Mario Herz Fig. 26. One
Mario Herz Fig. 26. One of many terraria for raising Seychelles Giant Tortoises; the terrarium has to “keep pace” with the growth of the animals. 2 m². For the last years, the tortoises have been spending their time in their new outdoor pen from June through September, depending on the weather (night temperatures not below 15 °C). This run first had a floor space of approximately 12 m² and included a hotbed (1 m²) made from 16-mm hollow-chamber sheet polycarbonate that served as a shelter. Once they had grown too large for it once more, they were granted access to the entire garden as their “outdoor terrarium” and built a protected quarter for the cold time of the year in the shape of a heated house with a floor space of 12 m². This house is also open to them in summer so that they can retreat into it on cold and rainy summer days. Once it starts raining, the tortoises will immediately leave the shelter house and cruise through the outdoor pen. I will then have a close eye on the weather conditions and bring the animals back inside if there is a risk of them catching cold. The Leopard Tortoises (Stigmochelys pardalis) from East Africa in my care show a very similar behaviour. I have not noted any irregularities in the growth of the shell in the specimens in my care under the described husbandry conditions. Much rather does their growth resemble that of the giant tortoises that used to be kept at the NTPS nursery station on the Seychelles. Ebersbach (2001) already pointed out the scarcity of available information on the growth of Seychelles Giant Tortoises. I have therefore tabulated the data on the growth of Aldabrachelys gigantea gathered by myself and other keepers: Origin Age (in months) Weight (in g) Carapace length (in cm) Hirakawa Zoo 7.5 240–550 12.0–13.0 Sydney Zoo 17 483–897 no data Sources Terahara & Moriyama (1998) Peters & Finnie (1979) Stanford Zoo 21 432–900 13.0–16.8 Stearns (1988) Tab. 1. Growth data of Aldabrachelys gigantea, modified from Ebersbach (2001). 16 RADIATA 22 (4), 2013
Aldabra Giant Tortoise, Aldabrachelys gigantea gigantea Age (in years) Average weight (in g; n = 2) Average carapace length (in cm; n = 2) 1 150 9.5 2 1,900 no data 3 4,950 no data 4 9,500 33.5 5 12,000 40.0 6 15,000 46.0 7 19,000 48.0 Age (in years) Weight (in g) Carapace length (in cm) 0 53 6.99 1 260 10.0 2 620 14.0 3 1,210 17.0 Age (in years) Weight (in g) Carapace length (in cm) 1 186 no data 2 1,000 no data 3 2,500 no data 4 4,600 no data 5 7,400 no data Tabs. 2–4. Growth data of four privately kept Aldabrachelys gigantea, including the two specimens in my care. Hatchlings in the care of Gerlach (2004a) increased their weight at hatching by 5,000 % within two years, from 40 to 2,000 g. In the two specimens in my care, a growth rate of 3,300 % within two years was recorded, and it amounted to 1,170 % with a fellow keeper. Pawlowski (2009) specified a length of 50 cm for juveniles of six years of age raised under near-natural conditions; moreover, a weight of 20 kg was recorded on reaching an age of 5.5 years for tortoises raised at the NPTS-Station (Pawlowski & Krämer 2010). Ebersbach (2001) provided further data (based on unpublished data by Schramm 1992) for juveniles raised on the island of Curieuse (Seychelles): > 1 year: 8.6–7.9 cm > 2 years: 17.3–21.21 cm > 3 years: 26.0–35.2 cm > 4 years: 34.8–38.2 cm > 5 years: 37.5 cm Aside from monetary implications for food, housing and providing the necessary illumination (energy consumption), the captive husbandry of giant tortoises also entails increased physical labour for removing the substantial amounts of faeces the tortoises leave behind, leftover food, and exchanging the bedding substrate. Picking a giant tortoise up will only be possible without major bodily strain during the first few years of its life and thereafter only with assistance. My experience therefore RADIATA 22 (4), 2013 17
