Tortoises have feelings - and they get stuck in bad moods

Red-footed tortoises may have more complex mood patterns than we thought. A new study by the University of Lincoln reveals that these reptiles can experience long-lasting emotional states.

Scientists who specialize in animal cognition now believe red-footed tortoises show mood-linked behaviors and signs of subjectivity once thought unique to birds and mammals.

The research opens a new chapter in how we understand reptile minds. It points to long-term mood states, not just momentary reactions.

If tortoises can experience optimism and pessimism, it challenges deep-rooted beliefs about reptile sentience. This could reshape how we care for them, especially in captivity.

Emotions and moods among animals

Emotions are short-term reactions tied to specific events. Moods are long-term and independent of immediate context.

Moods reflect ongoing internal states that shape how animals process the world. Evidence of mood in a species supports the idea that it has the capacity for sentience.

Affective states, which include both emotions and moods, likely evolved because they help animals avoid harm and seek valuable resources. These states also influence how animals learn and make decisions. If an animal is distressed, it may perform poorly in cognitive tasks.

When supported socially or placed in comfortable environments, its performance improves.

How tortoise moods were tested

The researchers tested 15 red-footed tortoises using a cognitive bias task. The tortoises learned to associate one location with food and another with no reward.

Then, the food bowl was placed in ambiguous positions between those two points. Tortoises that approached uncertain bowls quickly were seen as optimistic.

The team also assessed the tortoises’ behavior in response to new objects and environments. Confident tortoises moved quickly and extended their heads more. This head extension is a known indicator of emotional state in tortoises.

Importantly, the study showed that tortoises were not simply fast or slow movers. Their response times varied depending on their perception of ambiguity. This means their decisions reflected internal states, not random behavior.

Optimism predicts lower anxiety

The results showed a clear link between optimism and reduced anxiety. Tortoises that judged ambiguous cues as positive also showed relaxed behavior in stressful settings. Those with more pessimistic judgments showed hesitancy and limited head extension.

This link mirrors findings in mammals and birds. It suggests tortoises may share an emotional architecture that is much older in evolutionary terms than previously believed.

Implications for animal welfare laws

Sentience is not just a scientific question. It affects how laws treat animals. In the UK, the Animal Welfare (Sentience) Act 2022 recognizes animals’ ability to feel. This study supports the idea that reptiles should fall under such protections.

“Animal welfare concerns are reliant upon evidence that a given species has the capacity to experience affective states,” noted Anna Wilkinson, a professor of animal cognition.

“With reptiles becoming increasingly common as pets, it is essential for us to study their moods and emotions to try to understand how captivity may impact them.”

Understanding reptile emotions

The study suggests that reptiles may have a richer emotional life than once believed. While they might not show all the emotional responses seen in mammals – like strong reactions to disappointment – they still seek pleasure, value rewards, and benefit from stimulating environments.

“This is an exciting finding that represents a significant shift in our understanding of what reptiles can experience, with important implications for how we care for these animals in captivity and interact with them in the wild,” said Oliver Burman, professor of animal behavior and welfare at the University of Lincoln.

This research offers two important takeaways. First, tortoises can experience moods, not just emotions.

Second, cognitive bias tasks and behavioral anxiety tests are valid tools for studying mood in reptiles. Their responses in different contexts indicate that affective states in reptiles are real, measurable, and meaningful.

The study urges us to rethink how we house and care for reptiles. Enriched environments and opportunities for exploration can support their well-being. Recognizing their capacity for mood could also inspire more compassionate treatment.

The study is published in the journal Animal Cognition.

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