Diseases and Parasites of North Dakota Amphibians (SWG T-38-R)

Infectious diseases are a growing concern for the management or conservation of many wildlife species. In amphibians, three sources of disease have been identified as contributing to declines or potential demographic impairment: chytrid fungus, ranavirus, and various helminth parasites. Mass mortality events attributed to ranavirus or chytrid fungus clearly implicate these pathogens as important factors in amphibian declines, but the role of helminths in amphibian population dynamics is less clear. For all known amphibian diseases, outbreaks may be sporadic, with occurrence dependent on other environmental circumstances, challenging our ability to detect and quantify spatial and temporal patterns. Results will provide the first assessment of statewide, geographic and habitat-specific patterns of disease occurrence and risk in a highly sensitive group of animals. We will also determine if some amphibian species, most critically those of Level I conservation concern, are more likely to exhibit higher levels of disease prevalence or parasitic infection, and if disease / parasite prevalence is associated with specific biotic communities, habitat conditions, land uses, ecoregions, or historically documented declines.