About the Aldabra Tortoise
The Aldabra tortoise (Aldabrachelys gigantea) is one of the world's largest land tortoises, native to the Aldabra Atoll in the Indian Ocean (Republic of Seychelles). Males can reach a weight of up to 250–300 kg and a length of 130–150 cm, with documented cases of individuals living over 150 years.
Once classified in the same genus as the Galápagos tortoise (Chelonoidis niger), they are synonymous with giant tortoises, but are now recognized as a separate genus and species.
Wild individuals are listed under CITES Appendix II (Washington Convention Appendix II), requiring export/import permits for international trade. While keeping and selling them within Japan is not illegal, verifying the legal origin of specimens is essential (illegally imported wild-caught individuals are subject to confiscation and penalty).
Enclosure Design
Aldabra tortoises require enormous space as they grow, making long-term planning the highest priority.
Growth Stage Guidelines
| Stage | Shell Length | Body Weight | Recommended Indoor Space |
|---|
| Hatchling (just hatched) | 6–8 cm | 60–90 g | Storage container 60×60 cm or larger |
| Juvenile (1–3 years) | 15–30 cm | 1–5 kg | 90×180 cm or larger |
| Young adult (5–10 years) | 40–70 cm | 20–80 kg | 3×4 m or larger (outdoor housing recommended) |
| Adult (10+ years) | 80 cm+ | 100 kg+ | Minimum 6×6 m, ideally 20 m² or larger |
Outdoor housing is the best approach. As they reach adulthood, securing indoor space becomes impractical. Outdoor enclosures should be located in warm regions (maintaining 10°C or above year-round) and must have concrete walls or buried metal fencing (50 cm or deeper) to prevent escape.
Shelter Design
Aldabra tortoises require shade (shelter) during rest periods.
- Shelter size: Floor area at least 3 times the shell length
- Entrance: Height and width of shell length + 20 cm
- Heating: Cold climates require a hibernation shelter equipped with insulation and heating lamps
Temperature and Humidity Management
Optimal Temperature
| Category | Temperature |
|---|
| Activity temperature | 25–32°C |
| Basking spot | 35–40°C |
| Nighttime minimum | 18°C (juveniles maintained above 22°C) |
Winter heating is the greatest challenge. As tropical/subtropical species, Aldabra tortoises cannot maintain their body temperature during Japanese winters (below 10°C). Hibernation shelters must use ceramic heaters, panel heaters, or radiant floor systems to maintain temperatures above 20°C.
Humidity
The wild Aldabra Atoll is a relatively dry environment (annual rainfall 700–1000 mm). In captivity, maintain humidity around 50–70% to prevent shell and skin problems (shell softening, bacterial infections) from excessive moisture. Keeping juveniles at slightly higher humidity (60–80%) during early stages can reduce dehydration risk.
Feeding Management (Herbivorous)
Aldabra tortoises are completely herbivorous, feeding mainly on grasses, leaves, stems, fruits, and dead wood in the wild.
Primary Diet Composition
| Food type | Proportion | Examples |
|---|
| Grasses and cereals | 50–60% | Timothy hay, orchard grass, weeds (fleabane, dandelion, etc.) |
| Leafy vegetables and plants | 25–30% | Bok choy, Chinese cabbage, kale, arugula, mulberry leaves |
| Vegetables | 5–10% | Pumpkin, beans, carrots (small amounts) |
| Fruits | 5% or less (occasionally) | Apples, bananas, strawberries (monitor sugar content) |
Foods to avoid:
- Large amounts of cruciferous vegetables (cabbage, broccoli) → goitrogens (thyroid-inhibiting substances)
- Spinach (high oxalic acid → calcium absorption inhibition)
- Animal protein → kidney and gout risk
- Avocado, onion, garlic → toxicity
Feeding Frequency and Quantity
- Hatchlings to juveniles: Daily (frequent small meals)
- Young adults to adults: Daily or 5–6 times per week
- Daily amount for adults: 3–5% of body weight (e.g., 1.5–2.5 kg/day for a 50 kg individual)
Calcium Supplementation
Essential for skeletal and shell development.
- Dust vegetables with calcium powder (carbonate-based)
- Keep cuttlebone available at all times (for self-regulated gnawing)
- Promote vitamin D3 synthesis through UVB lighting or outdoor sunbathing
Growth Management and Shell Assessment
Normal Growth Guidelines
Growth rate after hatching varies significantly depending on husbandry conditions. With proper feeding and temperature management, the following are general guidelines:
| Age | Shell length | Body weight |
|---|
| Hatching | 6–8 cm | 60–90 g |
| 1 year | 12–18 cm | 300–700 g |
| 3 years | 25–35 cm | 3–8 kg |
| 5 years | 35–50 cm | 10–30 kg |
Shell Condition Assessment
Pyramiding (shell protrusions)
Results from improper diet, humidity, and excessive protein during growth. Once pyramided, the shell cannot return to normal.
Prevention includes:
- High-fiber, low-protein diet
- Proper humidity (avoiding excessive dryness)
- Regular soaking (warm water baths 1–2 times per week)
Soft shell (Metabolic Bone Disease: MBD)
Caused by calcium deficiency, insufficient UVB, and excess phosphorus. Immediate intervention is needed if a juvenile's shell is soft or deformed.
Daily Care and Health Management
Soaking
Soak 2–3 times per week in warm water (27–30°C) to a depth equal to shell length for 30 minutes.
- Hydration (reptiles absorb water through skin)
- Promotes elimination
- Moisturizes shell and skin
Regular Measurements and Records
Keeping regular growth records (shell length, weight, photos) is fundamental to health management. Sudden weight loss or growth stagnation indicates potential illness.
Veterinary Care
Reptile veterinarians experienced with Aldabra tortoises are limited. Establish a relationship with a veterinarian before acquisition and conduct annual health checks (weight, blood tests, fecal exams).
Legal Regulations and Acquisition Caution
Aldabra tortoises are listed under CITES Appendix II, requiring documentation for international trade. Legal sources within Japan include:
- Imported individuals with CITES documents: Verify that import and export permits are complete
- Domestically bred individuals (CBF0–F3): Available from specialized breeders
- Legitimate importers and specialty shops: Request documentation disclosure
Purchasing individuals with unknown origins or missing documentation carries risk of later confiscation. Always verify documentation before purchase.
Summary
Aldabra tortoises can live over 150 years—a lifespan exceeding a human lifetime. Before acquisition, carefully consider where the individual will live throughout its life and who will care for it.
With proper environmental conditions, nutrition, and medical care, Aldabra tortoises reward their keepers with serene behavior and exceptional longevity. Consider living with this magnificent creature only if you are committed to a lifelong partnership.
