BirdLife: The Magazine Apr-Jun 2018 - Page 31

t’s not called the “African Galapagos” for nothing. The island of São Tomé, off the west coast of central Africa, is truly one of a kind. For a start, it has a remarkable level of endemism for such a small island: 18 of its 126 bird species are confined to that island alone. It is also unusual in that it has no recorded human-driven bird extinctions – yet. The island’s rugged landscape has protected its bird population from human influence, but this has proven a double-edged sword, making it difficult to survey the island. And it does need to be surveyed. Because, as every conservationist knows, knowledge is power. We can’t conserve a species unless we know where they live, which habitats they prefer, what’s threatening them and how many (or how few) there are. What we do know is this. Among the island’s 18 endemic bird species, ten are classed as globally threatened, with three listed as Critically Endangered on the IUCN Red List: the Newton’s Fiscal Lanius newtoni, Sao Tome Grosbeak Crithagra concolor and Dwarf Olive Ibis Bostrychia bocagei. These three species formed the focus of an intrepid survey to discover more about the secretive forests of this island. I 4 0 Photos from the expedition Photo Hugo Sampaio A selection of São Tomé’s avian life. Clockwise from top left: Golden-backed Bishop Euplectes aureus; Red-headed Lovebird Agapornis pullarius; Sao Tome Paradise-flycatcher Terpsiphone atrochalybeia; Sao Tome Prinia Prinia molleri; Newton’s Sunbird Anabathmis newtonii; Newton’s Fiscal Lanius newtoni; Sao Tome White- eye Zosterops feae (center); Giant Weaver Ploceus grandis Photos Lars Petersson 2 Prior to the survey, the Newton’s Fiscal and Sao Tome Grosbeak were assumed to have a population of fewer than 50 individuals. The Newton’s Fiscal in particular was hardly ever sighted: often, only its distant calls revealed it was still there. The Dwarf Olive Ibis fared somewhat better in terms of population size, but lost out by being the only one targeted by hunters. And hunters aren’t the only problem. Most of São Tomé’s birds live in its forests – but these are being encroached upon by human activity. Records show that the island used to be entirely covered in forest, but over half of it has been cleared, mostly for crops, such as cocoa, coffee and oil palm. Invasive species, such as feral pigs or the Quinine plant Cinchona ledgeriana, have also irrevocably changed the landscape. São Tomé Obô Natural Park, home to most of the island’s endemic species, offers protection from apr-jun 2018 • birdlife some of these threats, but not all. And so, in 2016, a team of intrepid conservationists including SPEA (BirdLife in Portugal) and the RSPB (BirdLife in the UK) set out to survey the island. It wasn’t easy. Surveyors faced a range of challenges: despite the small size of the island, torrential rain, mountainous escarpments of up to 2,000m and venomous snakes made the landscape hard to traverse. Ricardo de Lima, lead author of the study, describes the experience: “It was very intense. We had a large team on the ground, sometimes camping in the forest for over a week, carrying tents, food and equipment on our backs, and moving camp almost every night.” But it was worth it, with the results shedding a new light on these mysterious birds. The findings were revealing and unexpected, presenting both good and bad news, and showing just how much scientists hadn’t realised about the ecology of these species – and of the forests as a whole. On one hand, all three species were discovered in previously 31