Index Catalog // ScholarsArchive@OSU

Population Differentiation in two Northeastern Pacific Marine Species

Creator:: Curran, Lorne Sullivan
Abstract:: Population genetic techniques are now preeminent in differentiating wild populations. Natural resource managers rely on them in their efforts to restore viable populations of fish and wildlife. Overfishing adversely impacted Yelloweye Rockfish (Sebastes ruberrimus) on the U.S. West Coast in the late 20th century. Management actions included shutting down the...
Resource Type:: Masters Thesis

Beyond the Benthos: The effects of stream restoration on habitat complexity and aquatic and riparian macroinvertebrate assemblages

Creator:: Lotz, Kelsey L.
Abstract:: Aquatic and riparian systems in the western United States have been highly modified by anthropogenic impacts since Euro-American settlement. Ecological restoration is a practice that has been widely conducted around the world to mitigate the degradation of these systems. The majority of stream restoration efforts have focused on improving in-stream...
Resource Type:: Masters Thesis

Characterizing Microplastic Ingestion in Black Rockfish (Sebastes melanops) along the Oregon Coast

Creator:: Lasdin, Katherine S.
Abstract:: Microplastics (<5mm diameter) are present in a considerable number of marine and aquatic species. Understanding which species, the global spatial distribution, and what quantities of microplastics are present is extremely important for understanding the potential impacts they could have on recreationally important organisms and for the assessment of risk. We...
Resource Type:: Masters Thesis

Influence of Oceanographic Conditions on Copepod (Calanus pacificus) Genetic Expression

Creator:: Bynes, Kenya S.
Abstract:: RNAseq data among copepods (Calanus pacificus) were sampled and analyzed in relation to oceanographic and climatic conditions to determine if new information derived from such an approach might assist applications that use copepods as ecosystem indicators to predict fishery yields. These samples were taken as part of long-term studies conducted...
Resource Type:: Masters Thesis

Characterizing Fine-Scale Neutral and Adaptive Genetic Diversity of Oncorhynchus mykiss in the Klamath Basin Before Dam Removal

Creator:: Piotrowski, Stanley J.
Abstract:: An inextricable link exists between dams and human development in the Pacific Northwest, but they can fragment rivers and reduce genetic connectivity for freshwater and anadromous fishes. Since the early-twentieth century, a series of hydropower and irrigation dams on the mainstem Klamath River, California, has fragmented migratory corridors and eliminated...
Resource Type:: Masters Thesis

Spatial Variation in Ecosystem Carbon Stocks and Emissions Resulting from Land-use Conversion: Two Studies in Mangrove Forests of the Dominican Republic

Creator:: Giovannoni, Leila R.
Abstract:: Mangrove forests store more organic carbon across ecosystem carbon pools than most other coastal and forested ecosystems, and are subject to high global rates of deforestation. For these reasons, they are recognized as prime candidates for inclusion in climate change mitigation strategies. However, the ecological drivers of regional and micro-scale...
Resource Type:: Masters Thesis

Making the Connection: Linking Stress Physiology of Juvenile Northern Spotted Owls to Environmental Variation and Long-term Survival

Creator:: Mikkelsen, Ashlee J.
Abstract:: The northern spotted owl (Strix occidentalis caurina; spotted owl) is of conservation concern and endemic to mature forests of the Pacific Northwest. Adult survival has a strong effect on population growth rate, but juvenile survival and recruitment are also important components of population change. Despite the importance of this life...
Resource Type:: Masters Thesis

Assessing Renesting Rate and Survey Methods of Red Phalarope (Phalaropus fulicarius), a Polyandrous Arctic-breeding Shorebird

Creator:: Cosgrove, Jillian M.
Abstract:: The life history traits of polygamous, non-territorial shorebirds like the Red Phalarope (Phalaropus fulicarius) can make it challenging to assess their population status. There are two general approaches to statistical inference used to understand shorebird (Order: Charadriiformes) population change: design-based inference, which implements an a-priori sampling scheme with known selection...
Resource Type:: Masters Thesis

Tonight’s Specials Include Mysids, Amphipods, and More: An Examination of the Zooplankton Prey of Oregon Gray Whales and its Impact on Foraging Choices and Prey Selection

Creator:: Hildebrand, Lisa
Abstract:: Understanding prey quality and prey selection by predators is critical for management efforts aimed at identification and protection of essential habitats and prey. Marine predators must make daily foraging choices in a heterogenous and dynamic environment in order to meet the high energetic demands of migration, reproduction and foraging. With...
Resource Type:: Masters Thesis

The Role of Grazing and Weather in Nest Predator-Prey Dynamics and Reproductive Success of Sagebrush-obligate Songbirds

Creator:: Schroeder, Vanessa M.
Abstract:: Livestock grazing occurs worldwide, spanning over 25% of land globally. Effective conservation of biodiversity relies upon understanding the interactions of agricultural management practices and increasingly variable weather associated with climate change. I evaluated grazing, weather and predator-prey interactions within a grazing experiment in the sagebrush ecosystem of southeastern Oregon. I...
Resource Type:: Masters Thesis

Temporal Variation in the Prey Resource Portfolio of Juvenile Salmonids During Freshwater Rearing

Creator:: Brady, Megan E.
Abstract:: Freshwater rearing is a critical period in the life cycle of anadromous salmonids, known to produce carry-over effects mediating long-term growth and survival. Freshwater growth is primarily determined by food availability and temperature. While many species of salmon rear in freshwater for a full year or longer, most trophic ecology...
Resource Type:: Masters Thesis

Using Spatial Capture-Recapture to Estimate Density of Roosevelt Elk in Western Oregon

Creator:: Nelson, Jennifer E.
Abstract:: Spatial capture-recapture (SCR) is employed for estimating abundance and density of species, particularly those that are cryptic or solitary, and evaluating how population density varies with habitat. However, it is uncertain whether estimates are biased when applied to species that aggregate, such as elk (Cervus canadensis). Wildlife managers in the...
Resource Type:: Masters Thesis

