Read on for the story of Dr Tamar Gutnick, an incredible biologist. All words in bold can be found in the glossary at the end of the story. Questions and resources can also be found after the glossary. Happy reading!
Meet Tamar. She’s a research scientist from Israel.
Tamar loves tortoises. They might not be as big or colourful as other animals, but to her, they are fascinating.
Tamar likes to watch the tortoises at her local reptile centre.
All the tortoises that Tamar has met look slightly different – some are bigger, some smaller. Some have unusual patterns on their shells, or a unique mark on their skin. These traits allow Tamar to see who is who.
The more she watched the tortoises, the more Tamar noticed that each one behaved differently, too. Some were always first to the food bowl, even if it meant pushing others out of the way, while some hung back. Some liked to explore all the corners of their enclosure, but others didn’t seem interested in leaving the comfort of their hutch.
Scientists like Tamar call these differences personalities. Just like you and me have our own personalities, so do tortoises and other animals! They can be bold, shy, active, or lazy – just like humans can!
Because tortoises are slow-moving, scientists had always assumed that they were slow-thinking, too. They thought the animals were stupid, and even described them as being like living rocks! Tamar thought differently. She was sure that tortoises were cleverer than scientists believed.
To be able to prove that tortoises are clever, Tamar needed the help of some real-life ones which she could train and observe. Sadly, she could not reach any of the habitats of tortoises in the wild. The tortoises there would be difficult to find, and getting to them would take a lot of time and money. So, to help her with her research, Tamar turned to tortoises in zoos.
Tamar travelled to Austria to visit Timmy the tortoise and his friends, at Vienna Zoo. Timmy is a Galapagos Tortoise – the largest species of tortoise on the planet. As well as getting very large, Galapagos tortoises can be incredibly old, with some living for over 100 years in the wild. Imagine how much they must see in that 100 years!
Tamar wanted to test whether Timmy had a good memory. Tortoises of his species were able to live for so long – she wanted to know whether they might be able to remember any useful information that could help them to survive for all that time.
Other scientists had found that reptiles, including tortoises, were able to solve mazes and remember the location of food.
Can you help this tortoise find their way to some tasty treats?
Tamar wanted to see if Timmy could remember how to complete tasks, in the same way that a mammal like a dog can learn and remember how to sit when they’re told to. So, armed with Timmy’s favourite snacks (dandelion and beetroot!) to use as rewards, Tamar set to work with his training.
The first task was simple: Tamar wanted to teach Timmy to bite a green ball on the end of a stick. She began by touching Timmy’s nose with the ball, to draw his attention to it. After the ball touched his nose, she gave him a treat.
After a while, Timmy began to bite the ball without Tamar having to touch it to his nose. From then on, she only gave treats when he bit the ball by himself, without her prompting him. Soon, he learned to bite the ball when Tamar simply held the stick out in front of him. He had mastered the first task!
Next, Tamar moved onto something a bit more difficult – teaching Timmy to move towards the ball when it was held up to 2 metres away. To us humans, 2 metres might not sound like a long way to travel, but for tortoises it’s quite a distance! Tortoises aren’t built for speed – their hard shells protect them from predators, so they don’t need to run away, and they mostly eat plants, which they never need to chase down.
Though it took Timmy a while to learn to move towards the target (mostly because tortoises only move about 8cm every 10 minutes), he eventually mastered this task too.
Now for the hardest test of all!
Remember when Tamar taught Timmy to bite a green ball, back in the first task? She wanted to test whether Timmy had learned the colour of the ball that he should bite. So, she offered him both the green ball and a ‘distractor’ ball at the same time. The ‘distractor’ ball was exactly the same as the green one, except that it was red rather than green.
Timmy’s task was to remember which ball was the right one to bite. If Timmy bit the green ball, Tamar would know that he had remembered what colour he should bite. If not, then she would know that he had learned just to bite any ball, not his particular one.
During the task, Timmy had to walk towards the balls and then pick the right one – it combined learning to bite, learning to go to, and the new element of remembering the right colour. Tamar was careful to look away from both of the balls while Timmy was doing the task, to make sure she didn’t give him any clues about which one to bite.
Timmy remembered the correct ball! The training was a success! Tamar treated Timmy to a feast of his favourite snacks, to reward him for his hard work.
Over the next few weeks, Tamar repeated the task several times, often switching which side the green ball was on, and every time she did, Timmy made the right choice.
Tamar then did the training and test with 14 more tortoises – Timmy’s friends!
It was important that she repeated the training with lots of other tortoises, to make sure that her results were similar for them all. She wanted to show that they all had good memories, not just Timmy!
She did the training in the same way every time (though the colour of the ball changed for each tortoise). This made sure that the experiment was a fair test.
The other tortoises managed to memorise the tasks correctly too. This meant that Tamar knew that her results weren’t just due to chance, or to Timmy having an unusually excellent memory. She was right – tortoises have good memories!
Even more interestingly, Tamar found that tortoises learnt better when they were in a group. This might be because the tortoises can learn faster if they’ve watched another tortoise complete the task, compared with if they’ve never seen it happen. Scientists didn’t know that tortoises were able to learn from each other in this way!
To test whether Timmy’s memory of the tasks lasted for a long time, Tamar came back to visit him three months later.
Timmy remembered that when the ball was presented to him, he should bite it, and that, when the ball was held out some distance away, he should travel towards it. Though he didn’t remember that he had been trained to bite a green ball specifically, he relearned which colour ball to bite quickly – much faster than he had the first time Tamar had taught him.
Tamar was so proud of Timmy – his memory was remarkable!
Even more impressively, when Tamar returned again a whole nine years later, Timmy still remembered that biting or going towards a target would get him a tasty reward. That means that Timmy’s memory had lasted for longer than some of you have been alive!
Through teaching her tasks, Tamar discovered that tortoises could remember things for a long time, and that they learnt better in groups than alone. These are signs that tortoises are clever. Learning from watching others also shows that tortoises can do a special kind of learning, called social learning.
These were two important discoveries, which she could not have found out without Timmy and the other zoo tortoises’ help. Together, Timmy and Tamar proved that tortoises were far from stupid. The truth is, that though they may be slow-moving, tortoises are likely to be a lot cleverer than anyone knew.
Learning from tortoises like Timmy may have important consequences for his relatives in the wild. Knowing how tortoises’ brains work, through experiments like Tamar’s, will help scientists look after them in the future.
There’s still lots to learn – Tamar will be requiring Timmy’s help again soon, as she continues to find out about how reptiles think.
Maybe, in the future, you could help her too!
Thank you for reading!
This story was written as part of a Masters in Science Communication project, investigating whether storytelling is an effective way to teach children about science and scientists. As a result, I would really appreciate some feedback, which you can give by answering a short survey. The survey takes less than 5 minutes to complete, and I will use the results to develop even better science stories in the future. To help, just click on the button below.
Tamar’s research paper: Gutnick, T., Weissenbacher, A., Kuba, M. (2020). The underestimated giants: operant conditioning, visual discrimination and long-term memory in giant tortoises. Animal Cognition. 23: 159-167.
More information about Tamar and Timmy:
More information about Fair Tests:
More information about Galapagos Tortoises (Timmy’s species!):
The research was produced not just by Tamar Gutnick, but also by the other members of her research team: Anton Weissenbacher and Michael Kuba. They too deserve credit for this discovery – good science is often best done as a team.
This story would not be nearly so good without its illustrations by the wonderful Daisy Harrison, and the advice and support of Dr. Nicola Hemmings. Thank you!