Research projects: Giant tortoises

The giant tortoise Schurli, who reached an age of over 120 years, was the oldest resident of Schönbrunn Zoo. Together with Mädi and Menschik, two other members of the same species, he is included in a major study conducted by the Hebrew University (Jerusalem, Israel).

The results of the study were published under the title “The underestimated giants” in the journal “Animal Cognition“.


In the framework of this project, the biologists Michael Kuba and Tamar Gutnick determined the degree to which giant tortoises can learn and are able to retain what they learned.


Giant tortoises are known primarily for their slow movements and longevity. Little, however, is known about the cognitive abilities of reptiles in general. This provided a unique window of opportunity for research.


The study was based on a learning experiment. The researchers successfully taught the turtles to associate a visual signal with food: In a first step the animals were trained to recognize that they would receive a carrot if they bit into a ball of a certain color. In a second step the animals successfully selected the correctly colored ball when presented with two color alternatives.

Both after three months as well as after nine years, the animals were still able to repeat the task. This demonstrated that turtles are not only capable of learning but that they have a good long-term memory.


Gutnick T, Weissenbacher A, Kuba MJ. The underestimated giants: operant conditioning, visual discrimination and long-term memory in giant tortoises. Anim Cogn. 2020 Jan;23(1):159-167. doi: 10.1007/s10071-019-01326-6. Epub 2019 Nov 13. PMID: 31720927.