Buffy-headed marmoset (Callithrix flaviceps) Photo By Peter Schoen – Flickr, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=23826246
Dear Readers, there has been a lot of bad and depressing news around lately, so it felt well past time to have a good news story. And here it is! One of the big problems in the Amazon basin is that roads have been built through rainforest habitats. This fragmentation can bring its own problems: seeds that are dispersed by animals, such as many nuts and seeds, don’t travel from one side of the road to the other, and animals that can’t fly are trapped in their forest ‘silos’ and can’t interbreed. But one of the most visible and distressing effects of the roads is that many animals are killed while crossing: nearly nine million mammals are killed every year in Brazil.
Enter the charity Project Reconecta. Their founder, Brazilian biologist Fernanda Alba, has been pioneering the use of low-cost, easy-to-maintain road bridges in the forest canopy. Each bridge has a camera at each end, so that the animals using the bridges can be monitored.
Eight bridges were put in place in Alta Foresta, a small town in the Mato Grosso in Brazil, in 2024. In the eighteen months following their implementation, over 15,000 crossings were recorded, and not a single road kill.
Some species take to them straight away:
Black-faced Black Spider Monkey (Ateles chamek) Photo from https://wildexpedition.com/animals/black-faced-black-spider-monkey/ )
Purus Red Howler Monkey (Alouatta puruensis) Photo By D. Gordon E. Robertson – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=17566490
Schneider’s Marmoset (Photo By Diego Silva – Costa-Araújo, R., Silva-Jr., J.S., Boubli, J.P. et al. An integrative analysis uncovers a new, pseudo-cryptic species of Amazonian marmoset (Primates: Callitrichidae: Mico) from the arc of deforestation. Sci Rep 11, 15665 (2021). https://doi.org/10.1038/s41598-021-93943-w, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=108190797)
Alta Foresta Titi Monkey (Plectourocebus grovesii) Photo By Reuber Brandão – https://www.inaturalist.org/photos/466559914, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=194054982
The Alta Foresta Titi monkey in the last photo was only discovered by Western science in 2019, and is critically endangered, so it was a real joy to see them using the bridges.
Back in 2021, Project Reconecta put 21 bridges into the area between the Brazilian states of Amazonas and Roriama, with the help of the indigenous Waimiri-Atroari people, who advised on the best places to put the bridges. This enabled the project team to note which animals used which bridges: the best used were the longest ones, possibly because the primates could jump across any shorter junctions. Some animals took a long time to feel happy about using the bridges: the Tufted Capuchins (Sapajus apella) took up to seven months before they felt confident about crossing, showing that the benefit of the bridges may reveal itself gradually over time.
Tufted Capuchin (Photo By Basile Morin – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=74555820)
It wasn’t just primates who used the bridges either: sloths, opossums and mouse opossums have also been seen using them.
Project Reconecta has big plans, and has received a number of awards for its innovative bridge designs: these are now the recommended standard for highway crossings, and Alba is working on projects in the Pantanal (where the ‘highway of death, the BR-262, kills 2,000 animals a year) and Suriname, as well as other regions in the Brazilian Amazon. The success of these projects is largely down to the involvement of everyone locally: as Alba says:
“When everyone is involved, everyone values the initiative and works harder to make it succeed.”
Let’s hope that this initiative continues to help bring animal communities together, and reduces the number of deaths of animals on the road.