What's happened
Survey shows Aldabra Atoll hosts about 183,000 adult and sub-adult Aldabra giant tortoises, the largest count yet. Conservationists warn climate shifts and invasive species remain threats, but eradication efforts could boost growth further. The findings come from five years of counting (2018–2022) by SIF and University of Exeter and published in Ecology and Evolution.
What's behind the headline?
Brief
- The latest count places the Aldabra giant tortoise population near 183,000, with education and monitoring programmes underpinning this “baseline” for future tracking.
- The study stresses that this is not an endpoint; continued vigilance is needed as climate pressures intensify and invasive mammals remain a threat.
What this means
- Longer droughts and sea-level rise could shrink shade and food, stressing tortoise populations in vulnerable habitats.
- Eradication of feral cats and black rats could remove persistent barriers to growth and resilience.
Why now
- The update consolidates a long-running monitoring effort amid broader climate concerns and biodiversity preservation goals in the Indian Ocean region.
How we got here
Three decades of conservation work helped restore Aldabra Atoll to a nature reserve first designated in 1981 and a UNESCO site in 1982. The new estimate updates the widely cited late-1990s figure of 100,000 tortoises after counts and modelling from 2018–2022. Ongoing threats include climate change, drought, and invasive mammals that prey on eggs and hatchlings.
Our analysis
According to The New York Post and The Guardian, the update synthesises five years of tortoise counts (2018–2022) analyzed by SIF and the University of Exeter and published in Ecology and Evolution. The Guardian highlights the same figures with minor wording variations; both emphasize the conservation context and future threats. The Japan Times adds context on a related individual tortoise but does not affect the population estimate.
Go deeper
- What does this mean for Aldabra’s role in conservation?
- What actions are most likely to improve resilience against climate change?
- When will the next population update be published?
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