flying over flooded rice fields in Colusa, California.
Migrating birds flying over flooded rice fields in Colusa, California. © Drew Kelly/TNC

Stories in California

Migration Moneyball

Data science and innovative economics are helping The Nature Conservancy build a brighter future for migratory birds.

Migratory birds are nature’s marathon runners. They trek between their summer and winter homes each year, some flying to the end of the earth and back again. Certain species can travel for days without eating or sleeping—but eventually they all need a place to rest and refuel.

For the birds that migrate along the Pacific Flyway, which stretches thousands of miles from the Arctic to Patagonia, California’s Central Valley was once the ideal pit stop. Its lush wetland terrain supported tens of millions of birds on their annual pilgrimage. But today, more than 95 percent of those wetlands have disappeared, lost to farmland, urban sprawl, an overburdened water system and extreme drought.

Climate change is putting pressure on migratory species, shifting and compacting their ranges. A 2014 study found 90 percent of North American shorebirds surveyed, most of which migrate along the Pacific coast, were expected to face an increased risk of extinction due to climate-driven threats.

“Birds are under a lot of stress,” says Mark Reynolds, lead scientist for The Nature Conservancy’s migratory bird program. “They’re flying around looking for habitat and mostly not finding it.”

To protect birds that are always on the move, The Nature Conservancy looked to pioneers of the sharing economy, such as Uber, Airbnb and Zipcar. If short-term deals can work for cars and condos, why couldn’t it work for conservation?

With this model in mind, the Conservancy rolled out an innovative program called BirdReturns in 2013. Combining images from NASA satellites, data from citizen scientists and land rented from local rice farmers, the program provides pop-up habitats when and where birds need it most.

Read on to learn how The Nature Conservancy is transforming the Central Valley’s landscape with this game-changing conservation approach.

Sandhill cranes in the Central Valley.
An Oasis in the Valley Sandhill cranes in the Central Valley. © All Rights

An Oasis in the Valley

Big data powers precision conservation work in California’s Central Valley.

Birds are natural-born navigators. Like the first sailors, they find their way north and south by looking to the stars or tracking their progress against the setting sun. But they aren’t only focused on the destination. All along the way, birds use their well-honed senses to find the resources they need to sustain themselves on their annual sojourn.

“They’re looking for wetlands, places that provide food and shelter,” says Paul Spraycar, senior project director for The Nature Conservancy’s California water program. “And they’ll move around the entire valley looking for the very best conditions.”

While birds only need a few inches of water to help them recuperate, those ideal rest areas are getting harder to find, says Mark Reynolds, lead scientist for The Nature Conservancy’s migratory bird program. Climate change is eroding the coastal areas shorebirds rely on, and drought is shrinking already diminished wetland habitats.

“A lot of things are changing for them along the flyway—and not for the better,” Reynolds says.

In the 1850s, the Central Valley offered 4 million acres of wetland habitat, enough to support tens of millions of birds. Today, only 250,000 acres of wetland remain, contained within a relatively small—but critical—number of refuges, protected areas and managed wetlands. And the landscape is constantly changing.

“Birds are seeking out habitat in different places each year,” says Spraycar. “And the availability of that habitat is also changing every year, according to rainfall, farming, economics and how the overall water system is managed.”

While birds only need a few inches of water to help them recuperate, those ideal rest areas are getting harder to find.

Migratory Birds Lead Scientist, The Nature Conservancy

This fluid environment creates a challenge for conservationists. To provide temporary habitats in the right place and at the right time, The Nature Conservancy needed a way to predict migration paths and determine where birds would gather each season.

“We knew from the very beginning that to make smart habitat investments in this very complex and dynamic system, we needed more information,” Spraycar says.

So The Nature Conservancy turned to science-driven partners, including NASA, to develop a program it calls BirdReturns. The space agency provided imagery and sensor data from its Landsat satellites, which capture images of the entire Earth every 16 days. With a resolution of 30 meters, the imagery is detailed enough to highlight how landscapes change season by season. The Conservancy then worked with its longtime collaborator Point Blue, a conservation science nonprofit, to analyze available images and determine when and where water was present—and how those locations changed—throughout the year.

TNC ecologist Greg Golet monitors participating rice fields near Colusa in California's Sacramento Valley.
BirdReturns TNC ecologist Greg Golet monitors participating rice fields near Colusa in California's Sacramento Valley. © Drew Kelly for The Nature Conservancy

The team also relied on eBird, a Cornell Lab of Ornithology and National Audubon Society program that aggregates birder data from citizen scientists who upload millions of on-the-ground observations each month, including when and where specific species were spotted. With a grant from NASA, the Cornell Lab created a computer model to analyze that data and compare bird sightings with the wetland locations from the NASA imagery. The resulting model predicts where birds flock at different times of year.

