The Aldabra Tortoise, scientifically designated Aldabrachelys gigantea, is one of only two surviving species of giant tortoises endemic to oceanic islands, the other being the GalΓ‘pagos Tortoises. The genus name Aldabrachelys means "Aldabra turtle," directly referencing their endemic origin on Aldabra Atoll in the Seychelles, Indian Ocean. The species name gigantea means "gigantic," accurately describing their massive size. This distinctive tortoise represents one of the most spectacular examples of island gigantism, where island-dwelling species evolve larger body sizes than mainland relatives.
Common names are consistent and descriptive. "Aldabra Tortoise" or "Aldabra Giant Tortoise" clearly indicates both the species' origin (Aldabra Atoll) and most distinctive characteristic (giant size). They're occasionally called "Seychelles Giant Tortoise" referencing the island nation where Aldabra Atoll is located, though this can cause confusion with other extinct Seychelles tortoise species. Alternative names are rare, with "Aldabra" being universally recognized in both scientific and common usage.
No subspecies are currently recognized within Aldabrachelys gigantea, though historical taxonomy was more complex. All populations on Aldabra Atoll are considered a single species. Historically, numerous distinct giant tortoise species inhabited islands throughout the Indian Ocean, but most were driven extinct by human hunting and habitat destruction. Aldabra Tortoises represent survivors of this once-diverse radiation. Recent genetic studies have explored relationships between Aldabra Tortoises and extinct species from nearby islands, occasionally leading to taxonomic revisions, but for practical captive care purposes, all living Aldabra Tortoises are treated as A. gigantea.
Aldabra Tortoises were formerly classified in the genus Geochelone alongside GalΓ‘pagos Tortoises and other large tortoises. However, genetic analysis revealed that Aldabra and GalΓ‘pagos giant tortoises evolved gigantism independently on separate lineages, leading to their reclassification into separate genera reflecting evolutionary relationships rather than superficial similarities. Aldabra Tortoises (Aldabrachelys) are more closely related to some smaller Malagasy tortoises than to GalΓ‘pagos Tortoises, despite their similar appearance and ecological roles.
Understanding the conservation and ecological context of Aldabra Tortoises helps appreciate their significance beyond being impressive animals. They're the dominant herbivore on Aldabra Atoll, playing crucial roles in vegetation dynamics, seed dispersal, and ecosystem structure. The atoll's protection has prevented their extinction unlike most island giant tortoises worldwide. They represent a conservation success story, with populations now estimated at over 100,000 individuals β a remarkable number given most giant tortoises are severely endangered or extinct.
Within the family Testudinidae (tortoises), Aldabra Tortoises represent extreme specialization for large body size. Their gigantism is an evolutionary response to island life with abundant vegetation, no large predators, and inter-specific competition selecting for size. Understanding this context helps appreciate why they have such specific requirements in captivity β their biology is adapted for a very particular island ecosystem that's difficult to replicate artificially.
For captive keeping purposes, all Aldabra Tortoises available in the pet trade (a very limited number given legal restrictions and cost) are essentially identical in care requirements regardless of origin. The species is listed under CITES Appendix II, regulating international trade and requiring proper documentation. Legal captive animals are captive-bred from permitted breeding operations or legally imported with proper permits. The illegal wildlife trade has historically threatened Aldabra Tortoises despite their protected status. Prospective keepers must ensure absolutely legal acquisition with proper documentation β illegal possession of Aldabra Tortoises carries severe penalties and contributes to conservation threats.

