The first time Brazilian biologist Fernanda Abra saw a Groves’ titi monkey, one of the most 25 endangered primates in the world, it was positioned right next to a road.
“It was totally exposed to road mortality,” recalls Abra.
Although figures vary wildly, by some estimates, 475 million vertebrate animals are killed by vehicles every year in the South American country, which is home to the world’s fourth biggest road network, and the Amazon rainforest.
It’s a problem that Abra, who is a postdoctoral fellow at the Smithsonian’s Center for Conservation and Sustainability, Conservation Biology Institute, has been trying to solve by building bridges at the canopy level, so tree-dwelling species can safely traverse roadways.
Wildlife crossings around the world
Working with local partners including the indigenous Waimiri-Atroari people, who hold important knowledge about the wildlife in their territory in the Brazilian states of Amazonas and Roraima, Abra’s Reconecta Project has built more than 30 canopy crossings on the BR-174, a 3,300-kilometer (2,000-mile) highway slicing through the Amazon. In 2024, she was among the winners of the Whitley Fund for Nature Award, which celebrates grassroots conservationists, for her efforts.
Abra hopes the structures can help turn things around for some of Brazil’s vulnerable and endangered species, like the Groves’ titi, the Schneider’s marmoset, and the Guiana Spider Monkey.
Each bridge is fitted with cameras to monitor the animals using it, and those that approach it but turn away, so the structure can be redesigned to convince critters to cross.
“Every time I see the video of the monkey using my canopy bridge, it’s wonderful because we are avoiding the situation of road mortality,” says Abra.
Reconnecting fragments of forest that have been cut apart by human-built infrastructure can have other benefits, like giving animals access to more food resources and potential mates.
“Connecting the population, we can make it stronger and allow it to grow,” says Abra.
That could be crucial as Brazil builds more roads. In 2023, Brazil’s president Luiz Inácio Lula da Silva announced plans to spend almost $200 billion on infrastructure, including new highways.
Similar approaches are being put into use across the world. In California, an overpass is under construction above the 10-lane 101 Freeway, that will provide safe passage for animals like mountain lions, coyotes and bobcats.
Abra also has plans for growth. The Reconecta Project is now expanding in Alta Floresta, a city in the west-central state of Mato Grosso, where she’s engaging officials from various government departments and representatives from non-profits and universities, she says. The canopy bridges will be supplemented with measures like speed bumps to slow down traffic and wildlife crossing signs to alert motorists.
She hopes to eventually expand to other areas in Brazil. “What amazes me about Brazil is the richness that we have, the wonderful biodiversity we have here,” says Abra, “and I will do everything that I can as a person, as a professional, as a conservationist and researcher to protect this rich biodiversity.”