The physiological response of larval Pacific lamprey to chronic heat stress

Creator:: Carilli, Patrick B.
Abstract:: Pacific lamprey is an important cultural and ecological species to freshwater ecosystems of the Pacific Northwest. Lamprey often rear in low gradient portions of watersheds that have high exposure to climate warming, yet very little is known about their thermal physiology in comparison with other anadromous fishes such as Pacific...
Resource Type:: Masters Thesis

Evaluating the Effects of a Parasitic Copepod (Salmincola californiensis) on the Performance of Juvenile Chinook Salmon (Oncorhynchus tshawytscha)

Creator:: Neal, William T.
Abstract:: Pacific salmon (Oncorhynchus spp.) rearing in lakes and reservoirs have been known to become heavily infected with an ectoparasitic copepod (Salmincola californiensis). Little is known about the factors that affect the parasite infection prevalence and intensity. However, previous research suggests that the parasite may negatively affect the fitness and survival...
Resource Type:: Masters Thesis

Understanding Tolerance: Measuring and Modeling Human-Black Bear Interaction in Oregon

Creator:: Delie, Jackie S.
Abstract:: The social sciences are increasingly used in conservation to describe interactions and relationships between humans, wildlife, and ecosystems. Scientists and policy-makers have concluded that promoting human tolerance for wildlife is critical to the success of conservation efforts. Yet, the concept of tolerance is relatively new in the context of human-wildlife...
Resource Type:: Masters Thesis

Using DNA Metabarcoding to Study Interactions Between Native Bees and Plants: Technical Developments and Applications

Creator:: Arstingstall, Katherine A.
Abstract:: Pollination is an essential ecosystem service that sustains functioning ecosystems and aids in food production. In response to recent, widespread declines of managed and native bee populations, many land managers have shown interest in developing conservation and restoration plans for enhancing native bee habitat. However, there is a lack of...
Resource Type:: Masters Thesis

Impacts of Range Management Decisions on Native Pollinators: Innovative Grazing Practices and Riparian Restoration

Creator:: Mitchell, Scott R.
Abstract:: Animal pollination is critical to plant reproduction in agricultural and wildland ecosystems. Much of the production of seeds and fruits in natural areas, which underlie many food webs, depends on pollination services by insects. The taxon responsible for delivering the bulk of these services in most temperate systems is bees....
Resource Type:: Masters Thesis

Effects of Synchronous Low Flow and Temperature Maxima on Coastal Cutthroat Trout and Coastal Giant Salamander: An Experimental Approach

Creator:: Tinoco Pickens, Francisco Andrew
Abstract:: As regional climates warm in the Pacific Northwest, USA, flow minima and temperature maxima may become more synchronous in headwater streams over time. The dual stresses from lower flows and warmer temperatures will be energetically costly for cold-water species such as Coastal Cutthroat Trout and Coastal Giant Salamander. Individual fates...
Resource Type:: Masters Thesis

Restoration of Pigeon Guillemot Nesting Habitat Through Removal of Introduced Predators

Creator:: Stark, Samuel B.
Abstract:: The 1989 Exxon Valdez oil spill (EVOS) in Prince William Sound, Alaska provided impetus for a great deal of research into the ecosystems of the Northern Gulf of Alaska. Buried within the multitude of resulting impacts, which included hundreds of thousands of oiled seabirds and dramatic ecosystem shifts in the...
Resource Type:: Masters Thesis

Evaluating Fish Rescue as a Drought Adaptation Strategy for Imperiled Coho Salmon: A Life-Cycle Modeling Approach

Creator:: Beebe, Brittany A.
Abstract:: Projected intensification of drought as a result of climate change may reduce the capacity of streams to rear fish, exacerbating the challenge of recovering ESA-listed salmon populations. Without management intervention, some stocks will likely go extinct as stream drying and fragmentation reduce juvenile survival to unsustainable levels. To offset drought-related...
Resource Type:: Masters Thesis

Feeding Ecology and Food Web Linkages of Yearling Chinook Salmon (Oncorhynchus tshawytscha) Migrating Through the Lower Columbia River and Estuary

Creator:: Munguia, Angelica
Abstract:: The Columbia River Basin historically supported abundant populations of Pacific salmon (Oncorhynchus spp.) but, largely due to anthropogenic influence, many populations are now listed as threatened or endangered under the U.S. Endangered Species Act. Habitat restoration efforts have been a critical component of salmon recovery plans. However, although the importance...
Resource Type:: Masters Thesis

Big Fishery, Big Data, and Little Crabs: Using a Genomic Approach to Examine Larval Recruitment Patterns of Dungeness Crab (Cancer magister) in the California Current Ecosystem

Creator:: Lee, Elizabeth M. J.
Abstract:: The California Current Ecosystem (CCE) is a dynamic marine ecosystem from which many socioeconomically important fisheries species are harvested. In this thesis, a genotyping-by-sequencing (GBS) approach was used to examine genomic variation in an early life stage of the Dungeness crab (Cancer magister), which constitutes the most valuable single-species commercial...
Resource Type:: Masters Thesis

Passive acoustic monitoring of owls: two studies in forested landscapes of the Pacific Northwest

Creator:: Duchac, Leila S.
Abstract:: Nearly all birds communicate through sound, and there has been much study of avian populations and communities using song and other vocalizations. Owls are no exception as they defend territories, advertise for mates, and defend against threats using various vocalizations. However, due to their generally nocturnal habits, some owl species...
Resource Type:: Masters Thesis

Comparing Migratory Patterns and Survival Between Wild and Wild Fish Surrogate Juvenile Spring Chinook Salmon (Oncorhynchus tshawytscha)

Creator:: Pollock, Amanda M. M.
Abstract:: Anadromous salmonid populations in the Pacific Northwest have declined over the past 150 years. In 1999, wild spring Chinook salmon (Oncorhynchus tshawytscha) were federally listed as threatened within the Willamette Basin, OR. Currently, practices to restore wild populations in the upper Willamette Basin involve trapping wild adults at the base...
Resource Type:: Masters Thesis

