Index Catalog // ScholarsArchive@OSU

Heterospecific information transfer within a guild of avian scavengers in Central Oregon

Creator:: Weidner, Emily C., Nelson, Jon D., and Orr, Matthew
Abstract:: Heterospecific competition for carrion may influence community structure as dominant species are predicted to exploit subordinate, social species to find food. We used camera traps and ungulate carcasses to assess scavenger interactions in central Oregon. Preliminary analyses indicate that raptor arrival at carcasses correlated with arrival of ravens (Corvus corax)...
Resource Type:: Poster

Short-tailed weasel space use in managed forests of western Oregon

Creator:: Linnell, Mark A.
Abstract:: Although short-tailed weasels (Mustela erminea) are important predators of small mammals, little is known about their space use, habitat selection, or vulnerability to predation in North America. To evaluate the effects of forest management and social structure on home range size and habitat selection of short-tailed weasels, I conducted a...
Resource Type:: Masters Thesis

Foraging behavior of the Pacific harbor seal (Phoca vitulina richardii) in the Pacific Northwest and potential impacts of coastal hypoxia on foraging efficiency

Creator:: Steingass, Sheanna M.
Abstract:: In the last decade, the California Current Large Marine Ecosystem has experienced a trend of increased severity of upwelling-driven coastal hypoxia. This thesis strove to examine the potential upper trophic level impacts of moderate and severe hypoxia in the CCLME. Initially I conducted a literature review of Pacific harbor seal...
Resource Type:: Masters Thesis

Contribution of subyearling estuarine migrant coho salmon (Oncorhynchus kisutch) to spawning populations on the southern Oregon coast

Creator:: Nordholm, Katherine E.
Abstract:: The typical coho salmon life history has been characterized by juvenile fish that spend their entire first year in freshwater habitats before migrating into estuaries as smolts. However, reports of early migrating coho fry (age 0), including migration downstream to estuarine habitats, date back to the 1960s. Until a few...
Resource Type:: Masters Thesis

Implications of cougar prey selection and demography on population dynamics of elk in northeast Oregon

Creator:: Clark, Darren A.
Abstract:: Mule deer (Odocoileus hemionus hemionus) and Rocky Mountain elk (Cervus canadensis nelsoni; hereafter elk) populations in northeast Oregon have declined in the past 10 to 20 years. Concurrent with these declines, cougar (Puma concolor) populations have apparently increased, leading to speculation that predation by cougars may be responsible for declining...
Resource Type:: Dissertation

Movement and space use by the green hermit (Phaethornis guy) in a fragmented landscape in Costa Rica

Creator:: Volpe, Noelia L.
Abstract:: Human activities have altered Earth’s ecosystems. Most biomes have experienced a 20-50% conversion to human use. Loss of habitat has obvious effects on the persistence of species. Fragmentation, however, may also negatively affect biodiversity for those species that exhibit behavioral responses to changes in habitat configuration. Such behavioral changes include...
Resource Type:: Masters Thesis

Patch dynamics of desert fishes in the arid wetlands of western Utah

Creator:: Sáenz, Jessica
Abstract:: The conservation of declining desert fish species requires the identification of relations between fish population dynamics and their environments. Dynamic occupancy modeling, an approach that requires less information than traditional mark-recapture studies, may help identify important factors affecting population processes and aid desert fish conservation and restoration efforts. I used...
Resource Type:: Masters Thesis

All in a DNA's work : conservation genetics and monitoring of the New Zealand endemic Maui's and Hector's dolphins

Creator:: Hamner, Rebecca Marie
Abstract:: The critically endangered Maui's dolphin (Cephalorhynchus hectori maui) and the endangered Hector's dolphin (C. h. hectori) are endemic to the coastal waters of New Zealand, where their primary threat is fisheries-related mortality. The Maui's dolphin is among the most critically endangered cetaceans in the world, with its remnant population primarily...
Resource Type:: Dissertation

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

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

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

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

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

The effects of environmental stressors on cardiac gene expression and contractility in rainbow trout (Oncorhynchus mykiss)

Creator:: Momoda, Tracey S.
Abstract:: Rainbow trout (Oncorhynchus mykiss) experience a variety of stressors in their natural environment as well as in aquaculture that can have negative effects on their physiology. The effects of physiological stress and endocrine disruption have been well described in fish. However, there is a scarcity of information on the effects...
Resource Type:: Dissertation

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

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

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

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

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

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

The influence of social structure and molecular evolution on genetic diversity in the sperm whale (Physeter macrocephalus)

Creator:: Alexander, Alana
Abstract:: The sperm whale (Physeter macrocephalus) shows some of the most derived characteristics of any mammal: a large body size, large brain, complex social organization and a capacity for deep foraging dives that few other marine mammals can match. Despite a history of exploitation that removed hundreds of thousands of individuals,...
Resource Type:: Dissertation

Optimal Foraging: Some Theoretical Explorations

Creator:: Charnov, Eric L. and Orians, Gordon H.
Resource Type:: Book

Habitat use and movement behavior of Pacific marten (Martes caurina) in response to forest management practices in Lassen National Forest, California

Creator:: Moriarty, Katie M.
Abstract:: Some of the most pressing conservation concerns involve declining populations of species with low fecundity and highly specialized foraging and reproductive requirements. Yet, we often lack a functional understanding of how individuals of those species interact with their environment, specifically how their movement is affected by human-induced changes. In order...
Resource Type:: Dissertation

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

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

Genomics of migration : from marine distributions of salmonids to mechanisms of olfactory and magnetic cue perception for natal homing

Creator:: Bellinger, M. Renee
Abstract:: Substantial scientific investment has been directed towards understanding factors that influence distribution patterns and animals' remarkable ability for precise orientation and navigation, yet fundamental gaps in our knowledge remain. In my dissertation, I applied emerging genetic technologies to conduct a top-down and bottom-up investigation of animal movement and cue perception....
Resource Type:: Dissertation

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

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

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

California condors in the Pacific Northwest : integrating history, molecular ecology, and spatial modeling for reintroduction planning

Creator:: D'Elia, Jesse
Abstract:: Reintroduction programs are increasingly being used to save animals from extinction and aid in their recovery. The California Condor (Gymnogyps californianus), one of the most endangered birds in the world, is a remarkable example of how reintroduction programs can help rapidly increase a species' population numbers and range following a...
Resource Type:: Dissertation

Worldwide phylogeography and local population structure of the rough-toothed dolphin (Steno bredanensis)

Creator:: Albertson, G. Renee
Abstract:: Several dolphin species have global distributions. The extent of their radiation and limits to gene flow are presumably a product of oceanographic features both recent and historical, behavioral specializations and social organization. Rough-toothed dolphins (Steno bredanensis) are globally distributed in tropical and subtropical waters and are generally found in depths...
Resource Type:: Dissertation

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

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

Search Constraints

Search Results

Limit your search