Giant tortoises used to be widespread on islands around the world, however they have only survived in two places - Aldabra and Galapagos.

Mature males have an average carapace length of 120 cm and can weigh up to 250 kg. Their estimated lifespan is over 100 years, possibly up to 150 years.

The only population of dugong in the Seychelles uses Aldabra's lagoon as a breeding and nursing area, feeding on the seagrass beds.

Commonly known as sea-cows, they are very similar to manatees in appearance and behaviour, although their tails are fluked rather than paddle shaped.

Believed to be the last surviving flightless bird in the Indian Ocean, they lay their eggs on the ground and often feed by following tortoises and taking invertabrates from the disturbed litter. The Aldabra Rail was wiped out in a flood 136,000 years ago and re-emerged through "iterative evolution", which can be incredibly quick in the right conditions.

Aldabra has eleven species of land crabs, including three types of hermit crabs.

The coconut crab, the world's largest terrestrial arthropod, can span up to a metre across and weigh up to 3kg. It gets its name from its penchant for coconuts, which it cracks open with its powerful claws.

Up to 20 metres long and weighing in at 34 tonnes, the whale shark is the largest living fish on Earth, feeding on plankton, krill and small marine animals.

The best time to see them is September to December, with a peak around October.

Usually seen between July and September, the mothers use the region as a nursing area for their calves. From time to time, they have been spotted entering Aldabra's lagoon via its channels, which are 15-25m deep.

They migrate annually between here and the Southern Ocean, which they use as feeding grounds.

The archipelago is a significant breeding ground for green turtles, which lay their eggs between January and September, returning to the same sandy beaches where they were born. A small population of critically-endangered hawksbill nest from September through to March. Loggerhead turtles also like to feed in the area, although they reproduce elsewhere.

Unique to Aldabra, the males of this sparrow-like weaver are particularly majestic, with a scarlet head and yellow belly.

They can be spotted in scrub, coconut groves, mangroves and casuarina woodland. Monogamous and territorial, the male sings in his territory to defend it.

Grand Terre on Aldabra has one of only two populations in the world, the other being in the Galapagos.

The flamingos build nests in the low-lying mangroves, fashioning mud into a pillar to hold an individual egg, and like to forage for algae and shellfish in brackish waters.

The Indian Ocean's largest colony of these tropical seabirds nests amongst the mangroves of Aldabra's inland lagoon, with around 10,000 pairs and a stable or increasing population.

They forage exclusively over oceanic waters, flying in loops of 1000km or more at a slow pace to conserve energy.

There are three known species of lizard, including a skink and two gecko species.

The Abbott's Day Gecko is endemic to Aldabra, with a bright green body, blue or turquoise spots, and vibrant red or orange eyes. Feeding on insects and fruit, it typically reaches about 140mm in length.