Life-history characteristics of the yakka skink, Egernia rugosa, indicate long-term social structure
Stephen Peck A F , Michael G. Gardner B E , Jennifer M. Seddon C and Greg Baxter D E
+ Author Affiliations
- Author Affiliations
A School of Geography, Planning and Environmental Management, The University of Queensland, St Lucia, Qld 4072, Australia. Present address: Queensland Parks and Wildlife Service, Charleville, Qld 4470, Australia.
B School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia, and The Evolutionary Biology Unit, South Australian Museum, North Terrace, Adelaide, SA 5000, Australia.
C School of Veterinary Science, The University of Queensland, Gatton, Qld 4343, Australia.
D School of Agriculture and Food Sciences, The University of Queensland, Gatton, Qld 4343, Australia.
E These authors should be regarded as equal senior authors.
F Corresponding author. Email: stephen.peck@npsr.qld.gov.au
Australian Journal of Zoology 64(5) 335-343 https://doi.org/10.1071/ZO16061
Submitted: 16 September 2016 Accepted: 31 January 2017 Published: 1 March 2017
Abstract
One lineage of squamates, the Egernia group, has received particular study due to stable aggregations identified in many of the species. Egernia rugosa is a large, terrestrial, viviparous skink and has been reported living communally. To investigate whether this species lives in social aggregations, we examined life-history characteristics in one population within the Mulga Lands bioregion of south-west Queensland. We found this skink used both active and inactive rabbit burrows. Parturition occurred in January/February and took several days to complete, with a mean litter size of 2.4 and a mean snout–vent length (SVL) of 84.5 mm. Six subadult age cohorts were identified. Juveniles took at least five years to reach sexual maturity and lizards had a life expectancy of >12 years. Lizards were found clustered in aggregations of up to 21 individuals (mean = 7.21) of multiple ages. An average of 50% (range = 31–67%) of all individuals within each of the age cohorts were located at their original location for two or more seasons. Dispersal was recorded for older subadult lizards. These characteristics support the hypothesis that E. rugosa aggregations comprise long-term family units; however, genetic analysis would be needed to confirm kin-based associations.
Additional keywords: aggregation, growth, longevity, population structure, reproduction, site fidelity.
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