São Paulo sprawls across the coastal plateau of southeastern Brazil like several large U.S. cities mashed together. More than 20 million people live in the greater metropolitan area known as Grande São Paulo. As my plane descended toward the capital on a visit to Brazil earlier this year, the city spread out before me, perfectly lit by the morning sun. I saw a carpet of concrete skyscrapers stretching mile after mile.

It's hardly a landscape where scientists would expect to discover a new bird species. But in 2004, that's exactly what happened. Dante Buzzetti, a Brazilian ornithologist, identified a small, secretive bird in a marshy area about 30 miles from the city center. Now the race is on to protect the remaining habitat for the São Paulo Marsh Antwren, a critically endangered species that lives in the shadow of South America's largest metropolis.

São Paulo Marsh Antwren male. Scientists believe fewer than 300 individuals remain in the marshes near São Paulo, Brazil. Photo by Elvis Japão

After Buzzetti discovered the São Paulo Marsh Antwren, he and other researchers looked for the dark, long-tailed bird among many marshes east of the city. São Paulo sits on a plateau, with the mountains of Serra da Cantareira to the north and the Atlantic Ocean to the south. Eventually Buzzetti and the researchers found the species present at more than a dozen sites in the headwaters of two rivers. They estimated the total antwren population at 250 to 300 individuals.

Additional research later estimated that the species occupied a total area of just 350 acres. The bird had likely lost more than 74,000 acres of its historic habitat in the last 200 years, the research found, a result of sand mining, urban development, fish farms, drainage for agriculture and pastures, invasive plants, and flooding from dams.

It is unclear exactly how extensive the São Paulo Marsh Antwren's range used to be. But over the past century, this city of millions has grown up and now occupies part of the bird's relatively small range. The remaining areas, meanwhile, are vulnerable to development. The few birds that are left need immediate conservation action to survive.

During my visit, I planned to meet with conservationists who want to collaborate with local government officials to protect the antwren's marshy habitat. And I hoped to see this mysterious bird. For hundreds of thousands of years the stealthy antwren had lived quietly in the wetlands. Only recently did we learn of its existence — and its need for help.

Cities and Rare Birds, in Close Proximity

The International Union for the Conservation of Nature (IUCN) added the antwren to its Red List of Threatened Species in late 2016. Researchers had recommended the group consider the species to be critically endangered and noted that no protected areas existed to ensure the species' survival. The scientists urged conservation measures to save the bird and its habitat.

The idea of creating a protected area for birds in or near a city might seem unusual. Urban areas strike many people as inhospitable places for birds, harboring such threats as invasive species, dangerous glass windows, or pollution. Typically we instead imagine wilderness and remote reserves, far from people. Yet conservationists are increasingly working to conserve birds within working landscapes like cattle ranches or timber plantations.

São Paulo, Brazil, is South America's largest city. Photo by Filipe Frazao/Shutterstock

As the São Paulo Marsh Antwren shows, some of the most important areas for rare species are within or near urban areas. This may not be a coincidence. Ornithologist Jon Fjeldså has documented a positive relationship between endemic bird areas in the Andes and centers of human civilization. He hypothesizes that these same areas have been more stable in their climate over long periods of time, providing steady patterns of rainfall. This maintains habitat for endemic bird populations and allows agriculture to flourish for people. As a result, many of the high Andean forests with the most endemic birds are very close to major and ancient cities, like Cusco, Peru (population 435,000) and Cochabamba, Bolivia (population 630,000).

A Conservation Opportunity

When ABC evaluated the update to IUCN's Red List late last year, the São Paulo Marsh Antwren stood out as a conservation opportunity. So in early 2017, I called Pedro Develey, Executive Director of SAVE Brasil, one of our partner organizations.

SAVE Brasil is a leading Brazilian bird conservation group, and happens to be headquartered in São Paulo. Coincidentally, Pedro was meeting later that morning with local organizations and government officials from the municipality of Guararema who wanted to create a protected area for the antwren. Without good funding prospects, Pedro was skeptical that there was much SAVE Brasil could do to help.

I encouraged him to find out all he could of the proposal. American Bird Conservancy (ABC) would be interested in supporting the creation of a new protected area for the antwren, I told him. It would be a start to what would certainly be a broader, long-term effort required for this species to survive.

The local campaign for the antwren, I soon found out, had an important ingredient for success: strong local support for the creation of a protected area. In many efforts to establish new protected areas, garnering the support of local communities can often take time. But enthusiasm was only part of the equation. The municipality also needed funding to conduct a census of the bird's population and other baseline biological studies. The timing was urgent. With financial support from ABC board member David Davidson and his wife, Patricia, ABC soon had a contract signed with SAVE Brasil. Work would begin just two months later.