Otolith Morphometrics as a Tool for Conservation and Management of Chinook Salmon (Oncorhynchus tshawytscha)

Creator:: Koeberle, Alexander L.
Abstract:: Chinook salmon are widely distributed across the globe with native stocks in the North Pacific Ocean and self-sustained populations introduced to regions in the Northern and Southern Hemispheres. Pacific salmon are economically and ecologically important to the Pacific Northwest, USA, yet several wild populations are federally listed as endangered or...
Resource Type:: Masters Thesis

Using Satellite Imagery to Count Nesting Albatross from Space

Creator:: Dolliver, Jane E.
Abstract:: One fundamental concern in conservation biology is species abundance. For many taxa, however, these data are costly to obtain via direct observation and thus limited in geographic or temporal scope. Very high-resolution satellite imagery provides a means to address these limitations and provide remotely-sensed counts of large, colonial species. We...
Resource Type:: Masters Thesis

Spatial and Temporal Dynamics of Eulachon (Thaleichthys pacificus) in Northern Southeast Alaska

Creator:: Pochardt, Meredith R.
Abstract:: In Southeast Alaska, Eulachon (Thaleichthys pacificus) are a culturally and biologically important anadromous fish. Eulachon populations have significantly declined in the southern part of their range, and in 2010 eulachon in northern California, Oregon, and Washington were listed as a threatened species under the Endangered Species Act. In the same...
Resource Type:: Masters Thesis

Structural Variations of Headwater Stream Food Webs Along Geophysical Gradients at the HJ Andrews Experimental Forest

Creator:: Zatkos, Lauren E.
Abstract:: The structure of food webs and how they relate to community stability has been an important debate in ecology. Specifically, predictability of web shape and how it influenced by surrounding landscapes is one of the main goals of such discussions. Headwater streams provide a study template that is of interest...
Resource Type:: Masters Thesis

Salmon, Saws, and Sense of Place: Using a Discrete Choice Experiment to Examine Place Relationships and Preferences for Stream Restoration on the Quinault Indian Reservation

Creator:: Robinson, Kerrick W.
Abstract:: The social sciences have the capacity to contribute to natural resource management through investigations of human dynamics associated with the environment. Sense of place (SOP), the formed relationships between an individual and the environment, has been considered a fundamental aspect of human well-being and can contribute to more holistic understanding...
Resource Type:: Masters Thesis

Extrinsic and Intrinsic Factors Associated with Reproductive Success of Caspian Terns (Hydroprogne caspia) at East Sand Island, Columbia River Estuary

Creator:: Bailey, Olivia A.
Abstract:: Declines in wild salmonid (Oncorhynchus spp.) populations in the Columbia River basin have resulted in managers identifying that avian predation on juvenile salmonids is an important limiting factor for salmonid recovery. Caspian Terns (Hydroprogne caspia), particularly those nesting in the Columbia River estuary, were identified as key avian predators that...
Resource Type:: Masters Thesis

The Relationship between Hydroregime and Coho Salmon (Oncorhynchus kisutch) Spawning in Three Streams of the Smith River Watershed, Oregon

Creator:: Baxter, Mackenzie R.
Abstract:: Migration and spawning phenology of Pacific Salmon is linked to the hydroregime, and thought to be triggered by increases in river discharge and decreases in water temperature. However, little data exists that describes direct fine-scale linkages between the hydroregime and spawning in Coho Salmon. This study evaluated the spatial and...
Resource Type:: Masters Thesis

On the road to sustainability : Assessing Belize's fisheries management reform using a multiscalar governance approach

Creator:: Wade, Eric A.
Abstract:: The management of small-scale fisheries (SSF) around the world is facing increasing demands for reformation given ecological, social, and economic vulnerabilities. The governance of SSF is particularly important to foster the sustainability of these systems given that it combines regulatory instruments, interactive participation of diverse stakeholders, and the guiding values...
Resource Type:: Masters Thesis

Effects of Habitat Characteristics, Weather and Presence of Barred Owls (Strix varia) on Occupancy Dynamics and Breeding Propensity of Northern Spotted Owls (S. occidentalis caurina) in Mount Rainier National Park

Creator:: Mangan, Anna O.
Abstract:: For over 100 years, National Parks have existed to preserve America’s natural and cultural heritage for current and future generations. As environmental pressures on wildlife and habitats have increased in recent decades, National Park lands have become important protected areas for many threatened and endangered species. Conservation and management of...
Resource Type:: Masters Thesis

Movement, dive behavior, and habitat-use of common murres (Uria aalge) in the Northern California Current System under variable ocean conditions

Creator:: Loredo, Stephanie A.
Abstract:: Year-round habitat use of marine predators provides knowledge of important marine areas throughout different life stages. Large-scale, environmental variability, both in space and time, causes changes in the behavior and distribution of marine predators that are important to quantify for conservation. In the Northern California Current System (NCCS), common murres...
Resource Type:: Masters Thesis

An Investigation into the Distribution, Residency Patterns, Population Connectivity, and Abundance of Blue Whales (Balaenoptera musculus) in New Zealand

Creator:: Barlow, Dawn R.
Abstract:: Species conservation depends on robust population assessment. Data on population abundance, distribution, and connectivity are critical for effective management, especially as baseline information for newly documented populations. I describe a pygmy blue whale (Balaenoptera musculus brevicauda) population in New Zealand waters with year-round presence that overlaps with industrial activities. This...
Resource Type:: Masters Thesis

The Response of Caspian Terns to Managed Reductions in Nesting Habitat in the Columbia Plateau Region, Washington State, USA

Creator:: Schniedermeyer, Ethan
Abstract:: Declines in populations of anadromous salmonids (Oncorhynchus spp.) in the Columbia River drainage basin have resulted in extensive programs to annually release large numbers of hatchery-raised juvenile salmonids in an effort to support salmonid restoration. The Pacific Flyway population of Caspian terns (Hydroprogne caspia) has grown from around 3,500 nesting...
Resource Type:: Masters Thesis

Distribution, habitat associations, and conservation status of Pacific fisher (Pekania pennanti) in Oregon.

