Personality traits, defined as differences in the behavior of individual animals of the same species that are consistent over time and context, such as ‘boldness,’ have been shown to be both heritable and be influenced by external factors, such as predation pressure. Currently, we know very little about the role that early environmental factors have upon personality. Thus, we investigated the impact of incubation temperature upon the boldness on an oviparous reptile, the bearded dragon (Pogona vitticeps). Eggs, from one clutch, were incubated at two different average temperatures within the normal range. After hatching the lizards were raised under the same environmental conditions. Novel object and novel environment tests were used to assess personality. Each test was repeated in both the short term and the long term. The results revealed that incubation temperature did impact upon ‘boldness’ but only in the short term and suggests that, rather than influencing personality, incubation temperature may have an effect on the development of behavioral of oviparous reptiles at different stages across ontogeny.

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 minute 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 anxietylike 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.

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