Giant tortoises
The giant tortoise Geochelone gigantea is without question the star animal of the living laboratory that is Aldabra. Natural populations of giant land tortoises were widespread across the scattered isles of the western Indian Ocean until recent centuries when human exploration and settlement forever reshaped the natural environment. There were once numerous different species of which today only the Aldabran giant tortoise survives. Tortoises were readily plundered as a bountiful food source and populations were soon wiped out across most of the western Indian Ocean. Aldabra, as a harsh and immense semi-arid raised atoll, deterred a significant human presence and better resisted devastation of its tortoise population. Nevertheless, by the late 19th century tortoises were a rare sight on Aldabra and the efforts of prominent naturalists such as Charles Darwin were brought to bear in the strong push for their urgent protection.
The tortoises on Picard are concentrated around the area of Settlement Beach on the ocean side of Picard, the southern portion of which is occupied by the Aldabra Research Station. It is here that the most hospitable environment on the atoll is found and along with it the largest tortoises. The tortoises enjoy a morning activity period between dawn and 1000hrs with a peak at 0900hrs which is followed by a midday siesta and shade period centred around noon that runs from 1000hrs to 1400hrs. This gives way to a late afternoon period of rising activity that runs from 1400hrs until dusk.
