Here is the ABC's version of the story (below).
As I see it the trigger is land clearance and habitat fragmentation, plus
the spread of lantana. If you have a small patch of bush with a lantana
understorey in some or all of it, you will get Bell miners. In undisturbed
areas bell miners aren't all that common.
Cheers
Graham Turner
Bellbird blamed for destruction of eucalypt forests
AM - Monday, 4 December , 2006 08:21:00
Reporter: Sabra Lane
TONY EASTLEY: In the eucalypt forests stretching from Melbourne right
to Brisbane, their call is the quintessential sound of the Australian bush.
But some residents say if you hear the call of a bellbird, that could
well herald a forest in peril. The bellbird, or bell miner as it's known, is
being blamed for killing thousands of hectares of bush on the east coast.
Dieback is a condition in which trees progressively die from the top
downward. The condition spreads through the leaves and branches, and
eventually often the whole plant then dies. So bad is the problem on the far
south coast of New South Wales, the birds are being caught and killed.
AM's Sabra Lane reports.
(Sound of a bellbird's call)
SABRA LANE: That is the call of the bellbird. The unattractive looking
native brown birds appear harmless enough, but wildlife experts warn
bellbirds, or bell miners, are becoming a major ecological problem.
JIM SHIELDS: I well recall when I first heard them and it's a magical
sound. It's a subject of a poem by Australia's first forester. The bellbirds
singing, singing, singing, and it's a beautiful sound.
SABRA LANE: I can hear them in the background there now.
JIM SHIELDS: Yes, you can. If I stepped outside the door, you could
hear the colony that's in the gully down from my house that's been gradually
moving up the hill. At the moment, the trees are healthy except for the ones
right in the centre of the colony, which would have begun to show signs of
dieback.
SABRA LANE: That's Dr Jim Shields, a wildlife manger, who consults
with New South Wales Forestry and National Parks. He explains why the birds
are being fingered as the culprits of a major dieback of eucalypt forests.
JIM SHIELDS: The bell miner is, the colonies where they live, are
often filled with dead and dying trees. As time progresses, and the colonies
get bigger and bigger, this has been a relatively recent phenomena and
causal factors are truly unknown, but it is definitely a fact that where
there are large colonies of bell miners, the trees decline in health.
This is because the bell miners exclude other birds and the
leaf-eating insect populations get out of balance, and eventually if enough
leaves are eaten, the trees become unhealthy and expire.
SABRA LANE: In some areas, the birds are in plague proportions. The
population in some areas has gone from none to 20,000 over 20 years.
Among ecologists, this phenomenon even has a name, Bell Miner
Associated Dieback, or B-MAD.
JIM SHIELDS: It's a significant problem but not, at the moment, not an
environmental catastrophe. There would be hundreds to thousands of hectares
affected depending on how big an area you look at.
The problem goes from Melbourne in Victoria, right up to Brisbane, all
along the south-east coast and there would be thousands of hectares involved
of declining or dying forest.
SABRA LANE: On the south coast of New South Wales, near the coastal
town of Merimbula, the problem has become so bad that one property owner
sought permission to kill the birds.
It's believed to be the first large-scale cull of the animals.
JIM SHIELDS: We've caught them in nets, we use a RSPCA-approved method
of euthanasia, C02 gas when the birds go to sleep, and we have worked over
the past 18 months to carry out that program.
The first signs of success have begun appear about six months into the
program when the colonies were solely occupied by bell miners, were
reoccupied by other native species.
SABRA LANE: But Dr Shields says this trial has been costly for the
private landowner. A national group is now looking at other, cheaper ways of
managing the bellbird problem.
TONY EASTLEY: Sabra Lane reporting.
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