Humans have been poisoning rodents for centuries. But fast-breeding rats and mice have evolved resistance to earlier poisons. In response, manufacturers have produced second generation anticoagulant rodenticides such as bromadiolone, widely used in Australian households.

Unfortunately, these potent poisons do not magically disappear after the rodent is dead. For example, it’s well known owls who eat poisoned rodents suffer the same slow death from internal bleeding.

Our new research, published in the journal Science of The Total Environment, shows the problem is much bigger than owls. We found Australia’s five largest marsupial predators—the four quoll species and the Tasmanian devil—are getting hit by these poisons too.