Creator:: Barry, Brent R.
Abstract:: Fishers (Pekania pennanti) are medium sized mustelids endemic to North America. Two fisher populations persist in Oregon: an indigenous population in southwestern Oregon, and a reintroduced population in the southern Cascade Mountains. Despite candidacy for listing under the Endangered Species Act, current information on fisher populations in Oregon is scarce....
Resource Type:: Masters Thesis

Spatiotemporal Associations of Abundance and Vital Rates of Co-occurring Small Mammals in a Late Successional Forest

Creator:: Weldy, Matthew J.
Abstract:: Informed conservation of small mammals, ecosystems, and predators requires a detailed understanding of how small mammals species and communities vary in both space and time, as well as the relative cyclicity and synchrony of this variation. This variation can be especially informative to land managers interested in manipulating the abundance...
Resource Type:: Masters Thesis

Evidence for Cross-Seasonal Effects: Insights from Long-term Data on Northern Pintail

Creator:: Zarzycki, Megan C.
Abstract:: Cross-seasonal effects, where conditions in one season can have consequences in a following season, can have population-level implications for migratory species. To assess the presence of cross-seasonal effects on a migratory dabbling duck population, we examined the relative importance of habitat conditions in multiple seasons on the subsequent productivity of...
Resource Type:: Masters Thesis

Factors Influencing Growth and Bioenergetics of Fish in Forested Headwater Streams Downstream of Forest Harvest

Creator:: Jensen, Leslie R.
Abstract:: In this study, we used a combination of conventional statistical analyses and mechanistic bioenergetics models to understand the potential effects of environmental variability on growth of stream-living fishes in four headwater streams subject to upstream forest harvest. We focused on two common fish consumers in headwater streams in the Pacific...
Resource Type:: Masters Thesis

The Effects of Tank Structure and Egg Size on the Production of Wild Steelhead (Oncorhynchus mykiss) Surrogate Fish

Creator:: Self, Katharine E.
Abstract:: One of the biggest hurdles for a juvenile salmonid (Oncorhynchus mykiss) is migrating downstream from freshwater spawning grounds to the ocean. Juveniles from wild broodstock were reared from the South Santiam River for more than 1 year at the Oregon Hatchery Research Center (OHRC) in Alsea, OR. The fish were...
Resource Type:: Masters Thesis

The Soundcheck of the Sea : Comparing Marine Soundscapes on a Continental Scale

Creator:: Haver, Samara M.
Abstract:: Monitoring marine ambient sound using standardized methods supports assessments of ocean sound levels across widespread ecosystems. This thesis quantifies differences among coastal and deep-water marine soundscapes in the Atlantic and Pacific oceans. The sources of sound in a soundscape are compartmentalized into three components and compared over time and among...
Resource Type:: Masters Thesis

Fine scale foraging behavior of gray whales in relation to prey fields and vessel disturbance along the Oregon Coast

Creator:: Sullivan, Florence A.
Abstract:: The desire to understand the spatial and temporal drivers of animal behavior and distribution relative to scale is central to movement ecology. Optimal foraging theory states that a predator should continue exploiting a patch until it is no longer profitable to do so. As human developments increasingly encroach on the...
Resource Type:: Masters Thesis

Temporal Variation in Humpback Whale (Megaptera novaeangliae) Demographics Along the Western Antarctic Peninsula

Creator:: Pallin, Logan J.
Abstract:: Humpback whale populations in Antarctica are recovering after intensecommercial whaling in the 20th century. Along the Western Antarctic Peninsula (WAP)this recovery is occurring in an environment that is experiencing the fastest warming ofany region on the planet. To begin to understand the dynamics of this recovery undersuch dramatic climate change,...
Resource Type:: Masters Thesis

Development of a Structured Adaptive Approach to Klamath Basin Sucker Recovery Planning

Creator:: Barajas, Miguel F.
Abstract:: Listed as endangered in 1988, the Lost River sucker (Deltistes luxatus) and Shortnose sucker (Chasmistes brevirostris) were once abundant and widely distributed in the Klamath Basin in Southern Oregon and Northern California. Populations of both species have been declining since the late 1960’s. Factors thought responsible for declines include naturally...
Resource Type:: Masters Thesis

Extensive Resource Subsidies by Salmon-Supported Bears to Granivores

Creator:: Shakeri, Yasaman N.
Abstract:: In salmon-rich, northern coastal environments brown bears can occur at high densities and exert wide-ranging effects on ecosystem processes. Bear consumption of seasonally available fruit may provide important seed dispersal services to plants, and by extension, influence the ecology of seed consumers such as small mammals. In this study, we...
Resource Type:: Masters Thesis

Double-crested Cormorants (Phalacrocorax auritus) and Brandt’s Cormorants (P. penicillatus) Breeding at East Sand Island in the Columbia River Estuary : Foraging Ecology, Colony Connectivity, and Overwinter Dispersal

Creator:: Peck-Richardson, Adam
Abstract:: Double-crested cormorants (Phalacrocorax auritus) and Brandt’s cormorants (P. penicillatus) nest sympatrically in a large mixed-species colony on East Sand Island (ESI) in the Columbia River estuary. Ecological theory predicts that such morphologically similar species will partition prey resources when faced with resource limitations. During the summer of 2014, I investigated...
Resource Type:: Masters Thesis

Long-term Fuel Succession in the Sagebrush-steppe

Creator:: Reis, Schyler Ainsworth
Abstract:: Historically fire has been the primary disturbance factor in the sagebrush-steppe. The settlement of the West by Euro-Americans, grazing by domestic livestock, and the concomitant spread of invasive species have altered the historical fire regime. Understanding the long-term vegetation structure and fuel succession of the various sagebrush-dominated communities of this...
Resource Type:: Masters Thesis

