Radiated Tortoise

1 Overview

The radiated tortoise (Geochelone radiata), also the ‘radiated’ or ‘solar’ tortoise, is named for the radiating lines on its shell. A fairly common, moderately easy tortoise, so many keep it.

One of Madagascar’s rare tortoises (less rare than the ploughshare). Both declined from habitat loss; radiated tortoises are also eaten locally. Both are CITES Appendix I – export and import banned, so almost no wild exports except captive-bred. CONSERVATION NOTE: CITES I.

2 Appearance

Market forms named by pattern: ‘sun radiata’, ‘full-flower’, ‘firework’, ‘black’. The typical star pattern radiates from each black or dark-brown scute centre; some have brighter ground with darker rays, sometimes on the plastron too. The radiated has the clearest, most vivid pattern and is the largest star tortoise (about 40 cm or 16 in). Unlike Indian star tortoises its scutes are not domed, so the shell is smooth. Legs and feet yellow like the head; males longer-tailed with more concave plastron.

Found only in southern Madagascar (called ‘Sokakes’), in dry brush or forest. Wild: herbivorous (grass, succulents including introduced cactus); captive: many fruits and vegetables (sweet potato, carrot, apple, banana, alfalfa, melons). Reportedly prefers red food.

3 Care & Temperament

Once endangered, now conserved and captive-bred, it is beloved. The US SSP (Species Survival Plan, from 1985) manages 179 founder tortoises across 13 institutions for maximum genetic diversity – if a lineage is over-represented, that animal is loaned to display-only zoos. Captive breeding has succeeded (343 recorded captives); this shields it from extinction though it does not justify wild habitat loss.

Called ‘the rich man’s sulcata’ in Japan; Taiwan imported thousands from 2000. Early imports were hardy ‘black radiata’ (cold-tolerant, fast-growing, tend to pyramid); later ‘sun radiata’ are prettier but less disease and cold tolerant with higher mortality and slower growth.

4 Habitat & Environment

One of the easier tortoises – with sound organs, a correct setup yields growth rings within a month. Needs about 30 C and 50-60% humidity; loves water – provide a large water pan under a spot lamp for drinking, soaking and humidity.

Common ailments: colds (keep at 30 C plus vitamins, no drugs), enteritis (probiotic plus fibre; severe = amoxicillin), parasites (warm, non-refrigerated food – never feed straight from the fridge).

5 Diet & Feeding

Not hard: big appetite, fast growth, lively, needs plenty of drinking water. Notably one of the cleanest tortoises – little odour, no tail residue. Males breed only above 30 cm; males longer-tailed, females shorter with more protruding front plastron.