A California Wetland Program’s Flood of New Funding Lifts Hopes for Shorebirds

When John Brennan makes the short drive from his home in Davis, California, to the rice farms he manages along the Sacramento River, he always brings a laminated guide to the region’s shorebirds and waterfowl. These creatures have long been of interest to Brennan and there are few better places to see a dozen or more species at once than in a flooded rice paddy. He pulls his Ford pickup to the side of a dirt road bisecting the property and points at a winged visitor touching down in the shallow water. 

“That’s a Long-billed Curlew that just came in—that’s like the prize of the floodplain,” Brennan says, handing his binoculars to me. It’s September, when many migratory birds are returning south from their Arctic and boreal breeding grounds, and Brennan points out American Avocets, White-faced Ibises, Long-billed Dowitchers, American White Pelicans, Snow Geese, and Western Sandpipers. 

Brennan has been working with growers for three decades and today he manages thousands of acres for farms including Robbins Rice Company and Davis Ranches. While rice remains his top crop, birds and wetlands have become an important side hustle—not just for Brennan but for scores of Central Valley farmers enrolled in BirdReturns, a program that pays them to flood their land, creating temporary wetlands when and where birds need them most.  

For millennia seasonal wetlands dotted California’s Central Valley, providing crucial habitat for millions of shorebirds to rest and refuel during migration. But as farms and towns have taken over the landscape, nearly all those shallow, ephemeral water bodies have disappeared, leaving avian migrants with scant options for pit stops. With shorebirds rapidly declining along the Pacific Flyway, conservationists and landowners have joined forces to help turn the tide. Launched in 2014, BirdReturns runs via reverse auctions: Farmers offer up acreage and name the price. If it’s right, they get cash in exchange for spreading a thin layer of water across their land, where birds can forage on aquatic invertebrates and other foods. Since its inception, the program—jointly run by Audubon California, The Nature Conservancy, and Point Blue Conservation Science—has paid more than 100 farmers a total of $2 million to flood 60,000 acres throughout the Sacramento and San Joaquin valleys. Buoyed by a recent $15 million grant from the state, the program is poised to greatly expand its reach.

Around California, a push to revitalize semiaquatic habitat is accelerating. Many riverside floodplains, tidal marshes, and other wetlands are being permanently restored to a natural state. In the agriculturally productive Central Valley, however, dual land-use programs like BirdReturns often make the most economic sense by making space for wildlife without excluding farming.

But more work must be done, and faster. There is evidence that shorebirds in the Central Valley don’t have enough to eat most years, and their populations are declining across North America. As they try to turn things around, scientists know that every patch of habitat along the Pacific Flyway counts.

Working With Landowners

Historically, the Sacramento and San Joaquin rivers—the major waterways that course through the Central Valley—flooded almost every year, inundating several million acres. This flooding cycle created a phenomenal seasonal wetland complex that supported millions of shorebirds, waterfowl, and migrating Chinook salmon, as well as large mammals like grizzly bears, elk, and mountain lions. 

In the past 150 years, however, nearly all those wetlands were cleared and cultivated or built upon. Dams and levees were constructed to contain rivers and keep the land dry where it used to flood. The Central Valley became a global agricultural powerhouse, but its biodiversity is a shadow of its past glory. Roughly 200,000 acres of that floodplain system remains. The valley’s bears and cougars are mostly gone, its salmon runs have dwindled, and, while waterfowl remain in large numbers, shorebird activity is declining. 

This lopsided land-use model is changing as multiple-benefit approaches gain popularity. Brennan enrolled when BirdReturns began, and he floods hundreds of acres each year. Prior to his participation, shorebirds were occasional visitors and little more than background noise to the daily tasks of farming. Today, he says, flooded fields may be “covered in birds” for weeks. 

While waterfowl and waders benefit from BirdReturns, it was designed primarily for shorebirds imperiled by long-term habitat loss. The program focuses on providing spring and late-summer habitat, with the latter representing a weak seasonal link in wetland availability for some two dozen shorebird species that pass through the region earlier than many other fall migrants. “That’s a big habitat deficit we’re seeing across the valley—that summer, semi-permanent wetland habitat,” says Xerónimo Castañeda, Audubon California’s program director for working lands.

The practice is good for growers, too. Brennan says rice farms benefit from periodic rotations out of production—roughly once every five years. By using these down-seasons to create wetlands, farmers can help birds and make a little money they wouldn’t have otherwise. Drought years—because they sometimes mean mandatory idling of rice paddies—can offer similar opportunities.