“TNC’s innovative BirdReturns program shows the power of combining NASA satellite imagery with models and in situ bird location data,” says Woody Turner, program scientist for biological diversity and program manager for ecological forecasting for NASA’s Science Mission Directorate.

But identifying ideal locations for bird habitat was only the first step. To provide those habitats, The Nature Conservancy had to strike a deal with local landowners. The program, known as BirdReturns, pays the region’s rice farmers to create pop-up habitat for a few key weeks each year. The Conservancy asks farmers to flood these fields and manage the water depths precisely for several weeks, providing wetland rest areas for birds making their transcontinental trek.

The Conservancy's innovative BirdReturns program shows the power of combining NASA satellite imagery with models and in situ bird location data.

NASA's Science Mission Directorate

“The vast majority of habitat that’s available to birds is found on privately owned farmland,” Spraycar says. “That’s what led The Nature Conservancy to work directly with farmers to co-create these habitats alongside their other crops.”

This data-driven approach is working, with BirdReturns fields housing 10 times more shorebirds than fields outside the pilot program in the first season. But these results wouldn’t have been possible without the commitment of local landowners, says Eric Hallstein, Ph.D., chief economist for The Nature Conservancy of California.

“We had preexisting relationships in the Central Valley through our two decades of engagement there,” he says. “So we had some credibility and then built up even more trust with farmers by designing the program with their input—and ultimately paying them to create habitat.”

Farmer Doug Thomas holds rice at a storage facility near Olivehurst, California.
Taking Flight Farmer Doug Thomas holds rice at a storage facility near Olivehurst, California. © Drew Kelly

Taking Flight

The Nature Conservancy recruits local farmers to the cause with a deal that benefits their business and the birds.

The farms of California’s Central Valley feed the nation. The region’s harvest is worth an estimated $17 billion per year—and accounts for 25 percent of America’s food supply.

But intensive agriculture in the region has put pressure on local ecosystems. Wetlands have been drained to make room for row crops, leaving migrating birds few places to stop and refuel. But the sprawling irrigation infrastructure that delivers water to fields also offers a unique conservation opportunity.

“While we have lost habitat as a result of conversion to farms, we’ve also gained the ability to manage water,” says Paul Spraycar, senior project director for The Nature Conservancy’s California water program.

This puts farmers in a prime position to help provide wetland habitat precisely when and where birds need it. By flooding fields not in use, farmers can offer food and shelter for birds as they journey to their breeding ground and back again. The idea was inspired by conservation-minded farmers, a powerful sign the concept could have industry appeal.

“We flood our fields every year for the wintering waterfowl,” says Nicole Montna Van Vleck, owner of Montna Farms.  “It’s not only the way we make our living, but it’s also how we try to convey to our children our livelihood and what we value dearly.”

It was one of these ideas that seemed really insane at first. We wondered, ‘Can you actually rent wetlands? If we design a reverse auction, will these farmers actually show up?’

Chief Economist, The Nature Conservancy

But to bring it to scale, The Nature Conservancy needed an economic model that would encourage local growers to get on board.

The resulting program, BirdReturns, positions wetland habitat as a secondary crop farmers can add to their annual rotation. Using a reverse auction model, the Conservancy asks farmers to set a price to flood their fields and then selects the lowest bidders who meet its requirements.

“From a farmer’s perspective, their job is to figure out how much it costs them to create those habitat conditions, and then we get to choose the folks that can do that most efficiently,” says Eric Hallstein, Ph.D., chief economist for The Nature Conservancy of California.

When The Nature Conservancy introduced the program in 2013, the team wasn’t sure how many farmers would want to participate. There are always risks associated with a new enterprise—and growers rely on these fields for their livelihood.

“It was one of these ideas that seemed really insane at first,” Dr. Hallstein recalls. “We wondered, ‘Can you actually rent wetlands? If we design a reverse auction, will these farmers actually show up?’”

The answer was a resounding yes. Nearly 20,000 acres were offered up by dozens of farmers during the first auction. The Nature Conservancy ultimately enrolled 40 farms in the pilot program, which included 10,000 acres. These 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.

“It wildly exceeded our expectations,” Dr. Hallstein says. “And it’s just been growing since then.”

It’s a solution that meets the needs of migratory birds while also benefiting the farmers of the Central Valley.

Water Program Senior Project Director, The Nature Conservancy

Spraycar attributes the program’s appeal, in part, to providing a successful proof of concept—farmers witnessed firsthand the benefits for birds and how water could be used efficiently. And once they saw that BirdReturns fields were still productive in subsequent seasons—and that some were even easier to plant after being churned by thousands of tiny feet—farmers grew more confident in the program. As a result, BirdReturns has provided upward of 40,000 acres of habitat on more than 100 farms over the past three years. And the program has been adapted to work on fields where corn, wheat and other annual crops are planted, as well.

