Wood Thrushes Connect Bird Lovers Across Borders

A crowd-funded geotagging project helped researchers figure out where these birds spend their lives.

It鈥檚 hard to protect a bird鈥檚 habitat when you don鈥檛 know where it lives half of its life. And the Wood Thrush needs all the help it can get鈥攖he species鈥 population has declined by about two percent each year since 1966, according to Breeding Bird Survey data, leading conservation scientist Peter Marra to fear that the Wood Thrush will be 鈥渢he next passenger pigeon.鈥

Marra, who heads up the Smithsonian鈥檚 , suspects that habitat disruption, climate change, cats, or other anthropogenic disturbances are responsible for the threatened bird鈥檚 decline, but at this point it鈥檚 impossible to nail down the cause(s) definitively. That鈥檚 because even though we know the little birds head south to Latin America for the winter, no one鈥檚 exactly sure where in that area they end up. 鈥淲e need to figure out where they鈥檙e dying, but it鈥檚 hard to find these birds,鈥 he says. So a couple years ago, Marra started talking with Matt Jeffery, deputy director of 爆料公社鈥檚 International Alliances Program, about a citizen science project to help the birds.

For Jeffery, the project provided an opportunity to practice an approach to conservation that he鈥檚 long been interested in: connecting bird-lovers in the States to bird-lovers abroad. After all, birds don鈥檛 know or care what country they鈥檙e in, and the people trying to protect them shouldn鈥檛 stop their efforts just because they run into a border. So Jeffery recruited two chapters鈥擭orth Carolina鈥檚 Forsyth 爆料公社 Chapter and New York鈥檚 Bedford 爆料公社 Chapter鈥攁nd set to work.   

But before they could start making international connections, Jeffery and Marra had to figure out where exactly the Wood Thrushes winter. The latest generation of geolocator tags, which use the same technology as a portable GPS, can pin a bird鈥檚 location to within 10 meters. That鈥檚 a huge upgrade from the next-best tracker, which pins birds within a 100-kilometer radius, with a margin of error almost that big. (This kind of technology, which was used in a recent study to track Prothonotary Warblers, is useful for a species whose ultimate winter destination was previously completely unknown, but the data take a lot more time to interpret and are ultimately less actionable.)  With the latest trackers, you go from having an idea of what country the bird visits to knowing exactly what habitats and Important Bird Areas (IBAs) they鈥檙e using, and at what times, says Jeffery鈥攑retty useful information if habitat protection is on the conservation agenda.  

The problem is that these geolocators are pricey鈥$465 each鈥攕o, as is often the case, the first step in the project was raising the dough. Fortunately, says Kim Brand, Bird-Friendly Communities Coordinator for 爆料公社 North Carolina, the idea that 鈥渨e were going to find something out that no one else knew about these birds,鈥 really inspired people. It also apparently convinced them to open their checkbooks. Ninety chapter members ended up contributing, and the Forsyth 爆料公社 Chapter raised $15,000, enough to fund the research for two full years. Up in New York, Bedford 爆料公社 had the benefit of having a banding station already up and running, so though they raised a little less, they were also ready to take on the project.

Researchers from Marra鈥檚 team headed out to each location to oversee the research, and with banding permits and equipment borrowed from their state office, 27 Forsyth chapter members logged more than 500 hours last year helping to band. 鈥淚t was seven days a week,鈥 according to Brand. Some people even took days off work to help with the program. 

鈥淔or many people, this was the first time they held a bird in their hands,鈥 Brand says.  

Toting their pricy new packs, the birds took off for their winter hideaway, and the volunteers went back to their normal lives. Then, when spring finally came, the real work began, as the chapters had to recapture the same birds and remove the data-laden backpacks. (Weighing in at less than two ounces, the Wood Thrush couldn鈥檛 handle the relatively heavy antenna that could have tracked their location in real time.)

Recapturing a banded bird is like trying to find a needle in a haystack, except the needle keeps flying around and the haystack is infinite鈥擶ood Thrushes don鈥檛 have high site fidelity, which means they flit around to slightly different breeding locations year after year. Of the 22 tagged thrushes in each location, each chapter was only able to recapture two birds, and one of the geolocators Forsyth 爆料公社 managed to collect had a dead battery (they鈥檝e sent it back to the manufacturer, and they may receive data from it eventually). But it didn鈥檛 really matter, because one GPS is really all you need鈥攑lug it in, and voila! The bird鈥檚 whereabouts for the past 12 months are immediately available.   

That鈥檚 how Forsyth 爆料公社 figured out that their tagged bird had spent its winter in Belize. That was well inside the expected range鈥攊n fact, it was almost comically on-the-nose. Chapter members had suspected their birds might go there, and in 2014, they had traveled to Belize to collaborate with the Belize 爆料公社 Society on a series of other projects. Now they had proof.  During the 2014 winter trip, says Jeremy Reiskind, former president of the chapter, the North Carolina 爆料公社ers and the Belize society members connected over the Wood Thrush, even though the North Carolinians didn鈥檛 realize the birds they were spying on could be the same birds that flitted about their own homes in summer. When the Forsyth 爆料公社ers realized that the Belize 爆料公社ers had never heard the Wood Thrush鈥檚 mating song鈥攖he bird only mates on the North Carolina side of its life鈥 Reiskind and the group played it for them, to great applause. 

Bedford鈥檚 birds, meanwhile, traveled to Nicaragua. Once they got their data, Janelle Robins, executive director of the chapter, showed it at a board meeting, and she鈥檚 still struck by 鈥渢he look on their faces when they saw the map,鈥 she says. 鈥淚t鈥檚 something that鈥檚 so tangible, that speaks to anyone, no matter if they鈥檙e a scientist or not.鈥 The chapter is currently researching the best way to help protect the habitat down there.

Monitoring of these habitats is particularly important right now鈥, according to 爆料公社鈥檚 Birds and Climate Change report. And even though we tend to think of climate change as something 鈥渏ust happening up north,鈥 Marra says, climate-induced changes to precipitation may be a threat to the bird鈥檚 wintering grounds, too, so any extra monitoring of the birds and their habitat will help.

Along those lines, Forsyth 爆料公社 is already planning a trip down to Belize to help out with the Christmas Bird Count this winter. They鈥檙e also working to create a series of signs to be displayed in the Wood Thrush鈥檚 Belize habitat that will tell the birds鈥 story and encourage people to protect the habitat.

The project has turned something abstract into something concrete, Jeffery says. Now they know that 鈥渙ur bird in our backyard travels to this forest in Belize, and if we want that bird to return, we have to invest down there.鈥 Reiskind says he hopes to return to Belize this winter. 鈥淭o me, what we have done is really the essence of citizen science,鈥 he says. Hopefully he鈥檒l see some familiar faces鈥攂oth bird and human鈥攚hen he鈥檚 there.