Index Catalog // ScholarsArchive@OSU

Emerging infectious disease in lentic environments : the ecology and biogeography of the amphibian chytrid fungus Batrachochytrium dendrobatidis, with perspectives on water quality, limnology, and chemical contaminants

Creator:: Chestnut, Tara
Abstract:: Biodiversity losses in terrestrial, freshwater, and marine systems are accelerating at a global scale and the most threatened vertebrate taxa are those associated with freshwater habitats. The causes of biodiversity losses are often complex and include synergistic effects of natural and human-induced stressors, such as habitat loss and fragmentation, urbanization,...
Resource Type:: Dissertation
Full Text:: : _____________________________________________________________________ Andrew R. Blaustein Deanna H. Olson Biodiversity losses in terrestrial, freshwater

The Behavioral Responses of Western Toad (Anaxyrus boreas) Larvae to Simultaneous Stressors

Creator:: Reynolds, Emily R.
Abstract:: Animals can be naturally exposed simultaneously to multiple stressors. These include habitat changes, contaminants, diseases, invasive species, parasitism, and predation. Exposure to various combinations of biotic and abiotic stressors may induce behavioral changes that affect the way an individual interacts within its environment.Like other groups of organisms, amphibians are exposed...
Resource Type:: Masters Thesis
Full Text:: Olson, Lindsay Biga, and David Noakes for their helpful advice, support, and comments throughout this

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:: Blaustein, Bruce Menge, Joseph Beatty, Dede Olson, Gordon Reeves, and Douglas Derryberry. During my

The Effects of Nitrate and a Pathogenic Fungus, Batrachochytrium dendrobatidis, on Amphibians

Creator:: Negru, Delia
Abstract:: The current rate of global biodiversity loss and extinctions is unparalleled and a major concern. Freshwater organisms are facing particularly rapid rates of biodiversity loss. Amphibians, which require an aquatic environment for part of their life cycle, are one of the most vulnerable vertebrate groups. Amphibians are experiencing population declines,...
Resource Type:: Masters Thesis
Full Text:: : Dede Olson, Lindsay Biga and Jerri Bartholomew for providing valuable advice and comments on my

The Effects of Host and Pathogen Variation on Infection Dynamics in the Amphibian-Chytrid System

Creator:: Dang, Trang D.
Abstract:: This dissertation uses manipulative experiments to explore amphibian-Bd infection dynamics. Although there has been almost two decades research since the discovery of Bd, many questions still remain regarding what conditions mediate chytridiomycosis virulence. My research shows how certain host and pathogen factors can influence disease virulence. Identifying how host and...
Resource Type:: Dissertation
Full Text:: syndrome in bats(Daszak et al., 2000; Fisher et al., 2012; Olson et al., 2013). Wildlife EIDs pose a

Ontogenetic Shifts in Disease Response in Native and Invasive Anuran Species

Creator:: Urbina Gonzalez, Jenny Cecilia
Abstract:: This dissertation presents a different approach to understanding how amphibians are responding to disease through ontogeny. Although numerous efforts have been conducted to understand host responses to the fungus Batrachochytrium dendrobatidis (Bd), studies have been restricted to distinct developmental stages. This dissertation provides information on host response to Bd across...
Resource Type:: Dissertation
Full Text:: . 2009). Bd has been reported in 516 amphibian species (Olson et al. 2013), and is associated with the

Effects of Diversity on Emerging Infectious Diseases of Amphibians

Creator:: Snyder, Paul W.
Abstract:: Species declines and extinctions have been recorded across taxa as evidence of an ongoing global biodiversity crisis. Amphibians are at the forefront of these declines with nearly one third of amphibian species estimated to be at risk of extinction. While many factors contribute to population declines and extinctions, the role...
Resource Type:: Dissertation
Full Text:: . N. Kagley, R. Olson, P. Reno, and J. E. Stein. 1998. Effect of pollution on fish diseases

All hosts are not created equal : variation in amphibian responses to an emerging fungal pathogen and why it matters

Creator:: Gervasi, Stephanie S.
Abstract:: Emerging infectious diseases are increasing globally and are a threat to human, wildlife, and ecosystem health. The emerging fungal pathogen, Batrachochytrium dendrobatidis (Bd), or amphibian chytrid fungus, is associated with worldwide amphibian population declines and extinctions. Bd has been found on every continent where amphibians exist and has been documented...
Resource Type:: Dissertation
Full Text:: different perspective. Although not technically part of my committee, Dede Olson has been a valuable

Disentangling the Biotic and Abiotic Drivers of the Amphibian Disease Chytridiomycosis

