The new Aldabra giant tortoise monitoring programme protocol finalised in August marks a milestone for Aldabra research.

The new protocol has been in development for at least a year, in collaboration with external researchers and the Zurich Aldabra Research Platform team. The tortoises will now be monitored using two new methods; distance transects and sweep surveys. The new survey methods were presented to the research team and then an infield training session was conducted.

Aldabra Atoll hosts the largest wild Aldabra giant tortoise population in the world, amounting to about 100,000. The species has been monitored by SIF every month since 1998. However a review of the data collected over the years identified some shortcomings of the previous study and recommended new methodologies to be set up. Distance transects and sweep surveys have been identified as appropriate methods to survey the large herbivores. Distance transects will allow management to accurately determine the total population of tortoises on the atoll and follow its trend. On the other hand, the sweep surveys will provide vital information on tortoise biology such as size, sex and age, with an increased understanding on other factors like their distribution, mortality and recruitment on the atoll. Other components of the sweep survey involve identifying and monitoring key tortoises nesting areas, as well as mark and recapture.

Technology use will be improved for better data collection, the distance transects will be conducted using distance pointers and the sweep surveys will be recorded directly on a hand held device called the Trimble, enabling a standardised and more efficient data collection process. The surveys will be conducted twice a year, at several locations on the atoll, encompassing different vegetation types.

The science coordinator presented these new methods to both the research and logistics staff.

Infield training was also given to the research team to ensure all the surveyors are properly trained for the new monitoring programme.

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