Northern quolls are dying in large numbers from cane toad ingestion, as they have no evolved aversion to this toxic amphibian introduced to Australia in 1935.
Quolls that ingest cane toads suffer acute cardiac arrest from bufadienolide toxins — death is rapid but represents preventable welfare harm for animals with no evolutionary experience of the toxin. Conditioned taste aversion through exposure to toad-sausage baits with added nausea inducer trains avoidance behaviour before release into toad-invaded areas, dramatically improving survival. This intervention directly improves welfare by converting a fatal encounter into avoidance.