60 Australian Geographichugely important. Along with koalas in the Blue Mountains,
which have also lost much of their habitat from these fires, the
northern NSW and south-eastern Queensland koala populations
are seen as particularly important to the survival of the species.
And the reason why is that research has shown they are the
country’s most genetically diverse.T
HE REALISATION ABOUT THE genetic significance of the
northern NSW and Queensland populations grew out
of the koala genome project, which for the first time
detailed the species’ genetic makeup. This huge undertaking,
completed in mid-2018, was spearheaded by Dr Rebecca Johnson,
director of the Australian Museum Research Institute, and
involved collaboration from a large number of genetics and koala
researchers from a wide range of research bodies.
Field researchers and wildlife carers, including those at the
koala hospital, have been arguing that the conservation status of
koalas should be upgraded from vulnerable, which is currently its
status across much of the species range, to endangered. This would
provide a higher legal level of protection for known koala habitat.
But there has been a problem of perception. Koalas are plen-
tiful in Victoria and SA. “But quantity does not mean quality,”Rebecca says. “All the animals in SA and a lot in Victoria are
inbred. So they’re not the ideal populations you’d want to use to
rescue the species if it reached a highly endangered, about-to-
go-extinct scenario.” And what the current bushfire crisis has
revealed is that we certainly need to prepare for the possibility
of a natural disaster bringing on exactly that sort of scenario
with a woodland and forest species such as the koala.
Research based on the genome’s findings has identified which
koala populations would be the best to maintain to safeguard
the species. “And it’s those populations around south-eastern
Queensland, Port Macquarie and Coffs Harbour – all of those
southern Queensland and northern coastal NSW populations- that are really diverse,” Rebecca says. And those are exactly
the populations that have been decimated by the recent fires.
Some of the 26,000 genes identified in the koala genome
project also help explain the koala’s extraordinary ability to
survive almost exclusively on eucalypt leaves, a diet high in toxic
terpenes and phenols. Researchers found an abundance of genes
for bitter taste receptors, which would allow koalas to identify
the least toxic leaves, as well as genes that could detoxify the
poisonous substances. “So they have this super detox capability
that allows them to eat a highly toxic diet,” Rebecca explains.
Koalas are fussy eaters and different populations prefer the
leaves of different eucalypt species. Many Victor ian populations,
for example, love manna gums. Different northern NSW pop-
ulations choose a wider variety of eucalypt species from swamp
and grey gums to tallowwood. Different genetic capabilities in
Research based on the genome’s
findings has identified which koala
populations would be the best to
maintain to safeguard the species.
Like all koala
researchers, Dr Valentina
Mella and her team are
careful to release koalas
back to exactly the same
tree in which they were
found, taking precise
GPS coordinates to
ensure they do.Geneticist Dr Rebecca
Johnson has been thrilled
to see the landmark koala
genome, which she headed,
already being put to good
use for the purposes of
koala conservation.PHOTO CREDITS, BOTTOM LEFT: NICK LANGLEY; CLOCKWISE FROM TOP: KAREN MCGHEE