Flooded grasslands and savannas is a terrestrial biome of the World Wide Fund for Nature (WWF) biogeographical system, consisting of large expanses or complexes of flooded grasslands. These areas support numerous plants and animals adapted to the unique hydrologic regimes and soil conditions. Large congregations of migratory and resident waterbirds may be found in these regions. The relative importance of these habitat types for these birds as well as more migratory animals typically varies, as the availability of water and productivity annually and seasonally shifts among complexes of smaller and larger wetlands throughout a region.