, I used a mass-balance approach to quantify groundwater-surface water interaction and the magnitude of groundwater nitrogen input and …

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 …

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 …

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 …

Tiger Monitoring In Bhutan Using Non-Invasive Genetic Tools, Tashi Dhendup

Graduate Student Theses, Dissertations, & Professional Papers

Large carnivores are one of the most threatened group of animals in the world. They suffer from prey depletion, persecution by humans, and habitat loss and fragmentation which are extensively driven by anthropogenic activities. One such species is the tiger Panthera tigris. Tigers are found in thirteen countries in Asia and are protected across the range; however, tiger numbers have declined as an after effect of habitat loss, prey depletion and poaching. Human-induced changes have reduced the tiger's historical range to about 7% in which a little more than 3900 tigers are found. Most of these individuals currently exist …

Population And Breeding Ecology Of Sagebrush Steppe Songbirds, Kayla Ann Ruth

Graduate Student Theses, Dissertations, & Professional Papers

Sagebrush steppe is one of the most threatened ecosystems in North America. Domestic livestock grazing is the dominant land use of sagebrush steppe across the west. Rest-rotation grazing systems can be a conservation management tool, most recently, by the Natural Resource Conservation Service - Sage Grouse Initiative (SGI). The goal of SGI is to encourage private landowners to use a livestock grazing regime that maintains or improves habitat for greater sage-grouse (Centrocercus urophasianus), as well as improve rangeland productivity. Songbirds are biological indicators that can assess the health of sagebrush steppe. Avian adult density estimates are often used …

Colloidal And Truly Dissolved Metal(Loid)S In Wastewater Lagoons And Their Removal With Floating Treatment Wetlands, Lauren Sullivan

Graduate Student Theses, Dissertations, & Professional Papers

Climate change is predicted to cause continuing declines in late-season streamflow, thus increasing the relative contribution of wastewater effluent to surface water flows. Wastewater effluent represents a critical point source of metal and metalloid contamination to aquatic ecosystems and wastewater lagoons are the most common wastewater treatment system in the rural United States. Although the fraction of total wastewater metals and metalloids in "dissolved" forms (defined here asnm) likely drives the potential for negative effects on receiving waters, this broad operational definition lumps truly dissolved solutes (nm) with small colloids and nanomaterials (1-450 nm; hereafter colloids). This size distinction may …

Avian Community Responses To Bison Grazing In North American Intermountain Grasslands, Danielle A. Fagre

Graduate Student Theses, Dissertations, & Professional Papers

Grassland and shrubland songbird species are a guild of conservation concern in North America. Many of these species have experienced severe population declines, due to habitat loss and land use change. This makes the conservation and management of remaining habitat of crucial importance for this guild. Grazing by large herbivores is an ecosystem process in grassland systems, and in North America, one of the major historic grazers was the Plains bison (Bison bison). Bison are considered ecosystem engineers, because they modify habitat to be more or less suitable for other species, such as grassland and shrubland songbirds. Bison …

Camera Traps In Wildlife Research: Through My Lens, Bryson P. Allen

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Wildlife species can be difficult to study because they can have very large ranges and can be wary of observers. Researchers have been using camera traps in recent decades as a way to study wildlife behavior and population metrics. Here I explore the history of these tools in wildlife biology, their possible applications, and limitations.

Bottom-Up And Top-Down Controls On Food Webs In Headwater Streams, Miriam O. Bayer

Graduate Student Theses, Dissertations, & Professional Papers

Headwater streams account for 70% of stream channel length in the USA and are important as hotspots of nutrient uptake and native biodiversity. Biofilm, the mixed auto- and heterotrophic microbial community covering stream substrates, is where the majority of nutrient processing occurs, and forms the base of stream food webs, particularly in heavily shaded, oligotrophic streams. Both bottom-up (e.g., nutrients, light) and top-down (i.e., consumption) processes are known to affect periphyton, the autotrophic component of biofilm, but little is known about what controls the biofilm community as a whole. Top-down effects are common in streams, where fish are often the …

Understanding Patterns And Drivers Of Alaskan Fire-Regime Variability Across Spatial And Temporal Scales, Tyler J. Hoecker

Graduate Student Theses, Dissertations, & Professional Papers

Boreal forest and tundra ecosystems are globally important because the mobilization of large carbon stocks, and changes in energy balance could act as positive feedbacks to ongoing climate warming. In Alaska, wildfire is a key driver of ecosystem structure and function, and therefore fire strongly determines the feedbacks between high-latitude ecosystems and the larger Earth system. The paleoecological record from Alaska reveals the sensitivity of fire regimes to climatic and vegetation change over centennial to millennial time scales, highlighting increased burning with warming and/or increased landscape flammability associated with large-scale vegetation changes. This thesis focuses on two studies aimed at …