Birds In the News

Saving Colombia's Forests Is Crucial to Protect Prothonotary Warblers

A new study shows that almost the entire population winters in a region with rampant deforestation—a finding that could help target conservation.

This article first appeared on Audubon.org.

In 2016, the government of Colombia signed a peace accord with the rebel group known as FARC, bringing an end to six decades of armed conflict that reportedly claimed more than 260,000 lives. It was a historic agreement that earned a Nobel Peace Prize for Juan Manuel Santos, the country’s president at the time.

Almost immediately, though, a destructive side effect of the truce became apparent. As FARC fighters cleared out of their remote forest strongholds, miners, loggers, farmers, and others rushed in. Illegal land clearing accelerated. In the year after the peace deal, Colombia lost more than 1 million acres of tree cover, according to the World Resources Institute—a 46 percent increase from 2016.

Such rampant deforestation is bad for the global climate, bad for soil fertility, and bad for wildlife. And in particular, researchers now report, it’s bad for Prothonotary Warblers. While some migratory birds fan out across multiple areas of Central or South America in the non-breeding season, more than 90 percent of these lemon-yellow wood warblers spend their winters in Colombia, in a region with the country’s last remaining forest cover and its second-highest rate of forest loss, according to a study published Wednesday in the journal The Condor: Ornithological Applications.

That puts Prothonotaries in a precarious position, but the bright side of the study is that the findings can help governments and conservation groups target efforts to protect habitat for the bird, whose population has declined by around 40 percent since the 1960s. “There are very specific regions we can work in to get the biggest bang for our conservation buck,” says Christopher Tonra, a conservation biologist at The Ohio State University and the paper’s lead author. “Doing work in Colombia on Prothonotary Warblers—I feel very strongly that it’s going to have positive impacts across the population.”

The study arose from an Audubon-led research collaborative. In 2013, Louisiana Bird Observatory founder Jared Wolfe partnered with the Baton Rouge Audubon Society to attach geolocators to three Prothonotaries at that city’s Bluebonnet Swamp Nature Center. Geolocators are small, lightweight devices that record the time of sunrise and sunset, allowing scientists to later estimate a bird’s latitude and longitude over time. Only one of those three geolocators provided viable data in that first experiment, but it yielded such useful insights about migration that Erik Johnson, director of bird conservation at Audubon Louisiana and a friend of Wolfe’s, decided in 2014 to convene a working group to study the species across its annual life cycle.

For the new study, that group of university and government scientists, volunteers, and Audubon staff—including at Audubon South Carolina’s Beidler Forest—attached 149 geolocators to Prothonotary Warblers at sites in six states across the bird’s breeding range, which spans forested wetlands from the Southeast to the Mid-Atlantic and Midwest.

All told, 33 geolocators from recaptured warblers provided usable winter data for the study. And of those tagged birds, 30—representing each participating state—spent their winters in northern Colombia. It surprised researchers to learn that birds from all over the eastern United States cluster so closely during winter in an area about one-fifth the size of their breeding range, says Johnson, who also is a co-author of the paper. “There needs to be a lot of emphasis right now on trying to protect as much habitat as we can in that region,” he says.

Until now, conventional wisdom held that non-breeding Prothonotaries depend heavily on coastal mangrove forests, but the new findings indicate that, while they undoubtedly use mangrove habitat, inland forests provide key winter habitat. That could be good news for the birds, since mangroves are already rare, rapidly shrinking, and highly vulnerable to sea-level rise driven by climate change.

Along with new insights about the Prothonotary Warbler’s winter habitat, the results showed that the birds rely heavily on three sites during migration—Mexico’s Yucatan Peninsula, on the Honduras-Nicaragua border, and along Costa Rica’s border with Panama—where they made long stopovers. 

Magdalena River Valley, Colombia. Photo: Karol Kozlowski/Alamy.

Such information is helpful for those working to protect tropical forests, including Audubon’s International Alliances Program, which partners with local communities to develop ecotourism as an alternative to extractive industries in impoverished areas in Latin America and the Caribbean. The program and its BirdLife partner group Calidris have a focus on nurturing bird-based tourism in Colombia, home to the world’s greatest avian diversity with more than 1,900 species. Its Northern Colombia Birding Trail isn’t far from the Magdalena River Valley that the new data suggest is a winter hotspot for Prothonotaries, and program staff are working to improve management for birds and bird tourism at two nearby national parks, says Matt Jeffery, the program’s director. Audubon’s international work also includes conservation efforts along the bird’s migratory route in Belize and on the Costa Rica-Panama border.

“What we’re doing to try to combat [deforestation] is fighting economics with economics by creating jobs and local economies through bird tourism,” Jeffery says. “I fully recognize it’s not the savior, it’s not going to change everything. But it’s making the government sit up and look a little bit at alternatives to land conversion.”

Even if binocular-wielding tourists alone aren’t enough to stop the destruction of Colombia’s forests, exploring a tropical paradise with knowledgeable local guides is a pretty nice way to contribute to the conservation of Prothonotary Warblers and many more species. Birders, it can be assumed, won't need a lot of convincing to pitch in.