Willamette Valley Mid-Level Monitoring Area (ARMI)

Introduced fish and bullfrogs can be detrimental to native amphibians and are difficult or impossible to eradicate.  Despite their detrimental effects, even sensitive native amphibians can sometimes be found coexisting with these species and we want to know how managers can promote this.

We will determine what factors are associated with the long term persistence of native amphibians at sites with introduced fish or bullfrogs.  What factors promote coexistence when we can't eradicate the introduced species?  This project will also monitor the status of amphibians on DOI lands in the Willamette Valley as part of the USGS Amphibian Research and Monitoring Initiative.

We have completed 3 years of monitoring in this long-term study. We have estimated the occupancy rate of native amphibians and introduced fish and bullfrogs.  We have fine-tuned the models we will use to analyze the long term data by determining factors that affect our ability to detect populations that are present.

Long-term, we will be able to estimate the probability of local extinction at sites with various attributes.  We will get information on site characteristics that are associated with coexistence of native amphibians with introduced species.

	Contact: Michael J. Adams USGS, Forest and Rangeland Ecosystem Science Center 3200 SW Jefferson Way Corvallis, OR 97331 Michael_Adams@usgs.gov Website: http://armi.usgs.gov