Early social environment affects development of behavioural traits in a lizard (#263)
Early social environment plays an important role in shaping behavioural and physiological development in many vertebrates. In birds and mammals, young raised in isolation exhibit impaired learning and social behaviours, but effects of isolation rearing are largely unknown in reptiles. Tree skinks (Egernia striolata) are a viviparous lizard that can live in family groups. We hypothesized that social rearing environment may play an important role in shaping lizard behaviour, and predicted that along the bold-shy axis, isolation-reared individuals would be less exploratory and bold, but more aggressive than individuals raised socially. We allocated offspring born to females in the lab to two treatments immediately post-birth: those raised (1) solitarily, and (2) in pairs. We assayed behavioural traits four times throughout a juvenile’s first year. Trials consisted of: (1) introduction to a novel environment (to measure exploratory behaviour); (2) being presented with a ‘predator’ (boldness); and (3) being presented with a lizard model (aggressive behavior). Preliminary analyses indicate that lizards raised in a social environment are more exploratory than lizards raised alone, but are no different in their boldness or aggression. The removal of social interaction during juvenile development in E. striolata does not appear to have as strong an effect as it does in species with an obligate social system (e.g., primates, elephants). We will discuss the hypothesis that the weaker effect we observed may be due to the facultative nature of E. striolata sociality.