180,000 giant tortoises roaming freely on Seychelles Islands: researches say that it is the highest figure ever recorded for the species and wonderful news

 

iant tortoise population thriving as survey discovers 180,000 on one island.

A population of Aldabra giant tortoises lives on an island in Seychelles called Aldabra Atoll.

The most recent survey, led by Seychelles Islands Foundation (SIF) and the University of Exeter, revealed there were approximately 180,000 tortoises living on the island. This is the highest figure ever recorded for the species and far exceeds the human population of Seychelles.

The new figure was obtained by a team who analysed five years of tortoise counts between 2018 and 2022. It is the first update since a widely cited figure of 100,000 tortoises from the late 1990s.

Aldabra Atoll is one of only two places in the world where giant tortoises are found in the wild, with a much smaller population living in the Galápagos.

Dr Frauke Fleischer-Dogley, the CEO of SIF, said: “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.”

There are more giant tortoises on Aldabra Atoll than humans. Photograph: Avalon.red/Alamy

The study, published in the scientific journal Ecology and Evolution, found that the population was relatively stable for this period, with a best estimate of almost 183,000 adult and sub-adult tortoises.

In the 19th century, exploitation of the animals meant there were fewer than 1,000 Aldabra tortoises left on the island, but a recovery programme led to it becoming a strict nature reserve in 1981 and a Unesco site in 1982.

Researchers are now saying it is one of the greatest conservation success stories of the Indian Ocean, with the new study confirming it. “Aldabra’s giant tortoise monitoring programme is one of the longest running in the region, but the atoll’s dense vegetation makes counting tortoises genuinely difficult in places,” said Dr Nancy Bunbury, one of the study’s co-authors.

“By modelling what we didn’t see, as well as what we did, we’ve produced the most reliable baseline yet for this iconic Seychelles species, establishing a benchmark we can use to track the population for decades to come.”

Despite the good news, the study’s authors say that vigilance is essential. Aldabra’s climate is changing, with longer and more frequent droughts predicted to reduce the shade and food available to tortoises, while rising sea levels threaten low-lying parts of the atoll.