Are tortoises capable of play? Exploring reptile cognition on Curious Cases

Overview

In Curious Cases, hosts Hannah Fry and Dara Ó Briain explore whether tortoises and other reptiles engage in play, showing they can recognise people, remember information for long periods, and exhibit mood states. The episode features experts Anna Wilkinson, Una Averson, and Gordon Burghardt, discussing how play is identified, the role of captivity, and welfare implications for pet reptiles.

“Tortoises can recognise different people using faces and voices,” - Anna Wilkinson

Introduction and Context

The episode opens with a lighthearted look at a missing tortoise, Shelby, and uses this anecdote to springboard into serious questions about reptile cognition. The dialogue situates tortoises as remarkable, long-lived pets whose mental life has been underestimated. The hosts frame the discussion around play, memory, mood, and social recognition in reptiles, emphasizing the welfare implications of keeping tortoises as companions.

"Tortoises can recognise different people, using faces and voices, and they remember information for months or even years," - Anna Wilkinson

Evidence of Cognition in Tortoises

Anna Wilkinson explains that tortoises are not the simple, slow creatures many assume. They have tetrachromatic colour vision, can remember colours and outcomes for long periods, and show individual preferences for different people. Experimental methods include showing tortoises photos of familiar and unfamiliar people and testing responses to voices, demonstrating recognition and memory that outlasts many human project timelines. The discussion places these findings in the broader context of reptile cognition, noting that memory capacities in tortoises extend well beyond the typical expectations of a non-mammalian species.

"Color vision is wiser than ours—tetrachromacy in tortoises means they see millions of colors, including ultraviolet," - Anna Wilkinson

Play in Reptiles: Evidence and Nuance

The experts outline a growing body of evidence that reptiles engage in play, particularly in captive or enriched environments where needs are met. Examples include Nile soft-shelled turtles displaying object-based play and ball-pythons fetching balls, suggesting spontaneous, non-functional exploration. The conversation stresses the difficulty of defining play across diverse reptiles and the importance of repeatability and context to distinguish play from other behaviours such as mating or foraging.

"There is evidence of play in reptiles, including crocodilians sliding down water features, but we need repeatability to confirm," - Gordon Burghardt

Welfare Implications and Future Directions

Discussions extend to how humans should think about reptile welfare in homes and zoos. The experts argue for recognizing cognitive and emotional capacities in reptiles, adjusting care practices to provide enrichment, and considering how captivity may reveal play that wild settings obscure. The episode ends with reflections on the tortoise Shelby’s long life and the idea that curiosity and play can shape how we treat reptiles as companions, as well as how researchers design environments that support their welfare and natural behaviours.

"If you meet their basic needs, reptiles show remarkable abilities and can be more interactive than often expected," - Anna Wilkinson