ABC Western Queensland is carrying the
following story that reports anecdotal evidence that the Cane Toad is the cause
of increased mortality in Varanus populations of the Cooper drainage. This is unedited.
20 January, 2011
3:37PM AEST
Cane toads in the Cooper threaten predators
By Nicole Bond and
Julia Harris
Cane toads first
arrived at Noonbah station homestead near Stonehenge, in March last year,
although they were seen at a neighbouring property, Lochern, about six months
earlier. Now, with a boom season in the district, the toad numbers are
increasing, and Angus Emmott, a grazier and naturalist said he's starting to
see their impact on goannas. He said the cane toads are just breeding like
crazy.
"There's young
ones everywhere but there's also lots of big ones," he said.
The issue of concern
to Mr Emmott is he's now noticing that the goannas in particular are starting
to die at Noonbah.
"I'm seeing
goanna bodies lying around and anything like mulga snakes, De Vis banded
snakes; any of those animals that have frogs as a significant component of
their diet are really going to be hammered," he explained.
Mr Emmott said he
hasn't seen a dead goanna with a cane toad in its mouth but the evidence from
northern Australia is overwhelming.
"When the cane
toads first move in, you get a mass die off of these particular groups of
animals."
The promising part
for Mr Emmott seems to be that over a period of about 20 years, the few goannas
that do survive gradually learn to live with the cane toads and leave them
alone.
He's hoping that will
occur in the Cooper system over time as well.
"But we've
probably got 15 to 20 years to wait until the goanna populations come back up
to any sort of numbers again," he explained.
He said the goannas
and other frog eating animals have a major role in the balance of the ecosystem
and that's going to change.
"But without
close, intense study we're probably not even going to be aware of what exactly
those impacts are."
A number of
scientists are interested in the invasion of cane toads into the Lake Eyre
Basin catchments, and Mr Emmott said it's because it wasn't something that was
predicted.
"It was thought
that this part of the world would be too arid for them.
"They seem to be
adapting quite well to the aridity; although it's not very arid at the moment!
"Sydney Uni had
a student working around the Longreach area last summer and I'm sure if they
can get some more money together they'll be doing some more work," said Mr
Emmott.
Labels: Australia, Rhinella marina, Varanus