Aldabra's giant tortoises number about 180,000

Researchers put the number of Aldabra giant tortoises on Aldabra Atoll at about 180,000, the largest estimate ever recorded for the species. The University of Exeter reported on October 7, 2026, that the best estimate is almost 183,000 adults and sub-adults, and that the population looked stable from 2018 to 2022. The work, with the Seychelles Islands Foundation, is published in Ecology and Evolution.

It is the first rigorous count across the whole atoll since a late-1990s figure of about 100,000. The new total does not mean the tortoises nearly doubled. Earlier surveys missed animals in scrub and shade. The team used Bayesian hierarchical distance sampling. Hunting in the 19th century cut the population to fewer than 1,000. Aldabra became a strict nature reserve in 1981 and a UNESCO site in 1982. Goats were removed in 2012. Feral cats and black rats still eat eggs and hatchlings, and drought and rising seas remain future pressures. The densest groups are on the short tortoise turf. Aldabra and the Galápagos are the only places with wild giant tortoises. Seychelles Islands Foundation chief executive Frauke Fleischer-Dogley, Nancy Bunbury, and Exeter researcher Dave Hudson described the count as a baseline, not a reason to relax protection.