Effects of Elevated CO₂ on Speckled Sanddab (Citharichthys stigmaeus) Behavior

Creator:: Andrade, Jessica F.
Abstract:: The direct and indirect effects of ocean acidification (OA) are a growing concern, particularly in areas already experiencing elevated levels of oceanic CO₂. Studies with marine fishes suggest that elevated CO₂ levels may affect behavior by interfering with an important brain neurotransmitter. Studies examining the effects of OA fish behavior...
Resource Type:: Masters Thesis

Photo-identification of Melon-headed Whales (Peponocephala electra) in the Marquesas Islands : Creation of the First Photo-identification Catalog and Estimation of Group Size and Minimum Abundance in a Remote Archipelago

Creator:: McClung, John Ralph, II
Abstract:: For many species of oceanic dolphins, photo-identification and genetic data indicate that these island-associated populations are demographically isolated from pelagic populations and that island-associated populations exhibit very different patterns of movement and habitat use. Melon-headed whales (Peponocephala electra) are generally considered a pelagic dolphin, but have been documented around oceanic...
Resource Type:: Masters Thesis

Movement Patterns of Rockfishes at the Redfish Rocks Marine Reserve, Oregon

Creator:: Calvanese, Thomas P.
Abstract:: The effects of Marine protected areas (MPAs) on adult fish populations depend on the degree of protection provided, which is partly a function of MPA size and the spatial extent of fish movements. The Redfish Rocks Marine Reserve (RRMR) and MPA, located on the south coast of Oregon near Port...
Resource Type:: Masters Thesis

The Primacy of Mammals as Seed Dispersers and Predators in Salmon-Bearing Ecosystems

Creator:: Harrer, Laurie E. F.
Abstract:: Plants often encase seeds in a nutritional reward to incentivize seed dispersal by birds and mammals, but these seeds may also be removed and destroyed by seed predators. Although birds are typically thought to be the primary seed dispersers of berries in temperate systems, in southeast Alaska and other salmon-bearing...
Resource Type:: Masters Thesis

Foraging Niche Separation of Adélie (Pygoscelis adeliae) and Gentoo (P. papua) Penguins During the Breeding Season at Palmer Station, Antarctica

Creator:: Pickett, Erin
Abstract:: Climate-induced range overlap can result in novel interactions between similar species and potentially lead to competitive exclusion. The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth and is experiencing a poleward climate migration. This transition from a polar to sub-polar environment has resulted in a...
Resource Type:: Masters Thesis

Spatio-temporal Patterns and Ecological Drivers of Harbor Porpoise (Phocoena phocoena) off the Central Oregon Coast, USA

Creator:: Holdman, Amanda
Abstract:: The marine environment is under increasing pressure from human activities worldwide, particularly in coastal waters, creating a need to better understand fine-scale distributions of highly mobile species that occur in the area, as they are frequently most threatened. Harbor porpoise (Phocoena phocoena) occur frequently in Oregon’s nearshore habitat, but due...
Resource Type:: Masters Thesis

Genetic Connectivity of Dungeness Crab (Cancer magister) in the California Current System and Puget Sound

Creator:: Jackson, Tyler M.
Abstract:: Understanding connectivity among exploited populations is critical to their sustainable management and long-term viability. In the marine environment, estimates of connectivity often rely on the use of genetic markers, as dispersal primarily occurs during a planktonic larval phase which is difficult to track using direct methods. In this thesis, we...
Resource Type:: Masters Thesis

The Impact of Parasitic Copepod Salmincola Californiensis on Swimming Ability & Oxidative Burst Activity in Response to Stress in Juvenile Chinook Salmon

Creator:: Herron-Seeley, Crystal L.
Abstract:: Juvenile Chinook Salmon (Oncorhynchus tshawytscha) have a finite amount of energy that they can use to move from their riverine habitat to their oceanic habitat. Fish in the Willamette River Basin are prevented from moving to the ocean easily by dams which create reservoirs, where they reside for up to...
Resource Type:: Masters Thesis

The Effect of Group Size on Individual Roles and the Potential for Cooperation in Group Bubble-net Feeding Humpback Whales (Megaptera novaeangliae)

Creator:: Mastick, Natalie
Abstract:: Group foraging is observed in many species as a means to increase the ability of members of the group to find and exploit patchy prey. Group foraging can be exhibited in a number of different contexts based on the relationships between the participants, including by-product mutualism. One variant of by-product...
Resource Type:: Masters Thesis

Spatial Association of Humpback Whales (Megaptera novaeangliae) and their Prey in the Southern Gulf of Maine, USA

Creator:: Kirchner, Theresa
Abstract:: Efficient foraging strategies result in a predator spatially overlapping with its prey, foraging in the most profitable patches, and minimizing the time transiting between patches. Previous studies investigating baleen whale foraging strategies have generally focused on investigating spatial overlap with prey patches, patch profitability or movement within feeding grounds. The...
Resource Type:: Masters Thesis

A Comparative Study of Foraging Behavior and Disturbance Regimes in Urban Versus Agricultural Habitats used by Cackling Geese Wintering in the Willamette Valley, Oregon

Creator:: Harrington, Erin R.
Abstract:: The Cackling goose (Branta hutchinsii minima) population has increased from a low of 20,000 in 1984 to the current population of 220,000-300,000 (Stehn 2012, Sanders 2013). As the Cackling goose population began to recover in the late 1990s, the majority of the population relocated from wintering in California to the...
Resource Type:: Masters Thesis

The Impacts of Multiple Stressors on Aquatic Invertebrate Communities in the Umatilla River

Creator:: Clark, Hannah
Abstract:: Rivers impacted by human activities often have multiple stressors present. The effects of multiple stressors on biological communities can often be difficult to predict, due to the potential for complex interactions between stressors and communities. This thesis explores the impacts of two stressors often associated with agricultural land use, increased...
Resource Type:: Masters Thesis

Juvenile Rockfish (Sebastes spp.) Community Composition and Habitat use of Yaquina Bay, Oregon

Creator:: Lindsley, Amy J.
Abstract:: Estuaries, which provide viable habitat for a plethora of fish and invertebrate species, are being increasingly impacted by anthropogenic and natural forces. Estuaries are important nursery habitat for young-of-the-year (YOY) Pacific rockfish (Sebastes spp.). Yaquina Bay, a marine-dominated estuary on the central Oregon Coast, served as a study site for...
Resource Type:: Masters Thesis

