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Social environment impacts behavioural development of a family-living lizard
thesisposted on 2022-03-28, 01:43 authored by Julia L. Riley
For group-living animals social experience during ontogeny is known to influence multiple facets of animal behaviour. Rearing social animals isolated from any conspecific contact can hinder development of behavioural traits, cognitive ability, and social competence. This thesis is an overview of how social environment effects behavioural development in a family-living lizard, Egernia striolata. I experimentally manipulated E. striolata early social environment,and raised skinks either in isolation or in pairs. I began by examining if social environment impacts development of skink behavioural traits across their first year of life. I found strong evidence that skink behavioural development was plastic depending on their social experience, and isolation itself did not hinder E. striolata behaviour in a similar manner as found in previous research. I then assessed how social isolation impacted skink cognitive ability. Contrary to previous research, I found no effect of social environment on individual learning ability in multiple cognitive tasks (e.g., spatial, motor and discrimination tasks). Additionally, juvenile tree skinks did not use social information from adults regardless of their early social environment. Finally, I studied if social environment affects skink social competence using repeated behavioural observations in a laboratory and semi-natural setting. I found that isolated skinks were initially more social than socially-raised skinks, but they decreased in their sociability over time once exposed to a social environment. This is evidence that E. striolata can flexibly alter their social behaviour in response to the environment they are exposed to, even after long-term social isolation. Overall, this thesis presents evidence that isolation rearing does not consistently result in negative impacts on behaviour across all social taxa, and instead, that E. striolata behavioural development responds flexibly, and potentially adaptively, to the social environment in which they are raised.