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When rats and mice break into our homes most of us would do whatever it takes to control them, but buying the wrong product could have deadly consequences on the environment.
Most consumers don’t know that Australia’s precious wildlife is dying as a result of rodenticide use, with particular active ingredients multiplying the devastation.
Birdlife Australia’s Dr Holly Parsons sat down with Yahoo News Australia to discuss how we can ensure our trip to the supermarket isn’t killing predatory birds and other critters we share the planet with.
“The issue with rat poison is that it doesn’t only kill rats and mice,” she said.
“It kills a whole range of wildlife that we value in our gardens, in our cities, and out in the bush as well."
Why some baits are more deadly than others for wildlife
If a rodent eats bait, it becomes unwell, and studies have shown that the poison can spread up the food chain and into the bodies of boobook owls, wedge-tailed eagles and other creatures.
Once the poisoned mouse is eaten by a predator, the bait will likely cause internal bleeding.
Even if the bird doesn’t die right away, traces of rodenticide can build up in their bodies, affecting them neurologically, and make them prone to car strikes and dog attacks.
Deadly second generation baits often contain brodifacoum, which once consumed takes much longer to break down in the body and can continue to build up to high levels, while less-harmful first generation products often incorporate warfarin as the active ingredient.
Yates, the manufacturer of the popular Ratsak brand, acknowledged second generation rodenticides “pose a risk” to non-target animals, but said they provide “clear warnings” on packaging in regards to active ingredients and usage.
Trying to understand which baits are more harmful
Despite manufacturers listing information on their packaging, scientists like Edith Cowan University’s Dr Michael Lohr who studies the effects on wildlife, say it’s “tricky” for consumers to understand the difference between the products.
Second generation products are highly restricted in many places overseas, including the United States and Canada, but in Australia they’re approved by our poisons regulator for retail sale by the Australian Pesticides and Veterinary Medicines Authority (APVMA).
The APVMA, a government authority, says it takes "specific aspects" of Australia's ecosystem into account, along with "use patterns", and assess the impact of poisons on animals and people.
Supermarkets have traditionally stocked both types of rodenticides side by side, although hardware giant Bunnings said they “understand the risks” second generation products pose for wildlife and are working to separate them on shelves, and better educate staff about the topic.
Woolworths did not respond directly to questions about whether they believe consumers can distinguish between products, or if they have considered providing extra information to customers, but issued a statement.
“All rodenticides sold at Woolworths must comply with standards set by the (APVMA)” it read.
“We have and will continue to consult the authority on product safety matters.
“As always, we advise customers to follow all instructions outlined on the product labelling and use it only as intended.”
Rival Coles did not respond to any questions about its sale of rat baits.
Simple tip to avoid harming wildlife when buying baits
Traps and natural rodenticides are less likely to harm wildlife, as will knowing the difference between first and second generation products and following the manufacturer's directions.
Despite concern from wildlife groups about baits, Yates argues there are some circumstances when second generation rodenticides are required, as mice and rats can become resistant to warfarin.
"We continue to invest in R&D and innovation to keep improving the safety & sustainability of our products and we are continually evaluating alternative bait solutions," a spokesperson said.
Birdlife Australia are running a campaign, urging Bunnings to take second generation rodenticides off their shelves, and are currently researching their effect on our giant powerful owls — a species increasingly being observed in our suburbs.
While second generation rodenticides remain widely available, Dr Parsons has one easy tip to avoid harming wildlife.
“One simple thing we can do is not buy rat bait,” she said.
“Leave those products on the shelves.”
The author, Michael Dahlstrom, has volunteered as a native bird carer.
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