Abstracts

Presented by Dana Varner - Email: Dana_Varner@fws.gov

The Rainwater Basin Wetland region (RWB) of Nebraska is the focal point of spring waterfowl migration in the Central Flyway. Currently, over 85% of the historic wetland basins have been drained for agriculture production. Based on population objectives and waterfowl foraging requirements, the Rainwater Basin Joint Venture (RWBJV) estimates 60,000 acres of wetland habitat are needed to support migrating waterfowl, more than double the amount available in a typical year. Currently, the RWBJV partnership does not yet have survey-based, geospatial models that are needed to help prioritize those wetlands and wetland complexes that will best meet the needs of migrating waterfowl. To build these models, a better understanding of the local and landscape level factors that drive habitat selection by the various waterfowl guilds (dabbling ducks, diving ducks, geese) is needed. To help better target conservation efforts, the RWBJV partnership is developing a waterfowl monitoring protocol to be implemented each spring for the next 10 or more years. At sample wetlands, observers measure waterfowl abundance, local wetland conditions, and other variables. Each wetland is surveyed up to three times a week between sunrise and sunset from mid-February to mid-April. From 2017-19, we completed nearly 5,000 surveys on over 500 wetlands in the RWB. Preliminary results indicate that number of ponded hectares had the strongest positive relationship with abundance for dabbling ducks, diving ducks, and geese. Size of the historic footprint and local density of wetlands were also relevant for ducks but not geese. Future modeling efforts will examine effects of vegetation structure, human disturbance, and other variables. The resulting models will be used to develop decision support tools to highlight areas on the landscape the have the greatest probability of use for waterfowl.