Turtles, mangroves and chimpanzees in Guinea-Bissau

NASA’s Earth Observatory counts 88 islands and islets in the Bijagós Archipelago. Twice each day, the tidal cycle exposes mudflats and sandflats at low tide; rising water covers them again hours later. UNESCO’s 2025 inscription covers 394,067 ha and notes that five of the seven sea-turtle species frequent the archipelago. The 2013–2017 figures average 27,251 nests per year; a separate entry records that Poilão alone topped 62,000 in 2020. Catry and colleagues’ 2000 survey estimated 7,400 clutches on Poilão; their 2002 abstract also records the island’s sacred status for Bijagós people and the marine park designation in August 2000. A 2024 study links Poilão’s high nest density to later turtles destroying earlier clutches. It estimated mean hatching success at 67.9 ± 36.7% for 631 Poilão nests (2015–2022); it left out 222 of 853 monitored nests whose location was lost, which the authors say may overestimate hatching success. Its separate 2019 estimate for 21 nests on nearby Meio was 11.9 ± 23.6%.[1][2][3][4]

Ramsar’s formal name for the site is Parc Naturel des Mangroves du Fleuve Cacheu (PNTC), along the tidal Cacheu River in Guinea-Bissau’s Cacheu region. Its 2015 site record gives an area of 88,615 ha and a designation date of 22 May 2015. The intertidal park contains mangroves, other forest, palm groves and savannah. Ramsar lists six mangrove species and more than 248 birds, including greater and lesser flamingos and pink-backed pelicans; its mammals include hippopotamuses and West African manatees. The site description notes that people living inside the park have long relied on farming and artisanal fishing.[5]

The study took place in Cantanhez National Park, in Guinea-Bissau’s Tombali region in the southwest. The 2021 study describes a landscape of settlements and cropland interwoven with sub-humid and secondary forest, mangroves and savannah; it cites an estimate of 10–12 chimpanzee communities across the park. Researchers examined four neighbouring, unhabituated communities in central Cantanhez. Across 23 months (February 2017–December 2018), the team used camera traps, walked 187 survey routes spanning just over 1,000 km and collected abandoned tools. Three of the four groups yielded honey-dipping sticks. The researchers catalogued 204 examples across 70 tool-use sites. Tool forms differed with honey type and community. The authors propose that some sets may contain tools used one after another for distinct tasks. These findings concern the four sampled communities, not all chimpanzees in the park.[6]