“Napalming” the mice plague in NSW with deadly poison could see nearby Indigenous communities become sick, scientists warn.
Concern in growing among many Kamilaroi people in northern NSW after the state government announced plans this month to kill the rodents with bromadiolone, a second generation rodenticide which persists in tissue once ingested.
The deadly poison is not usually used in large quantities across broad acre farms, as the NSW government is seeking to do, because unlike readily available alternatives it is known to enter the food chain.
If the plan goes ahead, researchers predict local extinctions of native animals as they prey on mice.
Affected predatory birds will likely die within five to eight days of consuming baited rodents.
Reptiles pose a greater threat to human health as they are believed to have a higher tolerance for the poison; they can consume several sick rats without getting immediately sick and then pass on the bait when eaten as bush tucker.
Rodenticides create 'serious human health concerns'
Edith Cowan University’s Dr Michael Lohr is particularly concerned about goanna consumption as it is widely eaten by Indigenous people across Australia.
“The tissues where (the poison) accumulates, the liver and fat, are actually a preferred portion of the animal to eat.”
He believes there are alternative poisons which could be just as effective.
Mr Lohr's colleague, PhD candidate Damian Lettoof, said once ingested the poison interfered with the body's production of vitamin K and can affect blood clotting.
"If you eat enough contaminated animals you will suffer the full effects of the anticoagulant poison," he added.
"If you only have a small amount... there's some research that has shown in mammals that it can interrupt your immune system."
Indigenous woman frightened by government poison plan
Communities with large Indigenous populations – including Moree, Coonabarabran, Coonamble and Narrabri – have been confirmed as planned poisoning sites by Agriculture Minister Adam Marshall.
“It’ll be the equivalent of napalming mice across rural NSW,” Mr Marshall told the ABC earlier this month.
Mr Marshall and the NSW Department of Agriculture have been contacted for comment.
Goannas, known as yurrandaali, are revered by the Kamilaroi people as a totem and used for traditional purposes.
Local native title applicant Polly Cutmore said the oil was prized amongst her people, noting it had improved the health of two severely sick relatives. News of the poisoning plan “frightens” her.
“This is just really scaring me. It’s a prized food and medicine in our tribe," she said.
Concern for fish if mouse poison plan given green light
Kamilaroi man Alfred Priestley said he often ate goannas as part of a diet that rejects most “white fella food”.
“With these goanna I eat everything. The only thing with a goanna I don’t eat is in his intestine, I clean all that out,” Mr Priestley said.
“I don’t miss a thing, I even eat the bones."
Another Kamilaroi man Mick Horne has observed eagles too full to move from their branches after feasting on mice.
Fish too he says are eating rodents, which he saw firsthand during a trip across his country.
“I said have a look at this, the mice are starting to cross the river, and the next minute we saw the cod circling around, just grabbing them," he said.
“If the mice are full of poison the cod fish are going to to be next."
Weather change will see mouse plague end, locals say
Mr Priestly believes authorities need to show patience.
“What happens when a human panics? They want to kill everything," he said.
“But as soon as you kill it you just bring something worse.”
He believes the mice will leave once the weather changes and this is consistent with scientific analysis of the situation.
“These people are telling stories about waking up and the mice are in their bed; it’s because the mice like to keep warm,” Mr Priestly said.
“As soon as the cold comes, you’ll be down to a normal population.”
Poison could enter livestock, researchers fear
While mice and wildlife are likely to be directly affected first, researchers believe the poison could also impact livestock.
Mr Lettoof said testing in Perth, where rodenticide is allowed in residential settings, found the poison in every snake and lizard.
“We also found trace amounts of rat poison and tiger snakes in living in wetlands, that we're surrounded by urban areas, but still... six hundred metres away from housing,” he said.
“You’d presume a snake that mostly eats frogs that lives in a wetland isn’t going to have rat poison in it.”
Ongoing studies, he added, indicate rodenticides are “saturating the entire food web”.
“Now we're getting more and more research showing that it doesn't just end up in mice or mice predators, it ends up in everything," he said.
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