“As farmers have experienced the program, they’ve become more comfortable in creating habitat alongside their other crops,” Spraycar says. “It’s a solution that meets the needs of migratory birds while also benefiting the farmers of the Central Valley.”

And The Nature Conservancy is continuing to scale up the BirdReturns program, with a goal of increasing the number of shorebirds that stop in the Central Valley to 400,000. Dr. Hallstein says he believes the program can provide as much as 600,000 acres of pop-up wetlands in the next 10 years. The program could also come with added benefits, such as recharging the groundwater in certain areas for dry season storage.

“It’s an example of a conservation solution that is at the scale of the problem,” he says. “We’re complementing our traditional set of tools with another tool that really lets us find economically efficient ways of working with growers and also achieve our conservation end.”

Aerial view of flooded rice fields in California's Sacramento Valley.
Taking Flight Aerial view of flooded rice fields in California's Sacramento Valley. © Drew Kelly

Flock Together

The BirdReturns program’s success in California could ripple across other ecosystems.

When the skies darken with thick clouds of birds, it’s a sign that change is in the air. Whether it’s the onset of winter or the arrival of spring, the avian creatures are harbingers of what’s to come. 

So it’s fitting that birds are the first species to benefit from The Nature Conservancy’s pop-up habitats. While traditional conservation work has revolved around purchasing land and protecting habitat in perpetuity, the BirdReturns program creates a more flexible—and cost-effective—approach to providing habitat in a complex, crowded world.

Flocks of Dunlin in rice fields in Colusa, California.
Flock Together Flocks of Dunlin in rice fields in Colusa, California. © Drew Kelly

The Nature Conservancy converted 40,000 acres of farmland into pop-up habitats during the program’s first three years. The Conservancy estimates that permanently protecting that amount of land would cost close to $200 million. In contrast, pop-up habitats cost a fraction of that amount.

“We’re working to see just how much more economically efficient it is to rent habitat as a complement to permanently protecting habitat,” says Eric Hallstein, Ph.D., chief economist for The Nature Conservancy of California. “If we can make that kind of change, much like a nimble startup disrupting a traditional business space, we could effectively disrupt the conservation space.”

Technology and big data have the potential to allow us to be more dynamic and precise in how we manage natural resources and how we invest in conservation in nearly every ecosystem of the world.

Water Program Senior Project Director, The Nature Conservancy

There are trade-offs, of course. Prices for the short-term rentals could go up over time, for example. But pop-up habitats let conservationists react quickly in a rapidly changing environment—and the approach can be adapted to respond to other dynamic conditions, such as drought or El Niño, as well, says Paul Spraycar, senior project director for The Nature Conservancy’s California water program.

“Technology and big data have the potential to allow us to be more dynamic and precise in how we manage natural resources and how we invest in conservation in nearly every ecosystem of the world.”

Plus, the Conservancy can create large swaths of temporary habitat in the span of a few months, rather than a few decades, Spraycar says.

“The 50,000-acre Cosumnes River nature preserve in the Central Valley is the gold standard of enduring conservation work—but protecting that area was a painstaking and expensive effort that took 25 years,” he says. “We need agile tools that can complement these long-term investments. By involving farmers, BirdReturns was able to rapidly deploy 40,000 acres of temporary habitat in three years.”

The Nature Conservancy is currently focused on ramping up the program to provide habitat for migrating birds along other parts of the Pacific Flyway, all the way through Argentina and Chile.

Flocks of Dunlin in rice fields in Colusa, California.
Flock Together Flocks of Dunlin in rice fields in Colusa, California. © David Ledig

“There are some pretty exciting things that we’re working on with our Southern Andes colleagues to try and enhance wetlands at the times of year when birds need it in the Southern Hemisphere, and some of these are the same birds we see in California,” says Mark Reynolds, lead scientist for The Nature Conservancy’s migratory bird program.

Pop-up habitats could transform conservation work in global ecosystems around the world, from ranches in the western U.S. to fisheries on the other side of the globe.

For example, Reynolds’ team has been talking with partners along the Central Flyway, which stretches from the Rocky Mountains to the Gulf Coast and into South America. The agriculture infrastructure of the central U.S. offers a comparable opportunity to rent out farmland for temporary habitat. This new approach will help conservationists meet the interdependent needs of both people and nature.

“Let’s face it. We’ve already protected a lot of the pristine habitat that exists in the world. The vast majority of the remaining biodiversity that we’re trying to protect is in these working landscapes,” Dr. Hallstein says. “We need to have new tools and new ways to work in those landscapes—or we just won’t be able to have the impact we seek.”

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