Population study on Astrochelys radiata (SHAW, 1802) in the Tsimanampetsotsa National Park, southwest Madagascar

During three months of studying a population of Astrochelys radiata in the Tsimanampetsotsa National Park, data for 132 tortoises were recorded. On two parallel transects, carapace length and weight of each animal were carried out and the exact location of each animal discovered during surveys recorded. Population densities of 32 to 47 animals per km² were estimated. A four-day survey to the eastern boundary of the park was carried out to gain data from a less human influenced region. Even though the study took place during the dry season the tortoises were found in abundance. During this study a great number of large and therefore old tortoises were found on the transects. In contrast, the comparison study near the eastern edge of the Park exclusively yielded large tortoises. This fact could not be suitably analysed within this study due to time constraints but should be taken into consideration in future studies. Transect T2 showed greater population densities of Astrochelys radiata compared to transect T1. Even though low numbers of tortoises were recorded during the transect study a viable population of A. radiata at Tsimanampetsotsa can be inferred.