Rice fields provide a welcome for shorebirds

With most of California’s natural wetlands gone, millions of migrating waterbirds now depend on the state’s vast rice fields. This fall, 70 rice farmers in the northern Central Valley began making their land more bird-friendly, thanks to a $2.68-million US Department of Agriculture Natural Resources Conservation Service (USDA NRCS) pilot project. “Rice fields already provide excellent wildlife habitat, and a little more effort by growers will make a lot more habitat”, says Alan Forkey, NRCS Assistant State Conservationist (Davis, CA).

The Central Valley is a key part of the migratory Pacific Flyway, which stretches from Alaska to Patagonia, and provides resting, overwintering, and breeding sites for migrating birds. Numerous species of migrating waterfowl and shorebirds, including the highly imperiled long-billed curlew (Numenius americanus), visit California’s rice fields. Shorebird populations are declining globally, and the northern Central Valley has been designated as a “Shorebird Site of International Importance” by the Western Hemisphere Shorebird Reserve Network Council (Manomet, MA).

As part of the national NRCS Migratory Bird Habitat Initiative, the California rice-field project entails paying farmers to implement recommended conservation practices. “Producers never get reimbursed for 100% of the costs and generally fund about 50% of them on their own”, Forkey explains. A popular conservation practice involves creating wetland habitat where irrigation water enters the field; in addition to establishing brood ponds for birds, this practice warms the chilly irrigation water and consequently boosts rice yields. “We were surprised at how many landowners signed up for this”, says Forkey. “[So far] we have ~63 hectares of brood ponds.”

Farmers are also building 75-square-meter “loafing islands” in their fields. “Rice will grow around them, providing a protected plateau for nesting”, according to Paul Buttner, Environmental Affairs Manager for the California Rice Commission (Sacramento, CA), which partnered with the NRCS on this project. Additional nesting habitat will be provided by flattening the tops of the berms that control water flow through the fields. These berms will be graded to provide wading birds with a range of foraging depths.

The participating farmers account for about 5% of the rice fields statewide. “If we can show that ‘growing birds’ contributes to the bottom line just like growing rice, more farmers may join the habitat business”, Buttner predicts.

Frontiers in Ecology and the Environment, 2011