Response to novelty as an indicator of reptile welfare

- With a need to increase our knowledge of welfare assessment in reptiles, we investigated response to novelty in two species of reptile.
- We found this approach suitable for testing anxiety like behaviour in the red-footed tortoise.
- In contrast, bearded dragons discriminated between environments, but did not necessarily exhibit an anxiety-like response.
- We confirmed the translatability of response in one species of reptile.
- We identified species-specific behaviours that have the potential to be used in future welfare assessment.

Whilst a great deal of research has been focused on identifying ways to assess the welfare of captive mammals and birds, there is comparatively little knowledge on how reptilian species are affected by captivity, and the ways in which their welfare can be accurately assessed. The present study investigated response to novelty - a commonly used approach to assess anxiety-like behaviour and hence welfare in non-human animals - in two species of reptile with the aim of determining whether this approach could be successfully translated from use in mammalian and avian species for use in reptiles, and whether we could also identify reptile-specific and/or species-specific behaviours. Eight red-footed tortoises (Chelonoidis carbonaria) and seventeen bearded dragons (Pogona vitticeps) were observed individually in both familiar and novel environments for 10 min time periods, and their behaviour recorded. Tortoises were found to begin locomotion sooner when placed in a familiar environment than when placed in a novel environment, they extended their necks further in a familiar environment and their neck length increased over time in both familiar and novel environments, suggesting an overall anxiety-like response to novelty as seen in non-reptilian species. In contrast, whilst bearded dragons exhibited significantly more tongue-touches in a novel, compared to a familiar, environment, they showed no difference between familiar and novel environments in their latency to move. This result suggests that, whilst the dragons appeared to discriminate between the two environments, this discrimination was not necessarily accompanied by an anxiety-like response. This study has confirmed the translatability of response to novelty as an approach to assess anxiety-like behaviour in one species of reptile, as well as identifying species-specific behaviours that have the potential to be used in future studies when assessing the welfare of reptiles in response to captive environments, but our results also highlight the need to be aware of species differences within a class as diverse as reptilia.