A genetic rescue of the critically endangered mountain pygmy-possum at Mt Buller

The Australian mountain pygmy possum population on Mt Buller has suffered one of the most drastic declines in numbers and genetic diversity ever documented for a mammal.

cesar is leading a team responsible for conducting Australia’s first ever genetic rescue of a wild native species population through a wild translocation.

Since the population was discovered on Mt Buller in 1996, this genetically unique population has gone through a 10 fold reduction in numbers, with less than 30 adult individuals known to exist on the mountain in 2010.

The drop in numbers has been paralleled by a drastic decline in genetic diversity. Genetic diversity is critical for the resilience and persistence of populations, especially in the face of climate change and disease.

To help improve the viability and genetic diversity of the Mt Buller population and its chance of survival, a wild translocation was undertaken in October 2010 to inject new genes into the population.

What was involved in the translocation?

Six adult males were caught at Mt Higginbotham (a population with high levels of genetic diversity) and relocated to Mt Buller.

The males were radio-tracked, recaptured and removed after four weeks, before which it was hoped the males had opportunity to breed with the Mt Buller females.

The aim of this translocation was to generate offspring resulting from matings between Mt Higginbotham males and Mt Buller females; these ‘hybrid’ juveniles would then posses a high level of genetic diversity helping to reinvigorate the population.

Did it work?

The genetic analysis from hair samples collected from trapping on Mt Buller in early 2011 confirmed the presence of one hybrid juvenile. This showed that successful breeding had occurred between the translocated males and Mt Buller females.

While further wild translocations need to take place to reach adequate genetic diversity targets, the results provide new hope for the Mt Buller population’s survival.

What does this mean for other threatened species?

“If successful it [genetic management translocation strategy] will provide a way of managing other threatened species that have lost habitat and occur in fragmented distributions throughout Australia. It could be a very effective and cheap method for saving many of Australia’s unique and endemic fauna.” Dr Andrew Weeks, Science Illustrated, June 3rd 2011.

Cover image: Photo by Andrew Weeks, Cesar Australia

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