Aldabra Giant Tortoise
Geochelone gigantea
Description: Reaching up to 4 ft and over 700 lbs in size. Their shells range between light to dark brown with a visible neck plate that is not often found in other species of giant tortoises. Their necks are long and leathery to help adapt them to heat.
Range: Seychelles (Aldabra Island)
Habitat: Atoll islands-mangrove swamps, grasslands, and coastal dunes
Diet: Largely herbivores, but may occasionally eat carrion or eggs if vegetable matter is not available.
Weight: Males- 560 lbs; Females- 350 lbs
Body Length: Second largest species of tortoise. Females can get up to 3 feet long, Males can be 4 feet long.
Lifespan: Up to 100+ years
Status: Vulnerable
Predators: Giant Crab, Rats, Dogs, and Cats all prey on young tortoises, as well as compete for food.
Threats: Habitat loss due to development, the introduction of nonnative predators (dogs, cats, rats) and livestock that compete for food (goats), and climate change, which leads to heightened sea levels and severe droughts.
Relatives: They are a part of the Aldabrachelys genus, which is the taxonomic home of three giant tortoise species, two extinct species, and the extant Aldabra species.
Breeding: Breeding season is from February to May. In courting, the male batters his shell against a female a dozen or more times and makes a deep, trumpeting call. The female buries 9 to 25 tennis-ball-sized eggs which incubate from 110 to 250 days. Reach sexual maturity between 20 to 30 years.
Quick Facts:
The GSC is home to two male Aldabra tortoises, Traveler and Jack. They may look a little different but that is because they have different shell morphotypes. This means that these two types of shells are adapted to a specific habitat. Aldabra tortoises with domed shells like Traveler are found in humid, cooler, and higher elevation habitats while saddlebacks like Jack are found in drier areas at a lower elevation.
There are 3 extant subspecies of the Aldabra Tortoise: Aldabra giant tortoise (ours), Arnold’s giant tortoise, and the Seychelles giant tortoise. Daudin’s giant tortoise was the fourth subspecies but has been declared extinct.
There are estimated to be over 150,000-200,000 individuals scattered about the Seychelles islands. It is believed that the oldest living giant tortoise is Jonathon, a 190-year-old Seychelle Giant Tortoise who was hatched around 1832 and resides on the Island of St. Helena in the British Overseas Territory.
These tortoises can drink water through their nose, an adaptation that is useful in a mangrove environment.
Despite their weight, these tortoises are able to stay afloat in water thanks to hollow honeycomb structures within their shell. In December of 2004, an Aldabra that had been washed away from the Seychelles made the 460-mile journey to the East African Shoreline (Tanzania).
Aldabra tortoises are a keystone species that shape their habitat through seed dispersal.
The closest relatives of the Aldabra tortoise are the tortoises of Madagascar. Scientists at the Galapagos Conservancy speculate that the ancestors of giant tortoises accidentally reached isolated islands by riding on rafts of plant matter.
Conservation: Different species of giant tortoises were once found on a variety of equatorial islands. Unfortunately, over-collection for food by humans and the introduction of invasive species such as rats (which raid nests) and goats (which compete for food) drove all but 10 subspecies of Galapagos tortoises and 3 subspecies of Aldabra tortoises to extinction. It is important that these island ecosystems are carefully preserved as many are home to animals found nowhere else on Earth. Furthermore, Aldabra tortoises are helping to restore island ecosystems by being introduced to islands that have lost their native giant tortoise species.
GSC Residents:
Name: Traveler
Date of Birth: ~December 2000 to December 2001
Sex: Male
Origin: Donated from private owner October 13, 2005
Favorite Foods: Strawberries, tomatoes, bananas, watermelon
Favorite Enrichment: shell scrubs
Trained Behaviors: Target, scale, blood draw
From the Keeper: He has a dome shell. This keeps Traveler from having the ability to reach up high like Jack can.
Name: Jack
Date of Birth: ~December 1989 to December 1990
Sex: Male
Origin: Donated from private owner August 17, 2005
Favorite Foods: Tomatoes, strawberries, bananas, watermelon
Favorite Enrichment: Shell scrubs
Trained Behaviors: Target, scale, blood draw, station, color discrimination
From the Keeper: He has a saddleback shell, which allows him to reach up farther for leaves and food. They can feel through the shells which are made up of keratin and bone. He is often mistaken for a rock or a statue for how still he stands at times.
Facts about GSC Residents:
Daily Schedule
Fed main diet 3x a week, Monday, Wednesday, and Saturday. Fed browse every day. More active during the warmer weather. Will sleep, and browse throughout the day.
Training Behaviors
Due to the tortoises' immense size, we utilize several training behaviors to minimize stress on the animals and keepers. Our tortoises are target-trained, allowing us to direct them where we need them to go. Similarly, we are working with the tortoises on the Scale behavior, so that they will voluntarily walk up onto our scale for weighing. They are also working on foot/neck/poke behaviors. The foot behavior allows us to pick up their feet to see if they have any problems. The neck/poke behavior is for when we start drawing blood from their neck for health and wellness checks.
Health History
Sometimes get runny eyes due to dust, so we spray the ground with the hose to reduce dust.
Favorite Story
Jack is very sociable and loves to be scratched and rubbed. When we walk away, he will follow us wanting more
Updated 125d ago
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