Index Catalog // ScholarsArchive@OSU

Range-wide abundance and fluctuating asymmetry patterns of sagebrush-obligate passerine birds

Creator:: Krissman, Cortnie M.
Abstract:: North American sagebrush (Artemisia spp.) ecosystems are suffering from reductions in habitat extent and quality. Only about 50% of sagebrush remains from pre-settlement conditions, and much of the remaining habitat is fragmented or degraded by invasive species, fire suppression and overgrazing. Sagebrush-obligate species are experiencing population declines as a result...
Resource Type:: Masters Thesis
Full Text:: -nonsense truths, and was always a delight to be around. Committee member, Laura Nagy, was a voice of

Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations

Creator:: Johnson, Tracey N.
Abstract:: In grasslands, grazing by large ungulates can influence vegetation structure, composition, primary productivity, and ultimately, ecosystem functioning. While grazing represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation. Structural and compositional changes in the plant community caused by grazing could have bottom-up effects on species...
Resource Type:: Dissertation
Full Text:: Pyke, and especially, Dr. Laura Nagy, who made significant contributions to the project overall and

Disturbance and roosting ecology of California brown pelicans (Pelecanus occidentalis californicus) on East Sand Island in the Columbia River Estuary

Creator:: Wright, Sadie K.
Abstract:: The California brown pelican (Pelecanus occidentalis californicus) is listed as an endangered species under the U.S. Endangered Species Act. The Recovery Plan for this subspecies outlines the need to "Assure long-term protection of adequate food supplies and essential. . .roosting. . . habitat throughout the range." I investigated the effects...
Resource Type:: Masters Thesis
Full Text:: Columbia River Estuary. Abstract approved Robert G. Anthony The California brown pelican (Pelecanus

Relative abundance and habitat associations of small mammals in two forest types in southern Oregon

Creator:: Johnston, Aaron N.
Abstract:: I studied small-mammal communities and their response to grazing in mixed-conifer forests and oak woodlands in the Cascade-Siskiyou National Monument in southern Oregon. My objectives were to (1) compare small-mammal communities among forest types and grazing intensities, (2) identify riparian affiliated species, and (3) describe microhabitat associations. Over two years,...
Resource Type:: Masters Thesis
Full Text:: Robert G. Anthony I studied small-mammal communities and their response to grazing in mixed- conifer

Environmental contaminants and ecology of bald eagles in southcentral Oregon

Creator:: Frenzel, Richard Wilmarth
Abstract:: Food habits and levels of organochlorine compounds, lead, and mercury in resident and wintering bald eagles were studied in southcentral Oregon and California, 1979-83. Food habits were assessed by examination of castings from winter communal roosts, identification of 2938 prey items found at nest sites and foraging areas, and observations...
Resource Type:: Dissertation
Full Text:: : obert G. Anthony Food habits and levels of organochiorine compounds, lead, and mercury in resident and

Combining Disparate Data Sources with Ecosystem and Integrated Models: Case Studies for Improving Management of Protected Species

Creator:: Chasco, Brandon E.
Abstract:: Globally, the number of threatened species is increasing and conserving them is a high priority to the scientific community. Assessing the status of these protected species is challenging due to missing, contested, and or contradictory data streams. Integrated models (IMs) provide a statistical framework for combining disparate data sources to...
Resource Type:: Dissertation
Full Text:: (E), west coast of Vancouver Island/British Columbia (F), southeast Alaska (G), and the Gulf of

Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary

Creator:: Lyons, Donald E.
Abstract:: This dissertation focuses on the predator-prey relationship between two species of avian predators, Caspian terns (Hydroprogne caspia) and double-crested cormorants (Phalacrocorax auritus), and one of their important prey types, juvenile salmonids (Oncorhynchus spp.), in the Columbia River estuary of Oregon and Washington states during the period 1998 – 2007. I...
Resource Type:: Dissertation
Full Text:: aspects of each chapter included herein. Dr. G. Henk Visser provided assistance in chapter 3 with study

Hydrologic and vegetation responses associated with restoration of wetlands in the Willamette Valley, Oregon

Creator:: Coleman, Gregory A.
Abstract:: I examined hydrological and plant community changes associated with the implementation of a restoration management plan in two riparian meadows located within an agricultural landscape of the central Willamette Valley, Oregon. I established exclosure fencing (a form of passive restoration) in one agricultural field and established fencing and plugged a...
Resource Type:: Masters Thesis
Full Text:: by intense land management practices (e g., plowing, re-seeding, or removal of dominant plant

Nest Success and Cause-Specific Nest Failure of Grassland Passerines Breeding in Prairie Grazed by Livestock

Creator:: Johnson, Tracey N., Kennedy, Patricia L., and Etterson, Matthew A.
Abstract:: Livestock grazing is a widespread source of habitat modification, and may affect populations of ground-nesting grassland birds by influencing rates of nest failure. Nesting attempts can fail for various reasons, and determining risk of failure from specific causes associated with livestock grazing would enhance development of range management practices in...
Resource Type:: Article
Full Text:: who helped with data collection. L. Nagy, K. Dugger, R. Miller, D. Pyke, and G. Niemi made com- ments

Population Genetics of American Pika (Ochotona princeps) : Investigating Gene Flow and Genetic Diversity Across Multiple, Complex Landscapes

Creator:: Castillo, Jessica A.
Abstract:: American pikas (Ochotona princeps) are considered an indicator species of climate change. Adaptations for cold climates and active winters make pikas particularly sensitive to increasing temperatures. This, combined with evidence that multiple historically occupied populations have been extirpated within the past century, contributed to American pikas becoming a focal species...
Resource Type:: Dissertation

ScholarsArchive@OSU

Range-wide abundance and fluctuating asymmetry patterns of sagebrush-obligate passerine birds

Direct and indirect effects of livestock grazing intensity on processes regulating grassland bird populations

Disturbance and roosting ecology of California brown pelicans (Pelecanus occidentalis californicus) on East Sand Island in the Columbia River Estuary

Relative abundance and habitat associations of small mammals in two forest types in southern Oregon

Environmental contaminants and ecology of bald eagles in southcentral Oregon

Combining Disparate Data Sources with Ecosystem and Integrated Models: Case Studies for Improving Management of Protected Species

Bioenergetics-based predator-prey relationships between piscivorous birds and juvenile salmonids in the Columbia River estuary

Hydrologic and vegetation responses associated with restoration of wetlands in the Willamette Valley, Oregon

Nest Success and Cause-Specific Nest Failure of Grassland Passerines Breeding in Prairie Grazed by Livestock

Population Genetics of American Pika (Ochotona princeps) : Investigating Gene Flow and Genetic Diversity Across Multiple, Complex Landscapes

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