Monitoring Secretive Marsh Birds in Minnesota

Many marsh-dwelling birds are difficult to survey, in large part because of their inconspicuous nature, and also due to the difficulty of accessing their habitats. Avian surveys such as the Breeding Bird Survey and spring Waterfowl Surveys do not adequately monitor these species. Effective conservation planning and habitat management for marshbirds is limited by insufficient information regarding their abundance, distribution, population trends, habitat relationships, and management needs. To address this information gap, we use monitoring programs specifically for marshbirds have been developed across the Midwest using standardized data collection protocols. 

Field surveys were done in the spring of 2016, 2017 and 2018 on a set of predetermined, randomly distributed wetlands statewide. The sites were carefully selected by a rigorous sampling framework to ensure that survey results may be extrapolated to statewide or regional trends. A team of field technicians and volunteer surveyors used a call-playback method designed to maximize the detection of secretive marsh birds. Using a series of silent periods and periods during which the calls of each species are broadcast across the wetland, surveyors recorded the species they detected.