Radiated Tortoise

🔤 Taxonomy

Astrochelys radiata is the currently accepted scientific name. Older literature and some trade records may still use Testudo radiata or Geochelone radiata.

Common names used in the hobby:

• Radiated tortoise

📌 Description

A large, long-lived Madagascar tortoise with exceptional legal restrictions, high space needs, strong UVB needs, and a dry-season herbivorous diet.

Adult size is usually 35-40 cm, with adult weight around 8000-16000 g and a potential lifespan of 60-100 years. Plan the adult enclosure before purchase, not after the juvenile outgrows a starter pen.

🌍 Distribution

Native to southern and south-western Madagascar, especially dry spiny forest, scrub, thorny vegetation, and open grazing edges. In captivity, focus on bright sun, dry shelters, edible grasses and browse, shaded retreats, and seasonal hydration without making the whole pen wet.

🌡 Climate across the native range

Monthly climate normals from reviewed GBIF occurrence locations:

Weather data by WorldClim v2.1 · Monthly normals queried by Herpeton Academy from raster values; relative humidity is derived from vapor pressure and mean temperature.

Location references use GBIF.org occurrence data where available; original occurrence records retain their source dataset licenses.

⚖️ Legal status

As of 2026-06-05, this article records the species as CITES Appendix I, EU Annex A, and Bern Convention not relevant. In the EU, Annex A animals can require certificates and marking even when they are captive bred. Do not rely on a seller’s verbal claim. Local ownership, registration, transport, breeding, sale, and import rules may still apply, so keep invoices, breeder details, transfer or import/export documents, and identification photos with the animal’s records.

🤌 Husbandry

Build housing around walking space, grazing, strong light, dry shelters, and security. Outdoor pens are best only where climate and theft protection are realistic; indoor housing should be room-sized, bright, and dry enough to prevent shell and respiratory problems.

A practical adult starting footprint is about 6 m², with a starting footprint around 300 x 200 cm. Larger adults, females, groups, or outdoor housing need more space and duplicate basking, feeding, and retreat options where relevant.

💡 Lighting

Use a clear 10-12 hour day-night cycle, bright visible light, and measured UVB. Plan UVB around Ferguson Zone 3 at the basking area, with shaded retreats close enough for the tortoise to leave the light.

Indoor animals need a reliable UVB lamp or regular safe outdoor sunlight. Glass and most plastics block useful UVB, so measure the real UVI at shell height.

🌡 Heating and temperature

Typical structured targets are:

• ambient air: 24-30°C
• basking surface: 32-35°C
• cool retreat: 20-24°C
• night: 18-23°C

Use thermostats, separate thermometers, and surface-temperature checks. Heat should create a usable gradient, not one uniform hot box.

💧 Humidity and water

Structured humidity target: 50-70%. Short local access around 70-80% may support hydration, skin, or nesting needs, but the whole enclosure should not become stagnant.

Fresh drinking water and short controlled soaks are useful, but cold damp sleeping areas are dangerous.

🌿 Enclosure and decoration

Use strong, opaque low fencing outdoors, locked gates, anti-digging edges, and heated indoor retreat space for cold or wet periods. Substrate should be firm and walkable: soil-based surfaces, dry shelters, edible grasses, browse plants, shaded shrubs, and clean feeding areas. Avoid slick floors and permanently wet bedding.

🥬 Feeding

Feed a high-fiber, low-sugar herbivore diet. Good staples include grasses, dandelion, plantain, sow thistle, hibiscus leaves and flowers, mulberry leaves, grape leaves, and other safe browse. Commercial tortoise pellets can be occasional support, not the foundation; fruit should be rare.

🥚 Breeding

This is an oviparous species. Typical clutch size is about 3-12 eggs, with incubation around 28-31°C for about 120-180 days.

Seasonal cues should use rainfall, diet variety, and photoperiod while maintaining safe warmth; do not chill this species like a temperate tortoise.

🩺 Common problems

Common failures are small pens, weak UVB, rich grocery diets, damp sleeping areas, obesity, poor calcium balance, and undocumented animals.

Quarantine new animals, record weights, and use an experienced reptile veterinarian for nasal discharge, wheezing, swollen eyes, injuries, persistent refusal to eat, shell softness, diarrhea, or sustained weight loss.

📌 Conclusion

The radiated tortoise suits only keepers who can combine legal paperwork, large secure housing, strong sunlight or measured UVB, and decades of conservative care.

📚 Sources and further reading

Key sources checked for this revision:

• CITES Appendices
• Checklist of CITES Species
• European Commission wildlife trade overview
• Radiated and Spider Tortoise Husbandry Manual
• GBIF Backbone Taxonomy
• WorldClim v2.1