Creator:: Bradley, Paul W.
Abstract:: The ongoing worldwide loss of biodiversity has been described as a "biodiversity crisis," "the Anthropocene defaunation," and alternatively "an extinction spasm." More recently, many scientists have come to the conclusion that we are witnesses to Earth's sixth major mass extinction event, which has the potential to fundamentally alter basic ecological...
Resource Type:: Dissertation
Full Text:: . Additionally, I am very appreciative of Dr. Deanna Olson (Oregon State University) who has been a

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:: , E. Brodie, Jr., T. Farrell, D. Formanowicz, Jr., R. O'Hara, D. Olson, B. Tissot, and especially A

The Role of Emerging Pathogens in Amphibian Population Declines : Experimental Evidence

Creator:: Hambalek, Natalie M.
Abstract:: Rapid rates of biodiversity loss have supported the notion that Earth is experiencing a sixth major extinction event. The causes of worldwide biodiversity loss are multifaceted and context dependent. One of the most prominent groups experiencing population declines and extinctions are amphibians. Several pathogens and their associated diseases are especially...
Resource Type:: Masters Thesis
Full Text:: in the beginning of my graduate work. I am grateful for Dede Olson for her helpful advice regarding

Complexity in host-pathogen dynamics : dispersal uncertainties, metapopulation persistence and the role of a changing climate

Creator:: Xie, Yang
Abstract:: Emerging infectious diseases impact both human and wildlife populations. Infectious agents, in particular the aquatic fungus Batrachochytrium dendrobatidis (chytrid), have an influential role in driving global amphibian population declines. The emergence of the chytrid fungus has aspects of both geographic spread as well as climate shifts altering environmental conditions and...
Resource Type:: Dissertation
Full Text:: , McCallum 2007, Crawford et al. 2010, Olson et al. 2013)). Chytrid belongs to the phylum

Host parasite relationships between deer mice (Peromyscus maniculatus) and their eimerian parasites (protozoa)

Creator:: Fuller, Claire A.
Resource Type:: Dissertation
Full Text:: and E. delicata and their deer mouse host, Peromyscus maniculatus. Deer mice shed up to 106 E

The effects of multiple pathogens on amphibians in the Pacific Northwest

Creator:: Romansic, John M.
Abstract:: The earth is undergoing a “biodiversity crisis” characterized by loss of populations, species, genetic diversity, and ecosystem services. Part of this crisis consists of population declines, extinctions, and increased incidence of deformities in amphibians. It is unknown whether deformities contribute to these declines. Many cases of population declines in amphibians...
Resource Type:: Dissertation
Full Text:: encouragement. Dede Olson and David Wake and the IRCEB amphibian disease research consortium, especially

The effects of parasites on host behavior : who benefits?

Creator:: Lefcort, Hugh G.
Abstract:: Some parasites may modify the behavior of their hosts. Altered behaviors may: 1) benefit the host in that they defend against the pathogen, 2) benefit the pathogen and represent manipulations of the host response, and 3) benefit neither the host or the pathogen and simply be a product of the...
Resource Type:: Dissertation
Full Text:: season (weeks); (E) size (total length in mm); and (F) altitude of capture (m). These data were

Environmental influences on host-pathogen dynamics of the amphibian chytrid fungus

Creator:: Buck, Julia C.
Abstract:: The causes of the global biodiversity crisis are varied and complex. Anthropogenic threats may act in isolation, or interact additively or synergistically with each other or with natural stressors to affect sensitive taxa. The recent emergence of many infectious diseases in wildlife has brought attention to the role of disease...
Resource Type:: Dissertation

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:: maTheir'' RedaCted for privacy Chairman of Department of Z.. ogy Redacted for privacy Dean of Grad a e

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:: ., Olson 1989). Another possible mechanism that may facilitate synchronous metamorphosis in the field

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:: experiments. Deanna Olson contributed financially to this project and with experimental design. Chapter

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:: and Olson 1990; Menge and Sutherland 1987; Connell and Sousa 1983; Andrewartha and Birch 1954

Effects of pesticides on amphibians with special reference to the pyrethroidinsecticide, cypermethrin

Creator:: Biga, Lindsay M.
Abstract:: Pollution by pesticides is a ubiquitous concern for wildlife. The effects of pesticides are especially concerning in aquatic environments, which are particularly vulnerable as they have several exposure routes for the influx of chemicals. These effects are of particular concern as biodiversity loss reaches unprecedented rates. This includes recent declines...
Resource Type:: Dissertation
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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:: Beatty and Dede Olson have truly provided me with wonderful advice, funding at times, and many field

Experimental analysis of competition between desert rodents in Oregon

Creator:: Schoffelen, Emile
Resource Type:: Masters Thesis

Ultraviolet radiation as an environmental stressor of amphibians

Creator:: Bancroft, Betsy A.
Abstract:: My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB...
Resource Type:: Dissertation
Full Text:: species observed and transect information for each field site ………………………………………………………………………. 174 E

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

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
Full Text:: of my research efforts. I would also like mention my appreciation to Dede Olson for providing help

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