Does geographical isolation influence group recognition and social preference in an invasive lizard?

Katelyn Hamilton, Celine T. Goulet, Christopher P. Johnstone, David G. Chapple

Research output: Contribution to journalArticleResearchpeer-review


The formation of aggregations is fundamental to animal organization and has been shown to confer an evolutionary advantage. Conspecific attraction often prompts the formation of social groups yet not all individuals are equally attracted to others of their own species. The decision to aggregate with or avoid a particular individual is based upon class-specific signals that serve to differentiate among members and non-members. Given that signal divergence may be driven by local adaptation, disjunct populations could potentially have evolved distinct recognition systems adapted to their own ecological conditions. Several studies have shown that individuals of a species are capable of discriminating between such classes as sex, mate, kin, and familiar. Yet research exploring conspecific attraction between populations is lacking. Invasive species offer a unique opportunity to determine the consequences of geographic isolation on recognition systems and social preferences, as these genetically distinct native-range source populations have the potential to undergo secondary contact within the invaded region. To this end, we used an invasive lizard species, the delicate skink (Lampropholis delicata), to investigate conspecific recognition and attraction among individuals from two identified source populations that vary both genetically and morphologically. Our results of the dichotomous choice tests indicate that L. delicata did not differ in the level of social attraction expressed towards individuals from either population. It is unclear whether these findings are due to an inability to discriminate between local and foreign lizards using visual cues or instead that attraction is not based upon an individual's population origin but rather some other factor such as thermoregulatory requirements. Understanding the role that conspecific attraction plays in the invasion process will enable us to better predict the impacts of biological invasions. Future studies should consider using other sensory modalities and investigate the physiological benefit of grouping.

Original languageEnglish
Pages (from-to)246-253
Number of pages8
JournalJournal of Zoology
Issue number3
Publication statusPublished - Mar 2020


  • Australia
  • conspecific attraction
  • geographical isolation
  • invasive species
  • Lampropholis delicata
  • reptile
  • secondary contact
  • sympatric

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