Second-generation anticoagulant rodenticides used to control rats and mice cause widespread secondary poisoning of owls, raptors, foxes, and other predators that consume poisoned rodents, creating significant wildlife welfare concerns.
Secondary rodenticide poisoning of wildlife represents a diffuse, widespread welfare harm that is chronically underestimated. The barn owl found dead near farm buildings, the kite that falls from the sky — these individual deaths represent considerable suffering from internal bleeding, weakness, and progressive haemorrhage that may take days. The scale is significant: survey data suggests that the majority of apex predators tested in rodenticide-heavy agricultural areas carry detectable liver residues. The welfare irony is that many of the animals killed are themselves important rodent predators — barn owls, kestrels, and red kites — whose death removes natural rodent control that reduces the need for chemical intervention. Reducing rodenticide use through better integrated pest management, physical proofing, and restricting consumer access to SGARs benefits wildlife welfare directly.