Résumé
An animal’s social environment can be both dynamic and complex. Thus,
social species often garner fitness benefits through being plastic in
their social behavior. Yet, social plasticity can be constrained by an
individual’s experience. We examined the influence of early social
environment on social behavior in the tree skink (Egernia striolata), a
family-living lizard. In the first phase of this study, we reared
juveniles in two different social environments for 1.5 years: either in
isolation or in unrelated pairs. We quantified each lizard’s sociability
at four-month intervals using a standardized laboratory assay, and found
that isolated lizards were more sociable, spending the assay closer to an
adult female, than socially-reared lizards. In the second phase of this
study (at the end of 1.5 years), we released all lizards into a
semi-natural environment, observed their associations, and used social
network analysis to quantify social behavior. During the initial six weeks
post-release, we detected no differences in social behavior between
rearing treatments. However, during the following six months differences
emerged. Isolated lizards were more homogeneous in the strength of their
associations than socially-reared lizards. Also, at first, isolated
lizards associated more strongly than socially-reared lizards. Over time,
isolated lizard associations became weaker and involved fewer lizards. In
contrast, the level and number of associations of socially-reared lizards
were stable over time. Our findings suggest that early experience
influences tree skink social behavior but does not constrain social
plasticity: isolation rearing did not limit their ability to respond to a
novel social environment.