Date of Award
Master of Science
Historically, management for migratory waterfowl was focused around providing hunting opportunity each fall. More recently habitat during spring migration has received attention as a potentially limiting factor for some species of waterfowl, considering the carry-over effects that have been observed in both capital and income breeders. Habitat needs have been compounded by the flashy flood events that now occur in the highly modified landscape. The discovery of carry-over effects has led to an increase in habitat management actions and a diversification of available management strategies. In my study I hoped to identify the best management strategies for spring migratory waterfowl. I also wanted to identify how quickly waterfowl can respond to flood events. In 2012 and 2013, I examined the effect of habitat management on dabbling duck behavior and distribution during spring migration in southwest Indiana. I investigated three management options for wetlands: active management, passive management, and agricultural food plots. Actively managed wetlands are wetlands where the hydrology is managed and controlled. In passively managed wetlands and agricultural food plots; the hydrology is provided naturally. I surveyed both duck behavior and abundance on 14 wetlands on the Patoka River National Wildlife Refuge and Management Area. I also surveyed short-lived wetlands to determine the response rate of waterfowl to inundation following rain events. The agricultural food plot areas had the lowest estimates of food availability followed by the actively managed areas with the passive managed wetlands having the highest estimate. Waterfowl abundances were highest on the actively managed wetlands with the food plots coming in second and the passive wetlands coming in a distant third. The passive wetlands had the highest proportions of time spent feeding followed by the active and food plot wetlands. Dabbling ducks were not distributing themselves relative to food density but are feeding in the highest proportions in these areas. Waterfowl use was recorded less than 24 hours after inundation on 14 of 21 short-lived wetlands. Short-lived wetlands may be important to migratory waterfowl. Conservation prioritization of passively managed areas would provide larger areas for dabbling ducks to feed, but active management provides habitat regardless of climatic variability. Moving forward, wetland complexes encompassing diverse wetland management approaches would be the best option for spring migrating waterfowl as these complexes can provide high quality habitats and buffer against uncontrollable climactic conditions.
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