Giant tortoises from the Pacific and Indian islands may be a lot cleverer than humans have previously given them credit, according to the results of a new study.
Despite a slow and lumbering reputation in the animal kingdom, tortoises from the Galapagos and Seychelle islands demonstrate remarkable memory skills over time.
Observations of the creatures show they are not only capable of being taught new tasks, but can remember their training nearly a decade later.
Tortoises were taught to bite a coloured stick to receive food, and recall the skill after nearly nine years
Around nine years ago, scientists from the Okinawa Institute of Science and Technology in Japan taught a group of captive tortoises in Vienna and Zurich zoos to bite the end of a particular coloured stick in return for food.
At the time, the tortoises were trained to bite the correct stick to receive the food when they were presented with two different coloured options.
After nearly a decade, the team returned to the enclosure that housed three of the tortoises and found that they were able to recall their skill from a decade prior.
The animals were shown to perform tasks better when surrounded by their fellow creates than when taught individually
‘Until recently, reptiles were often regarded as reflex machines, incapable of more complex behaviours, reduced to a footnote in the evolution of learning and intelligence,’ the researchers wrote in their study, which was published in the journal Animal Cognition.
The creatures were also found to learn faster when trained in a group rather than individually, even though each tortoise was assigned its own colour for the learning task.
Galapagos tortoises can live for over 100 years, making it one of the longest-living vertebrates.
Tortoises were kept alive on board the second voyage of the HMS Beagle in 1835, as an easy to store source of food
Early visitors to the Galapagos, including Charles Darwin in the early 19th century, used tortoises as a source of food during the arduous journey across the Pacific Ocean.
The HMS Beagle took more than 30 live tortoises as an easy to store and long-lasting source of food for the voyage to Polynesia.
Darwin wrote in his diary: ‘Young Tortoises make capital soup – otherwise the meat is but, to my taste, indifferent food.’
Conversely, William Dampier, a 17th-century British pirate, said they were ‘extraordinary large and fat, and so sweet, that no pullet eats more pleasantly’.
This new study represent a first step towards a wider appreciation of the cognitive abilities of the giant tortoise and less for their meat.