Population structure of the yellow-footed rock-wallaby Petrogale xanthopus (Gray, 1854) inferred from mtDNA sequences and microsatellite loci

Authors

  • L. C. POPE,

    Corresponding author
    1. Centre for Conservation Biology and Department of Zoology, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
      Fax: + 612-7-365-1655; e-mail: c.moritz@mailbox.uq.oz.au
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  • A. SHARP,

    1. Centre for Conservation Biology and Department of Zoology, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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  • C. MORITZ

    1. Centre for Conservation Biology and Department of Zoology, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
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  • This project formed part of Lisa Pope's honours project, supervised by Craig Moritz. Andy Sharp is completing a PhD on the ecology of the yellow-footed rock-wallaby at the Hill of Knowledge (named as such by the local ranger, Col. Morgan). The development of the microsatellite primers is part of a larger project to develop primers that could be used across a range of macropod species.

Fax: + 612-7-365-1655; e-mail: c.moritz@mailbox.uq.oz.au

Abstract

The yellow-footed rock-wallaby Petrogale xanthopus is considered to be potentially vulnerable to extinction. This wallaby inhabits naturally disjunct rocky outcrops which could restrict dispersal between populations, but the extent to which that occurs is unknown. Genetic differences between populations were assessed using mitochondrial DNA (control region) sequencing and analysis of variation at four microsatellite loci among three geographically close sites in south-west Queensland (P. x. celeris) and, for mtDNA only, samples from South Australia (P. x. xanthopus) as well. Populations from South Australia and Queensland had phylogenetically distinct mtDNA, supporting the present classification of these two groups as evolutionarily distinct entities. Within Queensland, populations separated by 70 km of unsuitable habitat differed significantly for mtDNA and at microsatellite loci. Populations separated by 10 km of apparently suitable habitat had statistically homogeneous mtDNA, but a significant difference in allele frequency at one microsatellite locus. Tests for Hardy-Weinberg equilibrium and micro-geographical variation at microsatellite loci did not detect any substructuring between two wallaby aggregations within a colony encircling a single rock outcrop. Although the present study was limited by small sample sizes at two of the three Queensland locations examined, the genetic results suggest that dispersal between colonies is limited, consistent with an ecological study of dispersal at one of the sites. Considering both the genetic and ecological data, we suggest that management of yellow-footed rock-wallabies should treat each colony as an independent unit and that conservation of the Queensland and South Australian populations as separate entities is warranted.

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