Cane Toad Threat to Australia's Wildlife.
Originally Published
in 1987 in THE HERPTILE 12 (3) pp. 86-87, as well as HABITAT,
WILDLIFE AUSTRALIA and several Australian newspapers.
Dear Sir,
One of the greatest ongoing threats to Australia's herpetofauna remains
largely ignored.
It is the Cane toad (Bufo marinus).
These grotesque toads were originally introduced in 1935 from their native
Americas, in the mistaken belief that they would Control the Grayback Cane
Beetle (Demolepida albohirtum); they have overrun the entire state
of Queensland, and are systematically eliminating most forms of wildlife
(directly or indirectly).
The toads eat anything that is small enough to fit into their mouths. They
are highly poisonous (skin secretions/glands) so whatever eats them also
dies. The venom is so toxic that reptiles and other animals are often found
dead with the toads still in their mouths. These losses are then passed
up the 'food chain', so that the end result is that most carnivores are
dying out. The herbivores, such as wallabies etc., are no longer subject
to predation so invariably one species becomes dominant at the expense
of all others (thereby usually causing the extermination of all other species).
Frog-eating, snakes seem to have borne the brunt of the 'toad invasion'.
A number of formerly very common snakes have new disappeared from areas
where the toads occur, these include the Death Adder (Acanthophis
antarcticus, A. praelongus) the Tiger Snake (Notechis
scutatus) and the Red-bellied Black snake (Pseudechis
porphyriacus).
Specifically an estimated thirty species of native frogs are already extinct,
some possibly still unknown to science. A similar number of species in
Queensland face imminent extinction unless the toad is erradicated immediately.
Massive numbers of reptile species (including those that kill vermin such
as rats and mice) are dying out and even the so-called beautiful native
animals (Tiger cats, the rare coastal wallabies etc.) are, indirectly,
under threat from the toads.
And this is only Queensland.
The worst is yet to come. The toads are now moving out in all directions
and are a threat in parts of the Northern Territory and NSW. The toads
will, if not checked overrun most parts of mainland Australia within sixty
years and consequently destroy an enormous part of our wildlife. World
Heritage areas each as Kakadu (N.T.) will be meaningless if destroyed by
the toads.
Introduced water buffaloes trampling over swamp vegetation and wiping out
frogs and crocodile nests are already making a mockery of wetland conservation
in this area.
No governmental (Federal, State or local) or Wildlife authority have taken
any actions to eliminate the toad. In order to minimize the damage already
caused, the Australian authorities should invest what would be peanuts
and eradicate them from Australia before they eliminate what wildlife remains
and ruin what native and semi-native bushland is left.
I hope that by publishing this letter, your journal will help to inform
non-Australians of a major threat to our herpetofauna and the generally
lax attitude most Australians have towards many conservation issues.
Raymond Hoser,
170 Lawson Street,
Redfern, NSW, 2016
And after 14 years of effective official inaction - we get the next installment in this sorry saga via an AAP media release - see below:
Authorities understating toad's effect on Kakadu says zoologist
Source: AAP|Published: Wednesday March 14, 2001, 1:14 PM
Leading zoologist and crocodile expert Grahame Webb today accused authorities of hypocrisy in understating the impact of cane toads on Kakadu National Park.
The Department of Environment and Heritage confirmed yesterday that the first toads had been found on Monday within the boundaries of the World Heritage-listed park.
National Parks director Peter Cochrane said there would be ecological consequences but no species was expected to be lost.
Professor Webb, a Northern Territory University zoologist and director of Wildlife Management International, said authorities were understating the likely damage.
"The impact is going to be a lot more negative than some people are letting on," he said.
"It's like saying the Holocaust wasn't a problem because the Jews didn't go extinct.
"There's a hypocrisy in the fact we put people in jail for having a pet lizard or snake but won't accept that there's a major problem with large-scale reductions of species."
He expected toads would have an impact on both fresh and saltwater crocodiles.
He said the public had a right to be told how much the predicted impact of toads in Kakadu was based on fact and how much was guesswork.