Aldabrachelys

Aldabrachelys is a genus of large, terrestrial tortoises in the family Testudinidae. The most widely known member is the Aldabra giant tortoise, Aldabrachelys gigantea, native to the Aldabra Atoll in the Seychelles. The genus is primarily represented today by this living species, with other members known from fossil records and the genus having a history of inclusion in other tortoise genera in earlier classifications.

Taxonomy has shifted over time. The Aldabra giant tortoise has been placed in Geochelone and Dipsochelys in various systems, but many modern authorities recognize Aldabrachelys gigantea in the genus Aldabrachelys. Some classifications also assign fossil taxa to Aldabrachelys, reflecting a broader historical use of the name for island giant tortoises.

Description and ecology. Aldabrachelys gigantea is a very large tortoise with a high-domed carapace and stout, pillar-like legs. Adults can exceed a meter in length and weigh well over 100 kilograms. They are herbivorous, feeding on grasses, leaves, fruits, and other plant matter. They occupy shorelines and inland habitats on Aldabra and display slow, long-lived life history traits typical of giant tortoises.

Life history. Reproduction involves females laying several eggs per clutch in sandy substrates. Incubation periods vary with temperature and conditions, and hatchlings emerge after many months. Longevity is among the hallmarks of the species, with lifespans commonly approaching a century or more in the wild.

Conservation. The Aldabra giant tortoise is listed as Vulnerable by the IUCN, with major protections afforded on Aldabra Atoll within a protected area and UNESCO World Heritage Site. Conservation programs focus on habitat protection, monitoring populations, and minimizing threats from introduced predators and habitat change.