Freshwater | Terrestrial | Science | Publications & Reports

Waterbird response to variable-timing of drawdown in rice fields after winter-flooding

Kristen Sesser, Monica Iglecia, Matthew Reiter, Khara Strum, Catherine Hickey, Rodd Kelsey, Daniel Skalos

Over 50% of waterbird habitat in the Central Valley of California is provided by flooded agricultural land. Each year non-breeding waterbird habitat decreases in the late winter as flooded agricultural fields are drained after waterfowl hunting season in late-January to prepare for the next crop. This study evaluated a practice called "variable drawdown" that delays removal of water from rice fields to extend the availability of flooded habitat later into February and March in a way that can work for farmers. We found that the staggered drawdown created a mosaic of water depths over a critical time of year for migrating wetland birds and that the value varied in time depending on the types of birds. This is among the first studies showing that a relatively simple practice on farms can successfully extend the availability of waterbird habitat at a time of year when it is needed most and when habitat is highly limited under standard agricultural management practices.