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Filtering by: Creator Hixon, Mark A. (Mark Anthony), 1951- Remove constraint Creator: Hixon, Mark A. (Mark Anthony), 1951- Academic Affiliation Fisheries and Wildlife Remove constraint Academic Affiliation: Fisheries and Wildlife Degree Level Doctoral Remove constraint Degree Level: Doctoral

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  • Description and analysis of dietary preference of lingcod in the nearshore zone, Oregon

    Creator:
    Tinus, Craig A.
    Abstract:
    The lingcod (Ophiodon elongatus) is an important groundfish species in both recreational and commercial fisheries of the Northeastern Pacific. It is a large, fast-growing, generalist predator of invertebrates and fishes. In response to concerns that lingcod may limit populations of rockfishes (Sebastes spp.), I compared the diets of 375 adult...
    Resource Type:
    Dissertation
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    became this dissertation. Over many years, Mark Hixon and Mark Carr contributed much to my

  • Local weather, regional climate, and population dynamics of northern spotted owls in Washington and Oregon

    Creator:
    Glenn, Elizabeth M.
    Abstract:
    Since the early 1990s, declines in northern spotted owl (Strix occidentalis caurina) populations have been documented through extensive field surveys and range-wide demographic analyses. Although loss of late-successional forest has been credited as the primary cause for spotted owl population declines, environmental variation has also been shown to influence vital...
    Resource Type:
    Dissertation
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    thank my major advisor, Robert Anthony, for his guidance and for encouraging me to do a PhD despite

  • Life-history organization of herring (Clupea harengus pallasi) in the northeast Pacific

    Creator:
    Aleaziz, Farzad
    Abstract:
    The distribution of herring (Clupea harengus pallasi) in the Northeast Pacific extends from southern California to northern Alaska. Studies on variation in herring life-history are limited to local characteristics and recruitment populations or relatively restricted regions of the Northeast Pacific. In this study I assessed herring life-history patterns and recruitment...
    Resource Type:
    Dissertation
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    and have a longer duration of spawning than herring from northerly sites. There were significant

  • Feeding Ecology and Growth of Juvenile Chinook Salmon (Oncorhynchus tshawytscha) During Early Marine Residence

    Creator:
    Litz, Marisa Norma Chantal
    Abstract:
    The early marine phase following freshwater emigration has been identified as a critical period in salmonid (Oncorhynchus spp.) life history, characterized by high but variable mortality. Consistent with the “growth-mortality” and “bigger-is-better” hypotheses, at least some of the mortality during the critical period appears to be size-dependent – with smaller...
    Resource Type:
    Dissertation
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    : ______________________________________________________ Jessica A. Miller The early marine phase following freshwater emigration has been

  • Population ecology of the Columbian white-tailed deer

    Creator:
    Gavin, Thomas Alan
    Abstract:
    A population of Columbian white-tailed deer (CWTD) was studied on a refuge (790 ha) in southwestern Washington during 1972-77. Quality of habitat was considered good for these deer and total population size remained between 164-230 as determined by mark-recapture methods during November. Population size declined significantly between the winters of...
    Resource Type:
    Dissertation
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    . Abstract approved: Redacted for privacy E. Chadles Meslow A population of Columbian white-tailed deer

  • 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
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    represents a complex disturbance, grazing intensity largely determines the effects of grazing on vegetation

  • A macroscopic to microscopic study of the effects of barotrauma and the potential for long-term survival in Pacific rockfish

    Creator:
    Pribyl, Alena L.
    Abstract:
    Depleted species of rockfish (Sebastes spp.) from the Northeast Pacific experience high discard mortality due to "barotrauma," induced from the rapid change in pressure during capture. Research suggests rockfish have the potential to survive barotrauma if immediately recompressed, but the potential for long-term recovery is unknown. In this project, we...
    Resource Type:
    Dissertation
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    . Title: A Macroscopic to Microscopic Study of the Effects of Barotrauma and the Potential for Long

  • Factors affecting the abundance of fall chinook salmon in the Columbia River

    Creator:
    Van Hyning, Jack M.
    Abstract:
    A study of the population ecology of Columbia River fall chinook salmon, Oncorhynchus tshawytscha (Walbaum), was made in an attempt to determine the cause of a serious decline in this run which occurred in the early 1950's. Fluctuations in abundance of major salmon runs the North Pacific were examined to...
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    Dissertation
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    tagged: A in the Grays Harbor area, May -June 1951 (97); B in the Columbia and Grays Harbor areas, 1958

  • 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...
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    Dissertation
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    californianus), one of the most endangered birds in the world, is a remarkable example of how reintroduction

  • Status and habitat use of Columbian white-tailed deer in Douglas County, Oregon

    Creator:
    Smith, Winston Paul
    Abstract:
    A study conducted May 1978-December 1980 determined that the present geographic range of Columbian white-tailed deer, Odocoileus virginianus leucurus, (CWTD) in Douglas County, Oregon encompassed 1199km2. The area was predominately a Quercus woodland community, typical of the Interior Valley Zone of western Oregon. The CWTD distribution was not contiguous throughout...
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    Dissertation
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    . Coblentz A study conducted May 1978-December 1980 determined that the pre- sent geographic range of