Easily accessible rat poison continues to decimate native owl population

Rat poisons which can be bought at the supermarket have been detected in the livers of dead owls across the country and are thought to be one of the leading factors in the decline of owls in recent years. Despite the reported dangers, the poisons have remained on sale, with conservationists concerned potential restrictions will not be implemented any time soon. Second-Generation Anticoagulant Rodenticides, or SGARs, are poisons sold with the guarantee of one dose, one kill. However, the poisons do not break down inside the body for up to nine months — meaning the toxins are having an impact on native animals, Owl Friendly Margret River Region’s Dr Boyd Wykes said. He said though the poison can kill a mouse or rat with a single dose, it can take up to a week for the infected animal to succumb. During this time, mice and rats are able to ingest more than one dose, making them a “hand grenade” able to deliver multiple doses to a single animal unfortunate enough to eat the infected animal. Birdlife Australia’s Dr Holly Parsons said the impact extends far beyond the South West, with the powerful owl species living on the East Coast being a prime focus of Birdlife’s investigation into the impacts of these poisons. She said 37 of 38 powerful owl livers tested as part of their study showed rat poison in their system. A similar study on southern boobook owls in the South West revealed 92 percent of owls had similar traces in their system, Dr Wykes said. Dr Wykes said no one was going to take the products off their shelves while it’s still legal to sell them, but the use of SGARs is currently under review with the Australian Pesticides and Veterinary Medicines Authority. A spokesperson for the APVMA said it is the organisation’s responsibility to ensures all chemicals used for agricultural or veterinary purposes, sold and used inside of Australia, are safe. “The APVMA commenced a reconsideration of anticoagulant rodenticides in 2021,” the spokespersons said. “Should evidence emerge in relation to a role for a substance to pose an undue hazard to non-target species, the APVMA would take that into consideration in determining appropriate regulatory action.” Publication of the proposed regulatory decision on anticoagulant rodenticides is expected in September 2024. Despite this, Dr Wykes is concerned as there was no guarantee the organisation will agree to restricting the use of the poison. Dr Parsons said while an owl may not die outright from the poison, they have a cumulative impact on the owl’s health, making them more susceptible to other dangers. “Because they are unwell, and not hunting clearly and are likely to take more risks to get food,” she said. In response to the dangers of these poisons, the US state of California banned the sale of SGARs on the open market in 2020. The United Kingdom is also strapping down on the toxin with the use of some SGARs set to become illegal from July 4 this year. Dr Parsons said it is incredibly frustrating to see these poisons still available at shops despite the growing international evidence showing their dangers. “If you do need to deal with an infestation there are other options out there,” she said. “The general snap trap is a nice easy way to get rid of rats and mice and you know they’re taken out of the food chain and don’t risk poisoning anything else.”