150,000 giant tortoises

Aldabra Atoll is inhabited by a dozen researchers and about 150,000 giant tortoises that each weigh several hundred pounds and live for well over 100 years (the tortoises, that is, the researchers were all young and slim). If you’re not familiar with an atoll, it is a ring of reef and low-lying islands surrounding a central lagoon, formed after a long extinct volcano in the center eroded to nothing over millions of years.

Nearby Cosmoledo Atoll, showing the typical ring of low lying islands. Aldabra is too big to fit in one picture like this.

Giant tortoises used to live in warm areas around the globe but were hunted to extinction by humans everywhere but in the extremely isolated islands of the Galapagos and Aldabra. Even there, the tortoises were at risk after their discovery by Europeans because they can stay alive for months without food or water and were thus a useful source of fresh meat on long voyages. Aldabra is now a protected World Heritage Site and the tortoises are secure and doing well.

I’m doing well, thanks for asking.

Aldabra is governed by the Seychelles but far from the main inhabited islands that make up the rest of the country. It can only be reached by boat. Due to its remote location and permitting process required to visit it, only 20 or so tourist boats will come this year, up from zero a few years ago when the island was in a no-go area because of Somali pirates. But the staff on the island was very receptive to tourists, perhaps because the foundation that protects the island is funded in part by private donors so they like the good PR. They even had a little gift shop, where Laurel bought an official Aldabra t-shirt and coffee mug. We landed at the research station and were greeted right away by a giant tortoise. Then another, and another. We are used to long searches to get fleeting glimpses of the exciting rare wildlife of a particular location, but Aldabra is teaming with the giants. They are roaming around the cottages in the station, parked along the path into the forest, pretty much everywhere you look, chomping grass like cows.

Aldabra is also known for its sea life, being a marine protected area as well. Regrettably, the wind and waves were rough during our visit, so we were unable to snorkel. Aldabra Atoll itself is the largest of a group of four islands, collectively the Aldabra Group. We were able to snorkel at two of the other islands in the group, Assumption and Cosmoledo, but the continuing rough seas limited what we could see.

The Aldabra Group is coincidentally a hot-bed of activity for another giant shelled reptile, sea turtles. In a brief land visit to Assumption Island, we found fresh tracks from nesting sea turtles every several paces down the beach. Notice our footprints for scale next to the tracks below.

Finally, a few videos from the Aldabra Group:

  • The tortoises spend 99% of their time munching grass. Perhaps it isn’t very exciting in the usual sense but it is hypnotic and relaxing to watch these prehistoric creatures go about their business.
  • Here is a tortoise in action, racing past.
  • Cruising the lagoon of Adlabra at sunset, while the birds come home to roost.
  • We had a chance to snorkel with a couple flapping stingrays, all of us being pulled along by a strong current.

5 thoughts on “150,000 giant tortoises”

    1. They did not have any predators before humans arrived, though today human-introduced rats and cats can eat the eggs and babies. Cats have been eradicated from some of the smaller islands of the atoll and research is ongoing about how to remove the rats and remaining cats. Goats were also introduced by Europeans (who competed with the tortoises for vegetation) but the goats were recently eradicated also. All such operations are very difficult because of the rough terrain, lots of very pointy rock and sink holes. Sometimes the staff will find tortoises stuck in holes or wedged upside down in the rocks :-( They free them when possible but I bet that was a significant cause of death in the pre-human days.

      The tortoises who live around the research station are very used to humans, and one even approached us to have his neck scratched. The ones out in the bush range between indifferent and a bit annoyed, but mostly indifferent. Tourists are only allowed to visit fairly close to the station so they can’t annoy the shy tortoises much.

  1. The Giant Tortoises pictures are extraordinary – right out of Jurassic Park. Amazing to get such close access to them. Also loving all the pictures of snorkeling too (Aquawoman. ) The underwater shots are beautiful.

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