Estimation of Population Age Structure, Detection Probability, and Density of Red Tree Voles in Oregon

Creator:: Marks-Fife, Chad A.
Abstract:: Red tree voles (Arborimus longicaudus) are a unique species of Arvicoline rodent found in western Oregon and northwest California. Their preferred habitat is mature and old-growth coniferous forest dominated by Douglas-fir (Pseudotsuga menziesii). Tree voles are an important prey item for northern spotted owls and many other predators, but are...
Resource Type:: Masters Thesis

Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire

Creator:: Foster, Lee
Abstract:: Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern...
Resource Type:: Masters Thesis

Thirty-four Kilometers and Fifteen Years : Rapid Adaptation at a Novel Chromosomal Inversion in Recently Introduced Deschutes River Three-spined Stickleback

Creator:: Hemstrom, William
Abstract:: Rapid adaptation and evolution based on standing genetic variation and novel mutations is likely to be one of the primary ways that species survive the widespread anthropogenic environmental changes expected of the next century. Three-spined stickleback (Gasterosteus aculeatus) are known to be capable of extremely quick, dramatic adaptation in response...
Resource Type:: Masters Thesis

Twenty-year changes in riparian bird communities of east-central Oregon

Creator:: Ellis, Michael S.
Abstract:: Over the last 50 years, riparian zones in the semi-arid West have gained recognition as disproportionately important habitats for both breeding bird communities and agricultural operations. Despite growing interest in exploring avian-habitat relationships in these systems to better inform land management, few studies have attempted to describe temporal changes in...
Resource Type:: Masters Thesis

Juvenile Coho Salmon (Oncorhynchus kisutch) Diet in Brackish and Freshwater Habitats in the Stream-estuary Ecotones of Coos Bay, Oregon

Creator:: Mackereth, Kailan F.
Abstract:: Loss of lowland estuarine and freshwater off-channel habitats along the Pacific Northwest coast has contributed to the decline of salmonid populations. These habitats serve as nursery grounds for juvenile salmonids providing them with food, winter shelter, and a transition zone between freshwater and saltwater. Lowland areas have undergone anthropogenic alterations...
Resource Type:: Masters Thesis

Resource Selection and Space Use of Western Long-eared Myotis (Myotis evotis) in a Western Juniper (Juniperus occidentalis) Woodland of Central Oregon

Creator:: Anthony, Christopher R.
Abstract:: Identifying habitat and spatial requirements of wildlife species across multiple spatial scales is a challenging, yet crucial component of wildlife management. Habitat use of bats is particularly difficult to study, and managing habitat to conserve bats is especially challenging because bats are highly vagile organisms that exploit several different types...
Resource Type:: Masters Thesis

Dispersal Behavior in African Buffalo (Syncerus caffer) : Tradeoffs Between Nutritional Resources and Disease Exposure

Creator:: Spaan, Robert Steven
Abstract:: Dispersal facilitates population health and maintains resilience in species via gene flow. Adult dispersal occurs in some species, is often facultative, and is poorly understood, but has important management implications, particularly with respect to disease spread. Although the role of adult dispersal in spreading disease has been documented, the potential...
Resource Type:: Masters Thesis

Survival Rates and Cause-Specific Mortality of Mule Deer in South-Central Oregon

Creator:: Mulligan, Elizabeth M.
Abstract:: It is critical for wildlife managers to understand the population dynamics of a harvested species, particularly for ungulates, which are a valuable wildlife resource. Due to concerns that mule deer (Odocoileus hemionus) populations in Oregon were declining, more comprehensive data on population vital rates and the factors potentially affecting them...
Resource Type:: Masters Thesis

Tempo and Mode of Diversification in the Neotropical Fish Superfamily Anostomoidea (Ostariophysi: Characiformes)

Creator:: Frable, Benjamin W.
Abstract:: Neotropical characiform fishes form one of the most diverse freshwater ichthyofauna in the world. Knowledge of evolutionary processes that generated and maintain the immense characiform lineage and morphological diversity is still poorly understood. When did characiform lineages diversify? How have major geological and environmental changes affected diversification? Why are some...
Resource Type:: Masters Thesis

Vegetation and Small Mammal Responses to Western Juniper (Juniperus occidentalis) Control in Eastern Oregon

Creator:: Morozumi, Corinne N.
Abstract:: Shrub-steppe ecosystems of western North America provide habitat for many wildlife species, are important components of public and private rangelands, and offer recreational opportunities for millions of people. They are some of the most vulnerable ecosystems in the United States and have been altered by human activities such as livestock...
Resource Type:: Masters Thesis

Population Ecology of the Mariana Swiftlet (Aerodramus bartschi) on O'ahu, Hawaiian Islands

Creator:: Johnson, Nathan Christopher
Abstract:: The Mariana Swiftlet (Aerodramus bartschi) (Aves: Apodidae) is endemic to the Mariana Islands, where it currently occurs on Saipan, Aguiguan, and Guam. An introduced population of Mariana Swiftlets is also present on O'ahu in the Hawaiian Islands. Sparing interference with the endangered population in the Marianas, the introduced, surrogate population...
Resource Type:: Masters Thesis

Historic Survival Rates and Cause-Specific Mortality for Columbian Black-Tailed Deer in Southwest Oregon

Creator:: Groot, Kevyn A.
Abstract:: In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon...
Resource Type:: Masters Thesis

Effects of Current Hatchery Practices on Salmon Odor Recognition and Responses

Creator:: Lemanski, Joseph R.
Abstract:: Salmon hatcheries have been utilized throughout the Pacific Northwest for many decades to mitigate losses, supplement natural spawning populations, and to provide tribal, sport and commercial fishing opportunities. Currently, there is substantial debate on their efficacy and the potential threats hatchery-reared salmonids pose to natural populations. These concerns have lead...
Resource Type:: Masters Thesis