On the Trail of the Reclusive São Paulo Marsh Antwren

I took a redeye flight from Washington, D.C. to São Paulo in March. It was my first trip to this impressive country of warm and friendly people. I looked forward to meeting with some of its passionate conservationists.

The next day, Pedro and I drove out to Guararema along with Bennett Hennessey, who manages many of ABC's projects in Brazil. We crossed São Paulo's concrete expanse and a countryside denuded of most of its original forest. Along the way, after turning off the main highway, we spotted a large raptor atop a snag. We pulled over to get a better look. It was a juvenile Crowned Eagle (sometimes known as Chaco Eagle), another critically endangered species, a life bird for our group and not one any of us had expected to see. This was a good sign: The spot was close to the proposed protected area, so our work might benefit the eagle as well.

One of the marshes east of Sao Paulo where the marsh antwren is found. This marsh and the forest behind it are in the area proposed for protection. Photo by Daniel Lebbin

We stopped for a family-style lunch in Guararema, where we met the rest of our group. Among them was Ricardo Moscatelli, an environmental consultant and director of the municipality's Secretariat of Environment and Urban Planning, and Marcos Grangeiro, from the conservation organization Guaranature. All were enthusiastic about the antwren project. With maps spread out on a table, we reviewed the surrounding area — points where the antwren had been observed and lines indicating where the reserve might be. Then we piled into our cars. Our next stop: a visit to remnant marshes nestled in a matrix of vast eucalyptus plantations, the occasional cattle pasture, and small patches of original forest.

The São Paulo Marsh Antwren typically occurs in pairs or family groups of four. The birds do not fly far and spend most of their time foraging for insects. Pairs travel close together and communicate with infrequent, short, and quiet calls. Both sexes will defend their territory.

At the first marsh we visited, we saw a male skulking; at the next stop, we spotted a pair near a waterfall, popular among locals as a swimming hole. In both cases the birds traveled through dense vegetation over water, stayed deep in the cover of shadow without venturing into the open, and vocalized softly. Being so inconspicuous within a wet habitat that people might hesitate to wade into, it was not a surprise that they had remained undetected by scientists for so long.

Watching the antwrens with Ricardo, Pedro, and other local project supporters was a joyful experience. Sharing the sight of a rare bird at a local patch, as many birders know, can often make friends out of strangers. This gathering was even more special because we not only enjoyed a shared birding experience, but were allies in a pioneering conservation effort.

Lasting Links with Nature

The campaign to save the antwren's habitat may seem very local, playing out over just a few hundred acres. But there's much more at stake. As people around the world increasingly live and work in cities, we are losing our connection with nature in our daily lives. Children, especially, can suffer from an affliction known as “nature deficit disorder,” a term coined by sociologist Richard Louv in his 2005 book “Last Child in the Woods.”

Natural urban oases, therefore, are more essential than ever in improving the quality of life for city dwellers. Urban parks provide important spaces for recreation, can be crucial in ensuring clean and reliable drinking water, and can protect steep slopes from erosion and landslides.

Activities are now underway by SAVE Brasil and our other partners to preserve important habitat for the antwren and, in the process, to protect some of São Paulo's few remaining marshes for posterity. Any attempt to create a park or protected area — whether in Brazil or Baltimore — requires community support, scientific research, and formal approval from the local governing body. This effort, fortunately, already has strong support among many residents of Guararema.

A female São Paulo Marsh Antwren. The bird typically occurs in pairs or family groups of four; the birds do not fly far, and spend most of their time foraging for insects. Photo by Elvis Japão

Going forward, scientists will conduct baseline studies of the bird, other wildlife, and soil; supporters will determine the boundaries of the area they want the government to protect; and local officials must formally approve the plan. And we are hopeful that a major producer of eucalyptus pulp, Fibria, which owns a large amount of land within the antwren's habitat and has shown interest in the project, will support efforts to conserve important habitat.

The venture is off to a strong start. If we can create the first protected marshes in Guararema, we hope it will serve as a model and inspire the protection of additional marshes that are home to larger populations of the São Paulo Marsh Antwren. Eventually, it might even be possible to restore marshes to increase available habitat. But for now we must start somewhere — and the good political will in Guararema presents a promising opportunity.

In the grand sweep of natural history, the São Paulo Marsh Antwren is a relatively young species. Scientists think it diverged somewhere between 250,000 and 640,000 years ago from its sister species, the Paraná Antwren, another rare bird that occurs in marshes on the other side of the Serra do Mar mountain range. But thanks to the efforts of a few dedicated individuals in one of the world's largest cities, the story of its conservation is just beginning.

This article first appeared in the Fall 2017 issue of Bird Conservation magazine.

Daniel Lebbin is the Vice President of Threatened Species at American Bird Conservancy. He completed his Ph.D. dissertation at Cornell University in 2007 on habitat specialization of Amazonian birds.