Wetlands provides important ecological functions whereas they continue to degrade worldwide. Ishikari River floodplain is one of the critical stopovers for migratory birds. Thousands of migratory birds passes by in spring and fall. Limited knowledge is available for the perspective of conservation prioritization based on regional species diversity. We aimed to identify factors important for duck (Anatidae) habitat and ponds with high conservation value.

We combined secondary (2004) and primary field data (2014) on habitat environment (landscape structure and water chemistry) and duck in 40 ponds. GLMs were developed to examine the relationship between habitat environment, and abundance and α diversity. γ diversity response was simulated to rank the importance of each pond.

The frozen portion of ponds limited habitat use in spring. In fall, surrounding forest% and macrophyte area affected abundance and α diversity positively. Hunting pressure and food resource quality of ponds possibly generated the fall pattern. Gamma diversity was nested with rare species occurring in ponds with high α diversity. Protection of riparian forest and macrophyte cover in ponds with high α diversity could be an effective management strategy.