- A six-year-old project to return giant tortoises to the wild in Madagascar could result in thousands of the 350kg megaherbivores re-populating the island for the first time in 600 years.
- The first group of Aldabra giant tortoises (Aldabrachelys gigantea) were brought in from the Seychelles in 2018, and have been reproducing on their own since.
What is the Aldabra giant tortoise and why is it important?
- The Aldabra giant is the second-largest species of land tortoise in the world, after the Galapagos giant tortoise (Chelonoidis nigra).
- This tortoise evolved from ancestors of Aldabrachelys abrupta, one of two giant tortoises that inhabited Madagascar for 15 million years.
- The reintroduction of the Aldabra giant is the first time giant tortoises have been released in Madagascar since the 1500s.
How difficult was it to reintroduce this tortoise to Madagascar?
- I am an ecologist and conservation biologist working in Madagascar and I modelled the impact the tortoise could have on vegetation.
- The first group of 12 giant tortoises, five males and seven females, arrived and were fitted with transponders before being released.
- Through natural breeding, this project aims to have 500 wild giant tortoises in Anjajavy Reserve by 2030 and about 2,000 by 2040.
Why is it important to bring the tortoise back?
- Our research predicts that reintroducing the Aldabra giant tortoise will limit such fires in the future.
- Without the tortoise helping seeds to germinate for the past 600 years, endemic trees have not reproduced as fast as they could have.
- We believe that reintroducing the tortoise will speed up the growth of forest and woodland considerably.
- But between 1700 and 1840, all Mascarene giant tortoise species were driven to extinction by humans.
Grant Joseph does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.