Cooperative Fish and Wildlife Research Units Program: Idaho
Education, Research and Technical Assistance for Managing Our Natural Resources

Light-footed Ridgway’s rails are a federally threatened species endemic to coastal areas of southern California. The species’ recovery plan has explicit recovery goals detailing population sizes needed for downlisting. Yet we lack a meaningful and statistically defensible monitoring and assessment framework to assess range-wide populations relative to recovery goals. We used historical occurrence data and spatially explicit models of potential habitat to develop a spatially-stratified sampling frame covering key rail habitats across their range. We also developed a detailed stochastic simulation model to mimic sampling and simulate call-broadcast data under varying rail densities and response rates, and differing levels of spatial and temporal replication of sampling. Using stochastic simulation, we are also simulating 6 sampling strategies that represent different approaches for allocating sampling efforts spatially amongst sampling strata and multiple methods for probabilistically selecting areas to sample within each stratum. Results of our simulation study will inform field application of range-wide monitoring and survey efforts for this rare bird and provide partners with critical information about appropriate sampling strategies and efforts needed to reliably track recovery of Light-footed Ridgway’s Rails across their range. Collectively this work will also provide the first range-wide, spatially explicit monitoring and assessment framework for any species of secretive marsh bird.