Melbourne Zoo’s six little giants have a ‘weigh’ to go

13 May 2022

Melbourne Zoo’s littlest giants are taking big steps to help zookeepers monitor their surprisingly speedy development.

The six young Aldabra giant tortoises, who arrived at Melbourne Zoo from Mauritius last year, have learned to climb aboard a customised weigh station, with the help of a musical instrument.

Melbourne Zoo ectotherm keeper Raelene Hobbs said the scales and a measuring tape are a workday essential.

“We keep track of their weight fluctuations and the size of their carapace – the hard upper shell – to ensure we are providing the right nutritional support in order to meet their development milestones,” said Ms Hobbs. “We want to make sure those shells continue to grow nice and healthily.

“Since arriving from Mauritius, the tortoises have put on between 20 and 30 kilograms. It’s only a matter of time before they grow much heavier.”

Giant tortoises experience a steep growth period before reaching a developmental plateau around 40 years old, by which time they will have reached weights of up to 100 kilograms for females and more than 200 kilograms for males.

The important training also empowers the tortoises to maintain choice and control over their own healthcare, while keeping the process enjoyable for all.

“We started training the tortoises to recall to the weigh station as soon as they arrived to limit handling and set them up for the best long-term animal welfare,” said Ms Hobbs. “We use a bell to signify the direction we’d like the tortoises to move towards and reinforce their successes with a delicious food reward.”

The six sub-adult giant tortoises are located in Melbourne Zoo’s Growing Wild precinct where visitors may be able to view a weigh-in training sessions.

Aldabra Giant Tortoises are one of only a few surviving species of Giant Tortoise left in the wild and have been estimated to live up to 200 years. The species is classified as Vulnerable in the wild by the International Union for Conservation of Nature after suffering the effects of poaching and habitat destruction.