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Australian Environmental Issues

Blue-tongue
A true-blue battler

Box jellyfish
How to avoid the stings and what to do if stung

Crocodile
So you wrestle crocs...

Dingo
Unfairly judged in killing off the thylacine?

Echidna
The wise little gnomes of Australia

Emu
Victors of the great Emu war

Flies
Shaping everything from how Australians speak to how they salute

Funnel Web spider
Yyou'll never leave your ugg boots outside

Kangaroo
Most herbivores don't grow a spine until they are the size of an elephant. Not so the roo.

Snakes
Kill less people than cows

Shark attack Australia
How to ensure you don't go by the name of Bob

Tasmanian Devil
The solution to mainland extinctions?

Tasmanian Tiger
A sad tale

Wombat
Keg of muscle

Quoll
The mainland's largest marsupial carnevore

Mythical creatures
Yowies and dropbears; some say they are myths but those who are not afraid to talk have shared their stories

 

 

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Rabbits invading Australia

Failed Rabbit Controls in Australia

The history of the rabbit in Australia demonstrates that people can be really silly. In 1859, a farmer introduced 24 grey rabbits to remind him of home. At the time, the man wrote:

"The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."

By 1900, the rabbits had reached plague proportions and were causing extreme environmental damage. They ring-barked trees, ate fields to oblivion and caused massive soil erosion by digging burrows.

While the introduction of the rabbit was on the silly side, some of the attempts to control the rabbit have been even more intellectually challenged. One of the early methods was to build a 1,833 km long fence to keep rabbits out of Western Australia. It was quite optimistic thinking to believe that it was ever going to keep out the singular pregnant female that would make it obsolete.

.State Barrier Fence of Western Australia

The idea of fences to keep rabbits out of a state has always been a joke to some. NSW was sensible enough not to create one. WA wasn't.

Work commenced in 1901 but rabbits were found west of the fence by 1902. Nevertheless, work continued and the fence was completed by 1907. After the first rabbits got through, it would be expected that the Western Australian government would have conceded the stupidity in their idea. Instead, it repeated it. In 1905, commenced work on a second fence stretching 1166 kilometres further west. Despite harsh penalities for anyone who left gates open, the fence again failed to stop the single pregnant female that made it through. Work then commenced on fence number 3. Admittedly, as a face-saving exercise, the purpose of the fences 3 was redefined as intended to stop dingos following the rabbits to the wheat belts. When the government wised up to how stupid that sounded, it was redefined as necessary to stop emus heading to the wheatfields, which it did...sort of. Ironically, in the Great Emu War of 1932, the federal government called in the army to use machine guns on emus because emus were accused of knocking over the rabbit-proof fences letting rabbits through.

State Barrier Fence of Western Australia emus

Although the rabbit-proof fence was not rabbit proof, it did kill a lot of emus.

With fences proving as useless as expected, the next attempt at control was the myxoma virus. When it was first introduced in the 1950s, the virus killed up to 99 per cent of rabbits without infecting any other species. From a perspective of economics, the myxoma virus was a resounding success; estimated to have added billions to Australian agricultural output. From a perspective of native Australian animals; however, the virus was problematic. By temporarily removing rabbits from ecosystems, large numbers of predators, such as quolls, eagles, foxes, cats, and goannas, turned their attentions to small marsupials, such as bilbies, which were hunted into extinction before the predators also saw their numbers decline. Fast breeding myxomatosis immune rabbits subsequently migrated into ecosystems ravaged by myxomatosis. In comparison to what they once had been like, these ecosystems had few competitors for the rabbit, and even less predators. Paradoxically, the final outcome was in the rabbit's interests and biodiversity was actually decreased by trying to eliminate rabbits.

Perhaps the series of catastophes on Macquarie Island best shows of the environmental damage that has been caused by a obsessive desire to kill rabbits without considering that there may be collateral damage. Macquarie Island is a 34km by 5km island halfway between Australia and Antarctica. Cats and rabbits were introduced in 1860s to provide food if sailors were shipwrecked.  Overtime, the two species formed a balance with each other.

That balance was interrupted in the 1960s when the myxomatosis virus was introduced to reduce rabbit numbers. Each time a virus outbreak decimated rabbit populations, the cats started hunting native birds. In the 1990s, scientists gained $500,000 in funding to eliminate a population of only around 500 cats that had been on the island for almost a century and a half. When the final cat was removed in 2000, rabbit numbers were somewhere between 4,000 and 20,000. Within 6 years, the population had reached 130,000 and Macquarie Island's vegetation was being eaten to extinction.

