Comparative Population Genetic Structure of the Endangered Southern Brown Bandicoot, Isoodon obesulus, in Fragmented Landscapes of Southern Australia

PLoS One. 2016 Apr 20;11(4):e0152850. doi: 10.1371/journal.pone.0152850. eCollection 2016.

Abstract

Genetic connectivity is a key factor for maintaining the persistence of populations in fragmented landscapes. In highly modified landscapes such us peri-urban areas, organisms' dispersal among fragmented habitat patches can be reduced due to the surrounding matrix, leading to subsequent decreased gene flow and increased potential extinction risk in isolated sub-populations. However, few studies have compared within species how dispersal/gene flow varies between regions and among different forms of matrix that might be encountered. In the current study, we investigated gene flow and dispersal in an endangered marsupial, the southern brown bandicoot (Isoodon obesulus) in a heavily modified peri-urban landscape in South Australia, Australia. We used 14 microsatellite markers to genotype 254 individuals which were sampled from 15 sites. Analyses revealed significant genetic structure. Our analyses also indicated that dispersal was mostly limited to neighbouring sites. Comparisons of these results with analyses of a different population of the same species revealed that gene flow/dispersal was more limited in this peri-urban landscape than in a pine plantation landscape approximately 400 km to the south-east. These findings increase our understanding of how the nature of fragmentation can lead to profound differences in levels of genetic connectivity among populations of the same species.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Endangered Species*
  • Gene Flow
  • Genetic Variation
  • Marsupialia / genetics*
  • Microsatellite Repeats / genetics
  • South Australia

Grant support

This work was financially supported by the Australian Research Council Linkage grant (LP0668987) (http://www.arc.gov.au/), Native Vegetation Research Grants, Wildlife Conservation Fund Grants, the Department of Environment, Water, and Natural Resources (DEWNR) (http://www.environment.sa.gov.au), and by the Roy and Marjory Edwards Scholarship provided by Nature Foundation SA (http://www.naturefoundation.org.au). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.