Where the Stream Meets the Road : Prioritizing Culvert Replacement for Fish Passage

Creator:: Reagan, Rachel E.
Abstract:: Streams across the world are highly fragmented due to the presence of in-stream barriers (e.g., dams and stream-road crossings), many of which restrict or block fish passage. Retrofitting or replacing these structures is a high priority for restoring habitat connectivity for native fishes and other aquatic organisms in the Pacific...
Resource Type:: Masters Thesis

An Evaluation of the Effects of Hatchery and Management Practices on Geomagnetic Orientation Behavior in Juvenile Pacific Steelhead Trout (Oncorhynchus mykiss)

Creator:: Scanlan, Michelle M.
Abstract:: Numerous populations of salmon and trout undergo extensive migrations, migrating from freshwater to the sea and throughout ocean basins. Years later they return to their natal streams with remarkable accuracy and precision. The outward migration is accomplished without the benefit of following experienced migrants or prior individual experience. Evidence suggests...
Resource Type:: Masters Thesis

Stock Synthesis Assessments of Spatially Structured Fish Populations with an Environmental Driver on Recruitment Distribution : A Simulation Study and Discussion

Creator:: Denson, LaTreese S.
Abstract:: Stock assessments use statistical models and empirical data to re-create the population dynamics of a stock in order to provide estimates of biomass and fishing mortality rates to inform fisheries management. Fish stocks are not uniformly distributed across spatial regions, but stock assessments typically ignore stock spatial structure, for the...
Resource Type:: Masters Thesis

Pre- and Post-settlement Processes of Northern Rock Sole (Lepidopsetta polyxystra) in Relation to Interannual Variability in Temperature and Productivity in the Gulf of Alaska

Creator:: Fedewa, Erin J.
Abstract:: Understanding the effects of climate variability on growth dynamics and timing of early life history events in marine fishes can provide insights into survival, recruitment and productivity. Field collections (2005, 2007, 2009-2011) were combined with otolith microstructural analysis to examine interannual variation in larval and juvenile growth rates, size at...
Resource Type:: Masters Thesis

Development and Evaluation of an Animal-borne Active Acoustic Tag to Conduct Minimally Invasive Behavioral Response Studies on Marine Mammals

Creator:: Fregosi, Selene
Abstract:: Development of new research tools is needed to better understand the potential effects of a noisier ocean on individual and populations of marine mammals. Current behavioral response studies utilize ship-mounted sound sources to induce short-term noise-related behavioral responses in tagged animals. Combining the tag with the sound source into an...
Resource Type:: Masters Thesis

Provisioning, growth and survival of Adélie penguin chicks at Cape Crozier, Ross Island, Antarctica

Creator:: Jennings, Scott
Abstract:: Understanding the factors that contribute to or limit reproductive success is a fundamental objective of the field of ecology, providing insight into the ways ecosystems function and facilitating better management of natural resources. Behaviors that benefit offspring often increase costs to parents, and thus parents must adjust their level of...
Resource Type:: Masters Thesis

Evaluating tools used to estimate and manage browse available to wintering moose on the Copper River Delta, Alaska

Creator:: Smythe, Sharon E.
Abstract:: Ungulates comprise some of the most well researched and intensely managed wildlife populations on earth. As such, they are recognized as ideal study subjects for developing and modifying management tools or theories (Danell et al. 1994, Shipley 2010). An introduced moose (Alces alces gigas) population on the Copper River Delta...
Resource Type:: Masters Thesis

Mercury bioaccumulation in remote subalpine lakes : assessing the influence of invasive trout on salamanders

Creator:: Pfleeger, Adam
Abstract:: Mercury (Hg) contamination is a global conservation threat to freshwater ecosystems, detected in even the protected lakes of Olympic National Park (Washington, USA). Although considered some of the most remote and pristine US ecosystems, these lakes are currently subject to multiple environmental stressors, including climate change and fish introductions; adding...
Resource Type:: Masters Thesis

Pacific lamprey Entosphenus tridentatus : integrating traditional ecological knowledge and contemporary values into conservation planning, and stream substrate associations with larval abundance in the Willamette River Basin, Oregon, U.S.A.

Creator:: Sheoships, Gabe
Abstract:: Pacific lamprey Entosphenus tridentatus is a valuable icon and traditional food source for Indigenous people of western North America. Native Americans have utilized traditional ecological knowledge (TEK) since time immemorial to guide their ways of life, transmitting cultural values and natural history to further generational knowledge. Pacific lamprey are in...
Resource Type:: Masters Thesis

Early self-sorting behavior in Chinook salmon is correlated with variation in growth, behavior and morphology later in life.

Creator:: Unrein, Julia R.
Abstract:: Juvenile Chinook salmon (Oncorhynchus tshawytscha) exhibit an array of life history tactics in Oregon's Willamette River Basin, yet we do not know to what extent it is driven by phenotypic plasticity or whether it is predetermined and how conditions in the early rearing environment may affect phenotype expression. We have...
Resource Type:: Masters Thesis

Sequential isotopic analysis to characterize ontogenetic shifts and growth dynamics of loggerhead sea turtles (Caretta caretta)

Creator:: Ramirez, Matthew D.
Abstract:: Ontogenetic niche theory predicts that as organisms grow they make size-specific changes in habitat use and diet to optimize growth and survival. A variety of factors contribute to growth and survival in different habitats, ultimately leading to variation in life history that can affect population dynamics. An understanding of the...
Resource Type:: Masters Thesis

Responses of juvenile coho salmon and larval lamprey to instream habitat restoration in a Pacific Northwest stream

Creator:: Gonzalez, Rosalinda
Abstract:: Large wood has been utilized in many restoration projects to improve in-stream habitat in the Pacific Northwest for salmon. However, the benefits of this practice remain the subject of ongoing debate and evaluation of these projects has scarcely been done for non-salmonid species such as lamprey. In this study we...
Resource Type:: Masters Thesis

Life-history strategies of rainbow trout (Oncorhynchus mykiss) across a volcanic disturbance gradient at Mount St. Helens, Washington

