Abstract for presentation at Biodiversity Extinction Crisis Conference - A Pacific Response

A case study of threatening processes and management for the boodie, Bettongia lesueur

  • Felicity Donaldson, School of Animal Biology, The University of Western Australia, Australia
  • Keith Morris, Depatment of Environment and Conservation, Australia
  • Dr Roberta Bencini, School of Animal Biology, The University of Western Australia, Australia
  • Dr Philip Vercoe, School of Animal Biology, The University of Western Australia, Australia

    • The boodie (Bettongia lesueur) population on Boodie Island can be considered as a case study of three threats to biodiversity: competition from non-endemics, consequences of management, and demographic isolation. Boodie Island is approximately 170ha with a single endemic mammal species – the boodie. In the 1980s the extermination of boodies by competition from introduced rats (Rattus rattus) was seen as inevitable as the number of boodies had been reduced to less than 50. The Department of Conservation and Land Management (now Department of Environment and Conservation) took action to poison the rats and accepted the risk of poisoning the remaining boodies. Rats were eradicated but the boodie population was also lost. A recovery program to repair ecological function on Boodie Island involved the reintroduction of 36 boodies from neighbouring Barrow Island. The loss of genetic biodiversity from Boodie Island in the form of local adaptations was irreparable, however, this outcome was considered acceptable (though not ideal) due to the impending demise of the population had the rats not been removed. The extirpation of boodies was due to an interaction of threatening processes: if rats were not present drastic management would not have been necessary, and without the island’s natural isolation the effects of management would not have resulted in a total loss of local adaptation. A recent survey of the re-introduced population has shown that neutral genetic diversity has been lost relative to the donor population, but this has not negatively affected the fitness of the population. An average of 0.7 alleles have been lost per microsatellite locus and heterozygosity has been reduced from 0.66 to 0.57, but there is no significant difference in fluctuating asymmetry or female reproductive output between the Boodie Island and Barrow Island populations. Management priorities for Boodie Island are to maintain quarantine and regular monitoring.

    Conference Organiser - ICMS Pty Ltd