Does social environment influence learning ability in a family-living lizard?
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Early developmental environment can have profound effects on individual physiology, behaviour, and learning. In birds and mammals, social isolation during development is known to negatively affect learning ability; yet in other taxa, like reptiles, the effect of social isolation during development on learning ability is unknown. We investigated how social environment affects learning ability in the family-living tree skink (Egernia striolata). We hypothesized that early social environment shapes cognitive development in skinks and predicted that skinks raised in social isolation would have reduced learning ability compared to skinks raised socially. Offspring were separated at birth into two rearing treatments: (1) raised alone or (2) in a pair. After 1 year, we quantified spatial learning ability of skinks in these rearing treatments (N = 14 solitary, 14 social). We found no effect of rearing treatment on learning ability. The number of skinks to successfully learn the task, the number of trials taken to learn the task, the latency to perform the task, and the number of errors in each trial did not differ between isolated and socially reared skinks. Our results were unexpected, yet the facultative nature of this species’ social system may result in a reduced effect of social isolation on behaviour when compared to species with obligate sociality. Overall, our findings do not provide evidence that social environment affects development of spatial learning ability in this family-living lizard.
KeywordsSquamate Sociality Cognition Ontogeny Facultative sociality
We thank G. While and M. Favre for their assistance in the field and laboratory, as well as J. Baxter-Gilbert and F. Kar for their artistic and statistical advice.
Financial support for this research was provided by the Australian Research Council (DP130102998, awarded to MJW and RWB), Natural Sciences and Engineering Research Council of Canada (scholarship to JLR), the Australasian Society for the Study of Animal Behaviour, the Australian Museum, and Macquarie University. DWAN was supported by an ARC Discovery Early Career Research Award (DE150101774) and UNSW Vice Chancellors Fellowship.
Compliance with ethical standards
Conflict of interest
All the authors declare they have no conflict of interest.
We followed guidelines for the care and use of animals as laid out by the Association for the Study of Animal Behaviour. Experimental protocols were approved by the Macquarie University Animal Ethics Committee (ARA # 2013/039). Collection of skinks was approved by the New South Wales National Parks and Wildlife Service, Office of Environment and Heritage (License # SL101264). Female skinks were captured either by hand, noosing or Eliot trap and were placed in cloth bags until they could be transported by vehicle to Macquarie University from Albury, New South Wales, in an insulated box. We observed no injuries resulting from our cognition experiment.
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