NATUR E
July–August 2015 19ILLUSTRATION BY KEVIN STEAD
T
HE LEADBEATER’S POSSUM,
one of the world’s most
endangered marsupials, is
in a perilous position, which is why
the federal government followed
the advice of scientists in April and
listed it as critically endangered.
Along with the helmeted honeyeater,
it is one of Victoria’s state faunal
emblems, an honour bestowed on
this adorable-looking nocturnal
creature in 1971.
Leadbeater’s possum was already
rare when it was discovered in South
Gippsland in 1867. Up until 1909,
only six specimens had been collected
and by the time of the 1939 Black
Friday fires it was presumed to have
died out. It was officially declared
extinct in the 1950s, but the listing
was premature, because in 1961
naturalist Eric Wilkinson discovered
a small colony 100km east of
Melbourne, at Marysville.
Today, the Leadbeater’s possum
persists primarily within forests of
mountain ash trees (the world’s tallest
flowering plant) in Victoria’s Central
Highlands. For its survival, this small
marsupial requires nest holes in the
hollows of living or dead old-growth
trees, which are typically more than
190 years old. From these hollows,
nesting colonies – each led by a
dominant matriarch – venture out at
night to forage on the sap of wattles,
and on insects that live in the bark
streamers of ash trees.
Clear-felling of mountain ash has
taken a heavy toll on Leadbeater’s
possum and logged areas remain
unsuitable for more than 150 years
after they are cut. The 2009 Black
Saturday bushfires also dealt a
devastating blow, destroying 45 per
cent of suitable possum habitat. In
addition, logging has increased the
severity of fire in harvested andIn the tiny patch of Victoria that the Leadbeater’s possum
calls home, logging has destroyed most of the mature tree
hollows the species needs to survive.
Logged into oblivion
regenerated forests (as younger trees
can lead to fierce ‘canopy’ fires),
which has contributed to the absence
of animals from burnt forests.
The change to the conservation
listing of the species this year follows
a damning letter – authored by
Australian professors David
Lindenmayer and Hugh Possingham,
and published in 2013 in the prestig-
ious international journal Science. The
respected pair of experts accused the
Victorian State Government of
choosing to log forests in ways that
accelerate the loss of large old trees,
rapidly leading to the demise of
the state emblem.
“Government-sanctioned
legal logging of the reserve
system will significantly increase
the chance of extinction,” the
scientists wrote. “To the best of our
knowledge, and despite state and
national threatened species legislation,
this is the first time an Australian
government has taken calculated
actions to substantially reduce the
viability of an IUCN-listed endangered
species with full knowledge of the
likely consequences.”
The problem now, says David,
who is based at the Australian
National University in Canberra, is
that most of the suitable old-growth
trees with hollows have gone and the
possums can’t wait another 70–
years for them to grow back. His
computer modelling work suggests
there’s a 92 per cent chance that
within 50 years the species’ habitat
will irretrievably collapse – meaning
it won’t be able to provide what its
inhabitants need to survive.
As readers of this journal
will know, the rediscovery of
‘extinct’ Australian species- such as the night parrot,
bridled nail-tail wallaby and
mountain pygmy possum – is not an
uncommon occurrence, and one that
reflects the fact that we have so many
perilously endangered species. But, in
most of these cases, swift actions have
been taken by state and federal
governments to aid in the survival of
these creatures.
To find out how you can donate to
help Zoos Victoria and the Friends of
Leadbeater’s Possum conserve this
fragile species, turn to page 117 for the
details of our Leadbeater’s possum
fundraising appeal.JOHN PICKRELL is the
editor of AUSTRALIAN
GEOGRAPHIC. Follow him
on Twitter at: twitter.com/
john_pickrell圀漀爀氀搀䴀愀最猀⸀渀攀琀圀漀爀氀搀䴀愀最猀⸀渀攀琀
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