California’s rice farms save migrating wild birds with ‘pop-up’ habitat

I had no idea that California was a huge producer of rice until I listened to a fascinating podcast on MIT Technology Review. Tim O’Reilly was talking about data as a public good that could help society as a whole make good decisions, rather than just serving the business interests of tech entrepreneurs. It is fascinating, and well worth listening to.

About halfway through the podcast, he mentioned a project that was using data to show water regulators and scientists when releasing water from dams could be most useful for helping migrating birds. It was only a brief mention, but it intrigued me enough that I wanted to learn more. 

So I dug around and thus found myself deep in some fascinating discussions about California water use, rice farming, migratory birds, and spawning salmon – not to mention citizen scientists who track birds using an app called ebird. It is a story that gives hope for balancing conservation and agriculture through technology, big data, and short-term and comparatively inexpensive answers, and it could transform conservation work in global ecosystems around the world – particularly those areas where land is already intensively used.

In California, rice is grown in the Central Valley, which was once covered in four million acres of wetland fed by snowmelt from the Sierra Mountains. A mecca for insects, birds and fish, it supported tens of millions of birds as they migrated annually along the Pacific Flyway that stretches thousands of miles from Patagonia to the Arctic.

But as people flocked into California, and agriculture grew, California channelled much of that water into levees and irrigation canals, and 95% of the original wetlands disappeared. Agricultural abundance replaced wildlife abundance.

Rice farms were part of that agricultural abundance. In the Sacramento Valley, where 95% of California’s 4.5 billion pounds of rice is grown, there are half a million acres of rice farms, which contribute half a billion dollars to the California economy. 

After their harvest, farmers used to burn their stubble, but in the 1990s, they switched to flooding their fields to rot the stubble. And those flooded fields provided a respite for migrating birds, by mimicking in a small way the wetland conditions that had once existed, and became the foundation for the innovative approach to conservation.

The Nature Conservancy borrowed an idea from Uber and Airbnb – creating ‘pop up’ habitat when and where it was needed – and turned to the California Rice Commission as a partner. BirdReturns, which rolled out as a pilot project in 2013, “pairs birding and farmland management with innovations in big data, crowdsourcing and online auctioneering.” Everyone benefits – the birds, the rice farmers, and bird watchers.

TwoMileProductions, You Tube

To determine specific weeks when birds needed habitat, the Nature Conservancy turned to the Cornell Lab of Ornithology and, with help from NASA, it developed a way to analyze the huge amount of data recorded by the citizen scientists using eBird. To estimate how much additional wetland habitat was needed, they worked with Point Blue Conservation Science to map surface water availability using NASA satellite imagery. 

They mapped the overlay between the bird migration cycles and the agricultural cycle, and then created an online ‘reverse auction’ that allowed farmers to compete for funds in exchange for keeping their lands flooded for the key time. They started with the rice farmers, although they have since reached out to other farmers.

“We could specify the weeks we sought flooded habitat, and even the depth of the resulting water (because some species may need just a few inches, others a foot or more). We evaluated bids based not just on the proposed price of renting the acreage, but also on the conservation value of the potential habitat a given farm might produce, based on proximity to wildlife refuges and so on.” The farmers set the price to flood their fields and BirdReturns chooses the lowest bidders who meet its requirements.

Nobody was entirely sure if the auction idea would work, but the first season was an amazing success. Dozens of farmers offered almost 20,000 acres; 40 farms totalling 10,000 acres were enrolled in the pilot program. The fields were then flooded for four, six or eight weeks, depending on the farmer’s water supplies and farming schedule. “At the end of the first season, BirdReturns fields attracted more than 220,000 migrating birds from 57 species, averaging more than 100 birds per acre.”

Over the next three years, BirdReturns provided more than 40,000 acres of habitat on more than 100 farms, and adapted the program to work on fields planted with other crops including corn and wheat. Permanently protecting those lands would have cost an estimated $200 million.

The Nature Conservancy believes the program can provide as much as 600,000 acres of pop-up wetlands in the next decade, Nature reported in 2018.

“Having a highly dynamic mechanism for creating temporary habitat that can complement the permanent protected areas along the Flyway is only going to grow more important as climates change and we’ll need to help species adapt to the more extreme patterns of drought and deluge expected for California,” says Science for Conservation.

“This project is a case study of how emerging mobile technologies, citizen science, big data analytics, market-based tools, and muddy boots field science can come together to help solve a vexing conservation problem – with a dynamic and adaptable solution that actually can be applied at the hemispheric scale of the Flyway.”

Another innovation in the California rice fields offer good news as well. Native salmon suffer from both the extent to which tributaries have been dammed and from the warming of the Sacramento River.

The Nigiri Project, named for the Japanese sushi dish that combines rice and fish, has brought baby salmon into flooded rice fields during winter to feast on insects until they’re fat and strong enough to migrate down the Sacramento River to the San Francisco Bay and, finally, the ocean, where they spend several years maturing.

Fisheries biologist Jacob Katz believes that rice farms and wildlife can, and should, coexist and that this could be an opportunity to  restore the Central Valley watershed as close as possible to its origins. “You can really finally break the logjam of this mentality of conflict of fish or farms. That’s why rice is really remarkable,” says Katz. “Rice fields can be surrogate wetlands for fish and wildlife.”

He points out that much of the water soaks back into the landscape, recharging depleted aquifers, and thus actually plays a valuable role during drought.

“I’ve always felt that agriculture, instead of being seen as the villain, needs to be seen as a big part of the solution,” Katz says. “It’s not about separating managed lands from the wild. It’s about incorporating the wild into our managed places.”


Migration Moneyball. Nature.

Can flooded rice fields be a solution in California water war? San Francisco Chronicle.

California Farmers Work to Create a Climate Change Buffer for Migratory Water Birds. Inside Climate News.

Paying Farmers to Welcome Birds. New York Times.

BirdReturns. Science for Conservation.

California BirdReturns.

BirdReturns. The Nature Conservancy.

The Nigiri Project.