As many as 183,000 giant tortoises thrive in the Seychelles, a new survey has found.
The Aldabra giant tortoise (Aldabrachelys gigantea) are said to be an endangered species. A survey led by the Seychelles Islands Foundation (SIF) and the University of Exeter found that the identified population is the “highest figure ever recorded for the species.” The discovery is a huge victory for conservation efforts across the Indian Ocean.
Population rise
The current population contrasts sharply with the late 19th century, when hunting and habitat exploitation nearly drove the reptiles to extinction. It left fewer than 1,000 survivors on the isolated coral ring.
Swift intervention reversed their decline after Aldabra was designated a strict nature reserve in 1981 and a UNESCO World Heritage site in 1982. Rigorous legal protection combined with the successful eradication of invasive feral goats in 2012 ultimately paved the way for this historic recovery.
“The monitoring data in this study were collected by SIF staff living and working on the atoll, year after year. More than 180,000 giant tortoises roaming freely on our atoll is proof of what long-term commitment to conservation can achieve. This is wonderful news for Seychelles, for the world, and for everyone who has worked to protect Aldabra,” said Dr Frauke Fleischer-Dogley, CEO of SIF.
A baseline for the future
However, determining the population count was not straightforward. It required almost five years of dedicated field monitoring by SIF researchers alongside statistical experts at the University of Exeter. The actual counting process proved to be a complex challenge.
Aldabra’s landscape consists of sharp coral and thick, tangled vegetation. Tortoises routinely seek shade under dense bushes, vanish into mangroves, or shelter from the scorching equatorial sun. Previous surveys relied on raw headcounts.
As a result, older estimates, such as the long-cited 100,000 figure from the late 1990s, likely missed tens of thousands of hidden animals.