Creator:: Blackman, Tara Elizabeth
Abstract:: In this study, I examine the influence of habitat gradients created by the 1980 eruption of Mount St. Helens, Washington USA on a recently established Rainbow Trout (Oncorhynchus mykiss) population in the Spirit Lake basin. My goal was to evaluate the responses of fish in seven streams across a volcanic...
Resource Type:: Masters Thesis

Assessment of mule deer fawn survival and birth site habitat attributes in south-central Oregon

Creator:: Speten, David
Abstract:: Mule deer (Odocoileus hemionus) populations in south-central Oregon are near their lowest levels since census efforts began in 1961. I investigated fawn survival, cause-specific mortality, and factors contributing to mortality from 2010 – 2012 to identify potential causes for the decline. I also explored pre-parturition and parturition site characteristics. I...
Resource Type:: Masters Thesis

Bioenergetic evaluation of diel vertical migration by bull trout

Creator:: Eckmann, Madeleine
Abstract:: I evaluated hypotheses related to growth as a driver of depth use and diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir. I applied a bioenergetic model to evaluate growth of bull trout in relation to potential patterns of diel depth use by bull trout in...
Resource Type:: Masters Thesis

The influence of local fidelity and recruitment on population dynamics and specialized foraging of humpback whales in Glacier Bay and Icy Strait, Alaska

Creator:: Pierszalowski, Sophie Penny
Abstract:: Humpback whales (Megaptera novaeangliae, Borowski 1781) in the North Pacific migrate from mid- to high- latitude summer feeding grounds along the Pacific Rim, including areas off the coasts of the U.S., Canada, Russia and eastern Asia, to tropical breeding grounds each winter along Pacific coasts of Mexico and Central America...
Resource Type:: Masters Thesis

Effects of genetic drift, natural selection, and population connectivity on adaptive-linked genetic diversity of desert bighorn sheep

Creator:: Nickerson, Brandon Scott
Abstract:: The amount and distribution of neutral and adaptive genetic diversity are often assumed to follow similar patterns. However, natural selection on adaptive loci may cause divergence from patterns observed for loci which are only influenced by selectively neutral processes such as genetic drift. The interaction between selection and neutral processes...
Resource Type:: Masters Thesis

60 years of avian community change in the Willamette Valley, Oregon

Creator:: Curtis, Jenna
Abstract:: Birds perform valuable ecological functions and are useful environmental indicators. Avian distributions and diversity are predicted to change over the next 50 years. Little information exists on the role of local and regional conditions in fluctuations of avian communities over time. Historic datasets present a legacy of information that helps...
Resource Type:: Masters Thesis

Evaluating the data-poor fishery stock assessment method, DB-SRA

Creator:: Owashi, Brandon R.
Abstract:: Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per...
Resource Type:: Masters Thesis

Cruise ship disturbance to Kittlitz's murrelets (Brachyramphus brevirostris) in Glacier Bay National Park and Preserve, Alaska

Creator:: Marcella, Timothy K.
Abstract:: The Kittlitz's murrelet (Brachyramphus brevirostris), a small pursuit-diving seabird in the family Alcidae, occurs across much of coastal Alaska and parts of the Russian Far East. Glacier Bay National Park, located in Southeast Alaska, is believed to support approximately 37% of the worldwide breeding population of Kittlitz's murrelets during the...
Resource Type:: Masters Thesis

Patterns of distribution, abundance, and change over time in the marine bird community of Prince William Sound, Alaska, 1989-2012

Creator:: Cushing, Daniel A.
Abstract:: Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment. Studies of top marine consumers can provide insights into processes of ecosystem change. Using data collected...
Resource Type:: Masters Thesis

Top-down Influences of bald eagles on common murre populations in Oregon

Creator:: Horton, Cheryl A.
Abstract:: Populations of organisms are influenced by both top-down (predator driven) and bottom-up (environment or resource driven) effects. Seabird research has largely focused on bottom-up factors influencing reproduction, with little emphasis on top-down. Our goal was to better understand top-down impacts on colonial nesting seabirds over a range of spatio-temporal scales....
Resource Type:: Masters Thesis

Cool, pathogen free refuge lowers pathogen associated prespawn mortality of Willamette River Chinook salmon (Oncorhynchus tshawytscha)

Creator:: Benda, Susan
Abstract:: Spring Chinook salmon, Oncorhynchus tshawytscha, are transported above dams in the Willamette River to provide access to blocked spawning habitat. However, 30-95% of these transplants may die before spawning in some years. To varying degrees, salmon in other tributaries--both blocked and unblocked--have similar prespawn mortality (PSM). Our study determined if...
Resource Type:: Masters Thesis

Butterfly and flower community composition among prairie-oak ecosystem habitats in the Willamette Valley, Oregon

Creator:: Powers, Breanna F.
Abstract:: Prairie-oak ecosystems in the Willamette Valley, Oregon have experienced habitat loss and degradation; most of these ecosystems are fragmented into smaller patches. Prairie-oak butterfly species, in the Willamette Valley, have decreased dramatically due to loss or degradation of habitat. More research is needed on sustaining the populations of butterflies in...
Resource Type:: Masters Thesis

Habitat relationships of native and non-native fishes of the Willamette River, Oregon

Creator:: Williams, Joshua E.
Abstract:: The Willamette River flows north between the Cascade Mountains and Coast Range of western Oregon within a 29,728-km² basin. The fish community in the geologically young basin consists of 36 native species, but introductions of non-native fishes have added 33 additional species for a total of 69 fish species. During...
Resource Type:: Masters Thesis

Effects of oil and natural gas development on territory occupancy of ferruginous hawks and golden eagles in Wyoming, USA

Creator:: Wallace, Zachary P.
Abstract:: Energy development is expanding rapidly across the western US. Negative effects have been documented for some wildlife, but consequences of development are unclear for other taxa, including raptors. We had the opportunity to examine effects of oil and natural gas development on two raptor species of conservation concern, ferruginous hawks...
Resource Type:: Masters Thesis

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