Rice Lands Provide Vital Waterfowl Habitat

Tod Manning mallard

Each fall, millions of waterfowl migrate from their northern breeding grounds to historical wintering sites in the Mississippi Alluvial Valley (MAV) and along the Gulf Coast. Although the MAV once consisted largely of bottomland hardwood forests and the Gulf Coast was characterized by tall-grass prairie and shallow ponds, these regions have been transformed by agriculture and urbanization. Fortunately, waterfowl have adapted to these changes and now make important use of croplands—notably rice lands—by feeding on grain and natural seeds. However, the future of rice agriculture and the habitat it provides in these regions is uncertain due to challenging markets and limited water supplies.

Active and fallow rice fields along the Gulf Coast receive heavy use by waterfowl and other water birds, but biologists have little information on the exact value of these habitats for wintering birds or the impacts declining rice agriculture will have on their populations. To gain a better understanding of these habitats' value to waterfowl, DU is partnering with Mississippi State University and the Gulf Coast Joint Venture on a multi-year investigation of Gulf Coast rice lands. Under the leadership of MSU doctoral student Joseph Marty and his advisors, Drs. Brian Davis and Rick Kaminski, this research will measure waterfowl use and abundance of seeds in managed rice fields.

Three years into the four-year study, Marty and his colleagues have discovered a 62 percent increase in residual rice (rice seed remaining after harvest) and natural seed abundance between the first harvest in August and the ratoon, or second crop, harvest in November. This contrasts with trends in Mississippi and Arkansas, where shorter growing seasons allow only one rice harvest per year, and where residual rice declines sharply before ducks arrive in November. In addition, Gulf Coast rice lands may contain more than four times the amount of rice and natural seeds than those in the MAV. Marty's work has also documented more than 70 species of water birds using rice lands along the Gulf Coast.

The evidence is clear that Gulf Coast rice lands are rich in grain, natural seeds, and invertebrates, providing vital food resources for wintering waterfowl and other water birds. This research is essential to DU's efforts to raise awareness about the value of rice lands and helps us advocate for policies and programs that will help ensure that these vital habitats remain on these landscapes.