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...
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...
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...
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...
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,...
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...
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...
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,...
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...
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...