Behavioral Ecology and Sociobiology

, Volume 63, Issue 7, pp 1045–1056 | Cite as

Network structure and parasite transmission in a group living lizard, the gidgee skink, Egernia stokesii

  • Stephanie S. GodfreyEmail author
  • C. Michael Bull
  • Richard James
  • Kris Murray
Original Paper


Gidgee skinks (Egernia stokesii) form large social aggregations in rocky outcrops across the Flinders Ranges in South Australia. Group members share refuges (rock crevices), which may promote parasite transmission. We measured connectivity of individuals in networks constructed from patterns of common crevice use and observed patterns of parasitism by three blood parasites (Hemolivia, Schellackia and Plasmodium) and an ectoparasitic tick (Amblyomma vikirri). Data came from a 1-year mark-recapture study of four populations. Transmission networks were constructed to represent possible transmission pathways among lizards. Two lizards that used the same refuge within an estimated transmission period were considered connected in the transmission network. An edge was placed between them, directed towards the individual that occupied the crevice last. Social networks, a sub-set of same-day only associations, were small and highly fragmented compared with transmission networks, suggesting that non-synchronous crevice use leads to more transmission opportunities than direct social association. In transmission networks, lizards infested by ticks were connected to more other tick-infested lizards than uninfected lizards. Lizards infected by ticks and carrying multiple blood parasite infections were in more connected positions in the network than lizards without ticks or with one or no blood parasites. Our findings suggest higher levels of network connectivity may increase the risk of becoming infected or that parasites influence lizard behaviour and consequently their position in the network.


Social networks Lizards Parasite transmission Group-living 



We thank two anonymous reviewers for constructive comments on an earlier version of this manuscript. This research was funded by grants from the Australian Research Council. The ARC/NHMRC Research Network for Parasitology Travel Award supported a research exchange to the University of Leeds and the University of Bath. We thank Professor Jens Krause and members of his research group for valuable discussions about this research. The study was conducted according to the guidelines of the Flinders University Animal Welfare Committee in compliance with the Australian Code of Practice for the use of animals for scientific purposes. All procedures carried out in this study conformed to the current laws of Australia.

Supplementary material

265_2009_730_MOESM1_ESM.doc (63 kb)
ESM Summary table of GLM analysis of factors influencing parasite infection status of ticks, Hemolivia, Schellackia, Plasmodium and the total number of blood parasite species (no. parasite species). Wald χ 2 /F values, df and P values in bold were remaining in the final minimal model after backward stepwise deletion of non-significant terms. All other non-significant values given were at the time of their deletion from the model (DOC 61.0 KB).


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Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Stephanie S. Godfrey
    • 1
    Email author
  • C. Michael Bull
    • 1
  • Richard James
    • 2
  • Kris Murray
    • 1
    • 3
  1. 1.School of Biological SciencesFlinders UniversityAdelaideAustralia
  2. 2.Department of PhysicsUniversity of BathBathUK
  3. 3.The Ecology Centre, School of Integrative BiologyUniversity of QueenslandQueenslandAustralia

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