Australia’s cane toad (Bufo marinus) is probably the invasive species to rule them all. In 1935, Australia’s Bureau of Sugar Experiment Stations (now called Sugar Research Australia), brought 102 toads from Hawaii — these were originally shipped across from South America. They were reinforcements in the fight against grey-backed cane beetles (Lepidiota frenchi) whose larvae were laying waste to sugar cane crops.
If we are to point the finger at someone for Australia’s ensuing cane toad nightmare it would be Reginald Mungomery, the organiser of the imports. The idea was that the toads would be a less environmentally destructive method of killing the cane beetle, than say DDT. His, and his colleagues', theory may have been sound, but in practice it was proven disastrously wrong (to be fair to poor Reg, the toads were said to have helped out with a similar problem in Hawaii).
Initially, the toads were released in northern Queensland, in Eastern Australia where they were heralded as a saviour. But it soon became apparent they had absolutely no interest in the cane beetles, nor their larvae for that matter. They just wanted to mate and explore their new home. They did that all too well. (It’s important to point out that even if the toads were interested in the beetles, the offending larvae lived high up on cane stalks, out of the reach of the toads. Apparently this small detail was overlooked.)
Up until the 1960’s the cane toads advanced west at about 10kms per year, but after that they accelerated to 40 to 60kms. Not only did they accelerate, but they began to evolve too. By 1978, the toads “front” had passed through most of Queensland and into New South Wales. Toads started appearing everywhere. Their merciless advance across northern Australia made them public enemy number one.
Cane toad open season was declared. Toads were gassed, shot, stabbed, run over and generally just killed by any means possible. Vigilante community groups such as the Kimberly Toad Busters popped up to keep the toads from advancing. But despite lengthy nets and all the might of the Australian public, the cane toad kept on hopping along.
In February 2009, the toads reached a landmark as they crossed the Western Australia Border with the Northern Territory. That’s a pretty incredible 2800km from where they started out and to this day they are still out there, marching on. They are said to number somewhere around 1.5 billion, but nobody is really sure.
Heralded like the arrival of a mass murderer whenever they approach, cane toads quickly became (and remain) public enemy number one. Cane toads spread so rapidly in Oz because few things eat them, and the creatures try are met with a sticky end as the toad is venomous. It secretes a pus-like cardiotoxin from glands behind its ears. Wherever the toads appeared, a spate of domestic animal deaths would occur. Native wildlife such as crocodiles and endangered quolls also suffered from eating the toads. Some entrepreneurial people who tried eating them also ended up suffering tremendously for their trouble.
Meanwhile, back in Queensland during the time that the cane toad frontier moved further and further across northern Australia, the cane beetles went about their business, totally oblivious to the alien invasion that was destined to slaughter them. They had a brief disappearance after a pesticide was introduced but after it was discovered that this was carcinogenic its use was stopped and the cane beetle came back to eat sugar cane, happy as ever.
Thus goes perhaps the most spectacularly flubbed introduction of an non-native species in history.
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