Rodents are threatening the unique natural environment of Australias sparsely populated Lord Howe Island. But a plan to eradicate the pests by dropping 42 tonnes of poisoned cereal is dividing the close-knit community in half
Described by the UN as a zone of spectacular and scenic landscapes, Lord Howe Island is nothing if not dramatic. Formed from an inferno of underwater volcanoes more than six million years ago, the 10 km long crescent-shaped island sits in a bath of turquoise water, exactly where the warm East Australian Current meets the icy waters of the Antarctic Circumpolar Current.
Those ancient lava flows left a rugged landscape with steep cliffs, which drop off into an ocean which supports the worlds most southerly coral reef. Between those cliffs and the reef lies a calm blue lagoon that laps against a yellow-sand beach.
But now theres difficulty in paradise.
Listed as a world heritage site, Lord Howe Island is home to hundreds of species of plants and animals found nowhere else in the world, along with 350 people who, isolated from Australias mainland by 600 km, form a close-knit community.
That little community is being torn apart. By rodents. Or rather, what to do about the rodents that are threatening that unique environment.
A plan drafted in 2009 to fell 42 tonnes of poisoned cereal on the island to eradicate it of mice and rats has divided the community in half.
Years of bitter conflict about whether to progress with the eradication led to a poll in May last year referred to on the island as the referendum in which 48% of respondents voted against pursuing government approval for the eradication. And the disagreement is fierce.
The journey to this split involves shipwrecks, the worlds largest stick insect, the psychology of small islands and a touch of conspiracy. The scenario, still playing out on the island, is shown how preservation can be as much a social science as an ecological science.
Until about 1860, Lord Howe Island was free of mice and rats. Then, somehow or other, mice were introduced. They began to eat native bugs and plants and compete for food with native birds. But their impact on the native plants and animals is not completely clear.
Then on 15 June, 1918, the SS Makambo, a steamship carrying fruit and vegetables, ran aground. It was repaired and refloated within 10 days, but not before black rats scurried off the ship and set up home on their new island paradise.
That was the beginning of the end for several unique animals. Over the coming years, the rats are thought to have caused the extinction of five species of bird and 13 invertebrates that arent discovered anywhere else in the world.
Today rats continue to threaten 13 more birds and two species of reptiles.
But somewhat strangely, one uncharismatic animal has grabbed the spotlight and focused international attention on the 14.55 sq km Australian island and its big rat problem.
The Lord Howe Island stick insect also known as the Lord Howe Island phasmid or tree lobster was presumed extinct. The largest stick insect in the world, it was a regular dinner for hungry rats, and within two years of the invasion, sightings of the once common insect had ceased.
But in 2001, based on a hunch, a squad of scientists scaled a premonition rocky outcrop 23 km south-west of the island called Balls Pyramid, where it was unlikely rats had colonised. After scaling the mount and not seeing any of the phasmids, the scientists resigned themselves to heading home empty-handed.
On their descent they discovered droppings that seemed too large to be from any other bug and decided to return at night when the phasmids were known to be active. When they came back, they found a small colony of 24 living there.
After 81 years of extinction, the phasmids were back.
Two years later, after a revival scheme had been established, the team returned and took a breed pair, named Adam and Eve, to Melbourne zoo.
Now were in our 12 th generation from the original pair says Rohan Cleave from Melbourne zoo, who manages the breeding program. Last week we hatched our 13,000 th baby nymph thats the number that hatched since 2003, when we hatched our first ones.
The early couple of weeks were really stressful. Not knowing anything about the species except one particular bush they might have feed, Cleave says. But were here hatching them almost every day in 2016.
Now, bred back from the verge of extinction, the phasmids are being flown around the world. Last year the latter are flown to a zoo in Bristol and one in Toronto. And this year a group were flown to San Diego for breeding. Besides being a unique exhibit for those zoos, they act as insurance in case something happens to the collecting at Melbourne zoo, explains Cleave.
Although theyre jet-setting around the world, they cant go home to Lord Howe Island yet, says Cleave. Thats always been the hope from the start of the program, he says.
There are some in enclosures on the island where the stick insects are breeding, but until the rats are gone, this strange, ancient animal cannot live free.
Not everyone is a fan of the phasmid.
It infests houses and feeds crops. Its a nuisance. Its ugly. Ugly and frightening, says Rob Rathgeber, a resident on the island who has been a vocal opponent of the rat eradication. Rathgeber is retired now but has a science degree and was a businessman.
Rathgeber doesnt want the phasmid back. Despite what the scientists say, hes not persuaded the rats killed it in the first place. And hes deep worried about the health impacts of a rat eradication program that spreads poison across the island. Hes concerned by the proposed utilize of aerial baiting where poisoned pellets are thrown from helicopters.
This stuff is going to rain down on the island. Its going to come on to our rooftops. Its going to be in the soils, he says.