For growers, though, the money is hardly free. “It’s another job,” Brennan says, explaining that managing water for birds requires farmers to work outside of the standard growing season. Flooding land in a way that helps shorebirds, he adds, involves closely monitoring its depth and rates of seepage and evaporation. While ducks and geese like water deep enough to swim in, shorebirds prefer wetlands where the water is barely beak-deep. 

To maximize the benefits for birds, The Nature Conservancy California hosts workshops to coach landowners in managing their property to support avian visitors. The organization also conducts compliance monitoring of field sites to make sure birds are getting what they need from the partnerships. For instance, Sandhill Cranes need roost sites that encompass at least 40 acres covered with between three and nine inches of water. The Nature Conservancy is flooding strategic locations at the periphery of known crane foraging territory in an effort to expand the birds’ winter range, says Greg Golet, a senior scientist with the organization’s water program.

Audubon, for its part, is working mostly with duck clubs that typically flood their land during hunting season in the fall and winter but, for a price, will keep it covered with a few inches of water in the so-called shoulder seasons. Point Blue, meanwhile, uses data from bird surveys and satellite maps from NASA to assess prior to enrollment, each applicant’s property and its potential benefits for birds based on a parcel’s size, cost, and proximity to other habitat. Some properties don’t make the cut, no matter how low the price. “We want to make sure we’re getting the most bang for our buck with these partnerships,” says Matt Reiter, a research director with Point Blue’s Pacific Coast and Central Valley Group. 

Other incentive-based flooding programs in the Central Valley, such as Bid4Birds—a California Ricelands Waterbird Foundation program modeled on BirdReturns—and the Natural Resources Conservation Service’s Waterbird Habitat Enhancement Program, are adding to the region’s wetland pool.

Closing the Gap

Because shorebirds migrate across much of the globe, they expose themselves to potential impacts in many regions, habitats, and nations. Somewhere in this network of resting and refueling sites, something is wrong.

Globally, shorebird numbers are trending precipitously down. Last year scientists reported that 26 of 28 North American shorebird species they studied were declining. Evidently more than half of those species had crashed by more than 50 percent over nearly 40 years, and 18 species showed accelerating downward trajectories. 

A variety of factors are believed to be driving the declines, including pollution, disturbance at stopover sites, hunting, and poaching. Changes to wetland form and function are also likely at play. In coastal zones, rising sea levels are submerging and eroding shorebird feeding grounds. Development—including new homes in the Central Valley—is taking its toll, as is water scarcity. In the Klamath River basin, for instance, another critical stopover for birds on the California-Oregon border, wetlands have been chronically short of water in the past decade of repeated droughts. “The more it’s drying up, the more important it is to provide habitat in the Central Valley,” Reiter says.  

While protection and enhancement of Central Valley wetlands beginning in the 1990s helped boost waterfowl populations, data suggest that shorebirds that stop over there are continuing to decline globally. Indeed, Reiter says prompting a comparable jump in shorebird numbers through increased flooding could be more challenging, for multiple reasons. For one thing, shorebirds tend to have much lower fecundity—fewer eggs per clutch—than ducks and geese, Reiter says. Also, the fact that ducks and geese have a recreational value that shorebirds don’t is a clear survival advantage. “There’s a vested interest in getting waterfowl populations to increase,” he says. “There’s a hunting constituency that has been a hugely important component of waterfowl conservation.” 

Unfortunately, the remaining habitat beside the Sacramento and San Joaquin Rivers, as valuable as it is, has an uncertain future. Research from The Nature Conservancy and Point Blue shows sharp declines in seasonal wetland coverage during recent dry years—gaps that are likely to widen as the Earth warms and droughts worsen. 

BirdReturns is now in a better position than ever to help close those gaps. Thanks to the $15 million grant from the California Department of Fish and Wildlife, the program is abruptly flush with cash. The money was primarily split between Audubon and The Nature Conservancy, with a smaller piece dedicated to Point Blue’s research and modeling. The funds must be spent by the end of 2026.

“It’s a big relief,” says Castañeda. For a program accustomed to small trickles of funding, the deluge means fewer last-minute negotiations with landowners and more time to strategize, plan, and, most importantly, direct valuable river water toward the most optimal properties. 

While rebuilding populations of these global voyagers is no small undertaking, the BirdReturns partners agree that the first step toward any recovery is more flooded fields. Parcel by parcel, the benefits add up.

A version of this story originally ran in the Spring 2024 issue as “Meals on Fields.” To receive our print magazine, become a member by making a donation today.