Nature & Wildlife

New research reveals rat and mice poisons killing endangered owls

New BirdLife Australia research has revealed rat and mice poisons are having a devastating impact on endangered Powerful Owls.

The analysis tested liver samples of deceased Powerful Owls for the presence of anticoagulant rodenticide chemicals used in common household rat and mice baits. The disturbing findings revealed:

  • 37 of the 38 samples showed an anticoagulant rodenticide (AR) was present
  • The most common rodenticide present was brodifacoum. Brodifacoum is the most persistent AR registered for use in Australia and is the most common one used in rat poisons available on hardware and supermarket shelves
  • nearly 60% had levels high enough to cause impairment. This likely puts these birds at greater risk of other threats such as being hit by vehicles.  
  • 10% had levels high enough to kill the bird outright.

Anticoagulant rodenticides work by causing internal bleeding in animals that consume them. Unlike first generation products, second-generation anticoagulant rodenticides (SGARs) kill not only the rats and mice they are targeting, but also any bird or other animal that might eat a poisoned rodent. 

“These results are yet more evidence that we need to stop selling second generation rodenticide products to consumers,” said BirdLife Australia Urban Bird Program Manager Dr Holly Parsons.

“The samples tested in this research were largely collected prior to this year’s mouse plague, so what we are seeing is indicative of contamination from baits used by householders during normal periods.

“I shudder to think what impact might be playing out in our native wildlife now from eating rodents that were baited during the plague.”  

Powerful Owls are a threatened species that live across the eastern seaboard, including in the suburbs of Brisbane, Melbourne and Sydney. Other research has already revealed rodenticide poisoning impacts on Boobook owls, Tasmanian devils and quolls.

BirdLife has launched a petition to Bunnings asking them to voluntarily remove second generation anticoagulant rodenticides from their shelves. While other major Australian hardware retailers also sell some rat poisons, Bunnings has the most SGARs on its shelves by far.  

“We don’t think these products should be available for use by anyone except licensed professionals, similar to regulations already in place in the EU and Canada,” said Dr. Parsons.  

“But so far the regulatory authority in charge, the Australian Pesticides and Veterinary Medicines Authority, has failed to act.

“Until they do, we are calling on major retailers to do the right thing and take these products off their shelves.”

Analysis of the test results was conducted by Edith Cowan University and Wildlife Analytics Western Australia. More information about BirdLife’s campaign is available at https://www.actforbirds.org/ratpoison