Aldabra Giant Tortoises Outnumber Seychelles' People: Survey Estimates About 180,000

A survey published in the journal Ecology and Evolution in October 2026 estimates that about 180,000 to 183,000 Aldabra giant tortoises live on Aldabra Atoll in the Seychelles. That is more than the country's human population, which the sources put at roughly 122,000 to 135,000 depending on the date and estimate used. The finding matters for exams because it combines a species-recovery story with facts on protected areas, UNESCO status and threats to island ecosystems.

What happened and when

The study is complete and published. The sources do not give an exact publication day for the paper. GKToday dates it to October 2026. CNN's syndicated report, carried by ABC17 News, was published on 8 October 2026, and GKToday's article is dated 13 October 2026. These are news-report dates, not the dates of the fieldwork.

The population figure rests on tortoise counts collected over five years, from 2018 to 2022. The survey was led by the Seychelles Islands Foundation (SIF) and the University of Exeter in the UK. The full paper is linked in the CNN report: https://onlinelibrary.wiley.com/doi/10.1002/ece3.74282.

Key facts at a glance

Why the tortoises "outnumber" people

The comparison

The comparison sets the tortoise population of one atoll against the human population of the whole country. The sources give different human figures:

• CNN: around 122,000.
• GKToday: about 123,000 at the end of 2025, and 134,959 estimated for mid-2026.

The sources do not explain why these figures differ, and this page does not pick one. Every figure quoted is below 180,000, so the headline holds under each of them.

An estimate, not a headcount

The 180,000 to 183,000 range is a modelled estimate, not a count of every animal. GKToday says the researchers used advanced statistical modelling to account for tortoises hidden by dense vegetation. CNN quotes co-author Nancy Bunbury as saying the atoll's dense vegetation makes counting genuinely difficult in places. She described the result as the most reliable baseline to date, one that can serve as a benchmark for tracking the population over decades.

How new is the figure?

GKToday calls this the first rigorous whole-atoll estimate since the late 1990s. CNN calls it the first update since the widely cited estimate of 100,000 from that period. CNN also describes it as the highest figure ever recorded for the species. That superlative comes from one source and is attributed here, not independently verified.

Conservation background

Heavy exploitation in the 19th century cut the atoll's tortoise population to fewer than 1,000, bringing the species close to extinction. Aldabra Atoll was declared a strict nature reserve in 1981 and became a UNESCO World Heritage Site in 1982. CNN links a recovery programme to securing the reserve status. The atoll is managed by the Seychelles Islands Foundation.

According to CNN, Aldabra is one of only two places where giant tortoises live in the wild. The other is Ecuador's Galápagos Islands, which has a much smaller population. SIF chief executive Frauke Fleischer-Dogley called the result proof of what long-term conservation commitment can achieve.

Threats that remain

• Climate change: longer and more frequent droughts could reduce shade and food for the tortoises.
• Sea-level rise: it threatens the atoll's low-lying habitat.
• Invasive species: GKToday names feral cats and black rats as risks to the habitat and to tortoise survival.

The study's authors say continued vigilance and long-term monitoring remain important despite the encouraging estimate.

Exam-relevant points

• Remember the two protection years in order: 1981 for strict nature reserve status, 1982 for World Heritage inscription.
• Know the organisations: Seychelles Islands Foundation (SIF) and the University of Exeter.
• Note the wording: the figure is an estimate drawn from 2018–2022 data, not a single-day census.
• The sources do not say whether this topic has appeared in or will appear in any exam.

FAQ

Where do Aldabra giant tortoises live?

According to the sources, they live in the wild on Aldabra Atoll in the Seychelles, with a much smaller population in the Galápagos Islands.

Is the survey figure an exact count?

No. It is a modelled estimate that accounts for tortoises hidden by vegetation.

Practice MCQs

Question 1

Which two organisations led the Aldabra giant tortoise survey?

1. Seychelles Islands Foundation and University of Exeter
2. UNESCO and the Galápagos National Park
3. Seychelles Islands Foundation and Guinness World Records
4. University of Exeter and the Government of Ecuador

Answer: Seychelles Islands Foundation and University of Exeter — both sources say the survey was led by these two bodies.

Question 2

The survey's estimate of Aldabra giant tortoises, as reported by GKToday, is:

1. About 100,000
2. Fewer than 1,000
3. 180,000 to 183,000
4. About 134,959

Answer: 180,000 to 183,000 — GKToday reports this range for Aldabra Atoll.

Question 3

In which period was the data used for the survey collected?

1. 1981 to 1982
2. 2018 to 2022
3. Late 1990s
4. 2025 to 2026

Answer: 2018 to 2022 — both sources say the estimate is based on five years of counts from 2018 to 2022.

Question 4

Aldabra Atoll became a strict nature reserve and a UNESCO World Heritage Site in which years, respectively?

1. 1982 and 1981
2. 1981 and 1982
3. 1981 and 2018
4. 1998 and 2022

Answer: 1981 and 1982 — the sources date the strict nature reserve to 1981 and UNESCO World Heritage status to 1982.

Question 5

Which pair of invasive species does GKToday name as risks on Aldabra?

1. Feral cats and black rats
2. Feral goats and mongooses
3. Black rats and foxes
4. Feral cats and stray dogs

Answer: Feral cats and black rats — GKToday names these as invasive species posing risks to the habitat and tortoise survival.