(Left. Macquarie Island before the removal of cats. Right, after the removal.)

 

In 2011, $26,000,000 was spent trying to remedy the disaster. The first stage of the plan involved releasing another virus, the rabbit calicivirus, which had an average kill rate of around 90%. The second stage involved using helicopters to drop 307 tonnes of brodifacoum baits for the rabbits that survived the virus. This was around 3 tonnes of bait for every square kilometre. The third stage involved hunters and dogs searching the island for the next seven years with burrow bombs, and poisons to kill the rabbits that were expected to have survived the virus and baits.

The virus and baits were released in July 2011. By December 2011, hunters had caught a further 13 rabbits that had survived the virus and baits. One of these rabbits was a female that had bred.

Before the poisoning began, scientists conceded that the collateral damage of their rabbit control programs would include a significant number of the local bird population that either ate the baits or the poisoned bodies of the dead rabbits. Although the scientists predicted the death of birds, they didn't predict that, upon the elimination (or virtual elimination) of rabbits, Macquarie Island would be overrun with invasive weeds that were previously eaten by the rabbits. Furthermore, they didn’t predict a 90 per cent die back of the native Azorella plant. One scientist explained explained it as a possible side affect of dropping three tonnes of a very nasty chemical on every square kilometre.

On Macquarie island, the scientists' choice of poison was brodifacoum. On the mainland, the preferred choice is 1080 poison, a synthetically produced substance that is a replication of a naturally occurring poison found in plant species such as poison bush. Although native animals can eat the foliage, seeds and flowers of the plants with no ill effect, it is deadly on the feral animals that have not evolved alongside it.

1080 is a slightly better control method than a virus and brodifacoum because as well as rabbits being killed, poisons can be made for cats and foxes as well. In this way, both predators and rabbits can be removed. Nevertheless, it is still results in a shock to the ecosystem and only temporarily removes the ferals until more migrate in to take their place. Furthermore, not all native animals have been exposed to poison bush thus 1080 can kill native animals as well.

Contrary to stereotypes, the rabbit isn't a great competitor and is not ideally suited to Australian conditions. Unlike marsupials, it isn't a great conserver of energy, it can't control its breeding to adapt to drought conditions, it isn't able to eat the diversity of food as can competitors like the bilby, and it is not as mobile through potted terrain as are hoping marsupials. On Kangaroo Island, goannas have actually eaten them to extinction.

The rabbit's only real advantage is that it is a fast breeder so can quickly fill voids when the ecosystem is in a state of imbalance or predators are low in numbers. It is just a shame that by trying to help the native animals, or protect lambs on sheep farms, humans are actually helping rabbits. If humans wouldn't interfere, the rabbit would probably go extinct in Australia just as it has gone extinct on Kangaroo Island and is in danger of extinction in many parts of the world. In areas of Australia that aren't subjected to continous fox, cat, and rabbit eradication programs, rabbit numbers are actually very low and do the little harm that the English settler originally envisaged.

 

Invasive ferals

Carp

Carp and Trout
A tale of two ferals

New hope for Cane Toads
The many unknown predators of the toad

Rabbits
A fence almost 2,000 km long to keep rabbits out of WA? Sounds like a great idea! If it doesn't work, we'll build another one!

The Willow
How a change in its status from asset to weed led to fish kills with blackwater and blue-green algae outbreaks

To bait dingos?
Should the health of the ecosystem be considered or just the kennel club registration?

Koala control
What to do about the "koala plague" on Kangaroo Island

Cat
Apex predator in Australia. Confined to urban areas in America.

Environmental values

Environmental problems
How money and ideology shapes environmental "science."

Bushfire
Australia's Stockholm Syndrome with gum trees.

The Kangaroo industry
Should we eat skippy?

Climate change in Australia
Australia was once covered in rainforest. Could it be again?

Sustainability
The dark side of sustainable environmental policies

Native pets
Why no pet wombats?

 

 

       

Australian environmental science is defined by an ideology that is not unlike a prison warden. There, the scientists are not seeing themselves as part of the ecosystem, but as masters over it; protecting the rights of the species that they say have rights and killing those that they say do not…but inevitably killing both.

"It was always seen as desirable to remove or cull the introduced species. We also need to ask whether it was possible to do so, how it should be done, whether it could have unintended consequences and what it would cost? I don't think anyone really asked those questions." Physicist John Reid - 2012