Giant Tortoise Distribution and Abundance in the Seychelles Islands: Past, Present, and Future

Giant tortoises (Aldabrachelys or Dipsochelys) in the Seychelles Islands are critically threatened by climate change, with projections indicating severe population declines due to sea-level rise and coastal erosion over the next century. The study reveals that only 9 granitic islands currently support wild tortoise populations, totaling around 500–550 adults, while coralline islands, particularly Aldabra Atoll, host over 100,000 individuals—nearly all of them. The research provides the first census of the Frégate Island population and assesses the historical distribution and status of wild tortoises across Seychelles, identifying Ile aux Cerfs as a potential mixed indigenous-imported population. To mitigate projected losses, the study recommends expanding reintroduction programs to high granitic islands, aiming to restore ecosystem function and offset declines. The findings underscore the urgent need for conservation action to prevent further population loss and align with the IUCN Red List's Vulnerable status designation.

Gerlach, J., Rocamora, G., Gane, J., Jolliffe, K., & Vanherck, L. (2013). Giant Tortoise Distribution and Abundance in the Seychelles Islands: Past, Present, and Future. Chelonian Conservation and Biology, 12(1), 70–83. https://doi.org/10.2744/ccb-0902.1