Does social environment influence learning ability in a family-living lizard?
- 555 Downloads
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.
Supplementary material 2 (MOV 73617 kb)
- Bonnett MP (1999) The ecology, behaviour and genetic relationships of a population of Egernia striolata. Unpublished Honours thesis, Flinders University of South Australia, Adelaide, AustraliaGoogle Scholar
- Bustard HR (1970) A population study of the scincid lizard Egernia striolata in northern New South Wales. Proc K Ned Akad Wet C 73:202Google Scholar
- Cogger HG (2014) Reptiles and amphibians of Australia, 7th edn. CSIRO Publishing, ClaytonGoogle Scholar
- De Vosjoli P, Ferguson G (1995) Care and breeding of Panther, Jackson’s, Veiled, and Parson’s chameleons. i5 Publishing, Los AngelesGoogle Scholar
- Dobson AJ, Barnett A (2008) An introduction to generalized linear models. CRC Press, Boca Raton, pp 45–66, 229–256Google Scholar
- Ehmann H (1992) Encyclopedia of Australian animals: reptiles. Angus and Robertson, SydneyGoogle Scholar
- Gelman A, Carlin JB, Stern HS, Rubin DB (2014) Bayesian data analysis, vol 3. Chapman and Hall/CRC Press, Boca RatonGoogle Scholar
- Kruschke J (2014) Doing Bayesian data analysis: a tutorial with R, JAGS and Stan. Academic Press, CambridgeGoogle Scholar
- Plummer M, Best N, Cowles K, Vines K (2015) Coda: output analysis and diagnostics for MCMC. R package version 0.13-3. http://CRAN.R-project.org/package=coda
- Post MJ (2000) The captive husbandry and reproduction of the Hosmer’s Skink Egernia hosmeri. Herpetofauna 30:2–6Google Scholar
- R Core Team (2016) A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna. https://www.R-project.org/
- Shettleworth SJ (2010) Cognition, evolution, and behavior, 2nd edn. Oxford University Press, New YorkGoogle Scholar
- Swanson S (1976) Lizards of Australia. Angus and Robertson, Sydney, p 43Google Scholar
- Zurr AF, Hilbe JM, Ieno EN (2013) A beginner’s guide to GLM and GLMM with R: a frequentist and Bayesian perspective for ecologists. Highland Statistics Ltd, NewburghGoogle Scholar