Recent Improvements in Waterbird Numbers and Conditions in the Illinois River Valley

Floodplains of large river systems in the Midwest are often disconnected or pmtially disconnected from flood waters for the benefit of agriculture, urban development, and managed natural resource management. Many of these rivers are drastically altered from their natural state to allow commercial navigation, recreation, and managed flows. In these altered systems, tradeoffs in ecosystemservices exist between connected floodplains and disconnected floodplains. We will present data from two case studies on the Illinois River of central Illinois that illustrate the tradeoffs in biotic communities, especially waterbirds, using floodplains that have been connected hydrologically and those that are isolated behind levees. Wetland birds, fishes, and vegetation all respond differently to floodplain connectivity, and management objectives must be considered carefully prior to restoring hydrologic connections bet.ween floodplains and highly-altered river systems.