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Filtering by: Creator Kruse, Travis M. Remove constraint Creator: Kruse, Travis M. Advisor Blaustein, Andrew R. Remove constraint Advisor: Blaustein, Andrew R.

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  • Unpalatability as an antipredator defense in anuran larvae

    Creator:
    Peterson, Jeffrey A.
    Abstract:
    The tadpoles of several anuran species with groupforming larvae are relatively unpalatable to many of their potential predators. To more fully understand the role of palatability and its relationship to group formation as an antipredator defense in anuran amphibian larvae, I investigated the palatabilities of the larvae of three species...
    Resource Type:
    Masters Thesis
    Full Text:
    -limited predators (Caldwell et al., 1980; Brodie and Formanowicz, 1983; Travis et al., 1984; Crump, 1984

  • The effects of predation on anuran metamorphosis

    Creator:
    DeVito, Jill
    Abstract:
    Many organisms with complex life cycles undergo transition periods associated with increased vulnerability to predation. Several evolutionary adaptations have been proposed as antipredator defenses for organisms during risky transition periods. These include: shortening of the transition period, parental care, cryptic coloration, and synchrony of risky transitions with large numbers of...
    Resource Type:
    Masters Thesis
    Full Text:
    , located in the Oregon Cascade Mountains (Linn County, elevation 1220 m). T. sirtalis feed on larval and

  • An investigation of the alarm response in anuran amphibian larvae

    Creator:
    Hews, Diana K.
    Abstract:
    The results of my research suggest that tadpoles of the Western toad (Bufo boreas) and the Cascades frog (Rana cascadae) display an alarm response to chemicals from injured conspecific tadpoles. Furthermore, results suggest that the Bufo boreas alarm response can be elicited by a natural predator when it feeds on...
    Resource Type:
    Masters Thesis
    Full Text:
    boreas tadpoles were collected from Lost Lake (1219 m), Linn County. All Bufo tadpoles used in extracts

  • Ecological aspects of kin discriminating behavior with implications of functional value

    Creator:
    Hokit, D. Grant
    Abstract:
    To assess the context dependence of kin discriminating behavior, I examined kin-biased aggregation behavior in tadpoles of R. cascadae in different ecological conditions. I manipulated food distribution, predator presence, thermal heterogeneity, and relatedness in a multifactorial mesocosm experiment. All four factors interacted to influence tadpole dispersion. My results suggest that...
    Resource Type:
    Dissertation
    Full Text:
    OBSERVATIONS Study Site and Methods Our study site was a subalpine meadow (elevation = 2300 m) located 40

  • The effects of pathogens, UV-B radiation, and introduced species on amphibians in the Pacific Northwest

    Creator:
    Kiesecker, Joseph Michael
    Abstract:
    I examined two amphibian communities to assess factors that may impact amphibian biodiversity. The results suggest that the potential factors which influence the maintenance of amphibian biodiversity are multi-faceted and thus, attempts to understand these factors must reflect these complexities. I investigated factors that influenced the susceptibility of western toad...
    Resource Type:
    Dissertation
    Full Text:
    species on amphibians in the Pacific Northwest AN ABSTRACT OF THE THESIS OF Joseph M. Kiesecker for

  • Multiple stressors and amphibian population declines

    Creator:
    Hatch, Audrey C.
    Abstract:
    In the past decade, declines in amphibian populations have captured scientific and popular interest. The causes of the declines are likely to be complex and involve interactions between several environmental stressors. Using multifactorial experiments, I investigated the combined effects of several anthropogenic stressors on developing amphibians in Oregon, USA. In...
    Resource Type:
    Dissertation
    Full Text:
    2001, Dunson and Travis 1991). iNTERACTIONS OF ABIOTIC STRESSORS Introduction Several studies of

  • Cannibalism in larvae of the long-toed salamander, Ambystoma macrodactylum

    Creator:
    Wildy, Erica Lynn
    Abstract:
    Predator-prey interactions have historically been studied to explain patterns of organization observed in populations and communities. They have also been important in understanding the evolution of antipredator responses in prey and counterstrategies in predators. Despite the breadth of knowledge that exists for heterospecific interactions, relatively few studies have investigated the...
    Resource Type:
    Dissertation

  • Indirect effects of ultraviolet-B radiation on larval amphibians as mediated by food quality and trophic interactions

    Creator:
    Scheessele, Erin A.
    Abstract:
    Ultraviolet-B radiation (UVB) is an abiotic stressor in both terrestrial and aquatic systems. The stratospheric ozone layer, depleted due to anthropogenic activities and the cause of elevated UVB at earth's surface over the last four decades, is predicted to recover by 2065. However, UVB levels in aquatic systems may continue...
    Resource Type:
    Dissertation

  • Host-pathogen dynamics in a changing environment : susceptibility of amphibians to an emerging infectious disease

    Creator:
    Searle, Catherine L.
    Abstract:
    Infectious diseases are a growing concern for both humans and wildlife. The negative effects of infectious disease have been exemplified by the recent global amphibian population declines associated with disease outbreaks. Although multiple pathogens and factors play a role in these declines, the aquatic fungal pathogen, Batrachochytrium dendrobatidis (Bd), has...
    Resource Type:
    Dissertation
    Full Text:
    Phillipsen, Jarod Sapp, Nick Baker, Alison Iles, Kaitlin Bonner, Travis Godkin, Chris Friesen, Kate Boersma