Evaluation of Integrated Waterbird Management and Monitoring Program Survey Techniques to Assess Waterbird Abundance

A wide variety of survey designs and protocols are used to monitor waterfowl and other wetland-dependent bird (collectively, waterbird) abundance during migration and winter (hereafter, non-breeding period). Biologists from state and federal agencies, non-government conservation organizations, and universities use waterbird monitoring data to track trends in site use over time, index local population sizes, provide outreach to the general public, evaluate management or conservation actions, and myriad other purposes. However, inconsistent methodologies and inadequate design relative to survey objectives or science needs often reduce the usefulness of waterbird monitoring data. The Integrated Waterbird Management and Monitoring Program (IWMM) represents a collaboration between many partners to provide a framework for standardized data collection, data management, and manipulation of decision support tools through an interactive online portal to assist habitat managers and decision makers in non-breeding habitat conservation and delivery. We evaluated the IWMM waterbird monitoring protocol by comparing seasonal duck use-day estimates and peak abundances derived from ground surveys to estimates based on aerial surveys during 2010­–2016 at portions of Clarence Cannon, Great River, and Two Rivers National Wildlife Refuges. Aerial surveys were conducted by the Illinois Natural History Survey and corrected for detection probability and count bias using results from an ongoing research project. Ground surveys were conducted during the same week as aerial surveys by the Fish and Wildlife Service or cooperators. We will present results from this evaluation, model factors (e.g., observer, vegetation cover, weather conditions) affecting waterbird surveys, and make recommendations for future implementation of the IWMM survey protocol.