From fewer than 1,000 to 183,000: the tortoises that now outnumber Seychelles' people

On Aldabra Atoll, a remote ring of islands in the Seychelles, giant tortoises shuffle through the grass in numbers that would have seemed impossible 150 years ago. Hunting by sailors in the 19th century cut the population to fewer than 1,000 animals. A new peer-reviewed survey, led by the Seychelles Islands Foundation with the University of Exeter and published in Ecology and Evolution, gives the first rigorous atoll-wide count: almost 183,000 adult and subadult tortoises — more than the entire human population of the Seychelles. The researchers are careful: older counts missed animals hidden in scrub and shade, so the population has not literally doubled since the 1990s estimate of about 100,000. But it has genuinely grown, and it held steady across the 2018–2022 survey years — the payoff of protection since Aldabra became a strict nature reserve in 1981 and a UNESCO World Heritage Site in 1982.

SDG 15 · Life on land — Mechanism: institutional program