Giant tortoises prove they have turtle recall
Early visitors to the Galapagos were amused, but unimpressed, by the giant tortoises. They considered the lumbering beasts to be ‘‘living rocks’’ that roamed aimlessly and pointlessly – and whose main redeeming quality was their tastiness when fried.
Now a study has suggested a lot more was going on in the minds of these sluggish animals, who can not only be trained to perform tasks but also remember their training unprompted almost a decade later.
Ten years ago scientists from the Okinawa Institute of Science and Technology taught a group of captive tortoises to bite on the end of a stick in return for food. They showed the reptiles were able to choose the right stick when another stick was also presented, and also when the only difference between the sticks was the colour.
The researchers did this, they said, in part because of the unfair reputation the animals have for stupidity. ‘‘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,’’ they wrote in the journal Animal Cognition.
It was only when the scientists came back to test them again that they realised just how wrong this idea was. The team went to the enclosure at Vienna zoo, that housed three of the same animals tested previously, and found that they remembered the rules of the game they were taught years earlier.
‘‘Remarkably, animals that were tested nine years after the initial training still retained [their abilities],’’ they wrote. The tortoises appeared to be the elephants of the reptile world, with a memory that matched their extremely long lifespan.
The findings would certainly have been a surprise to the first westerners to see the animals. Much of their popularity among sailors stemmed from the fact they could be stored alive in the hold of ships for months at a time, keeping their meat fresh.
However, there were hints even then in the more observant visitors that there was something more special about the animals. Darwin noted they could cover many miles in a day, navigating the island from sleeping ground to feeding ground to watering hole.
The researchers said it was time to formalise the observations made by Darwin and rehabilitate the maligned giant tortoise. ‘‘Our study is a first step towards a wider appreciation of the cognitive abilities of these unique animals,’’ they said. – The Times