The Indian Ocean giant tortoise Testudo gigantea on Aldabra

摘要: The Indian Ocean giant tortoise survives on Aldabra, an atoll north-west of Madagascar. Bristol Seychelles Expedition estimated the total numbers as 33,000 during visits in 1964 and 1965. Growth movements were recorded marking experiments. growth rate with size is plotted, time scale being derived from number rings shields shell; curve compared that for captive tortoises. Variation many characters supposed taxonomic value explained influence environmental factors normal pattern, non-adaptive differences expressed adult life. present separation north south forms not supported. An explanation suggested uniformity shape among tortoises. Observations made feeding, diurnal mortality tortoises Aldabra.