Island pest eradication involves killing invasive rats, stoats, and cats to protect native wildlife. The welfare tradeoffs between target species and the native wildlife they threaten are complex.
Pest eradication involves killing large numbers of invasive animals using methods that cause varying degrees of welfare harm. Brodifacoum poisoning causes prolonged internal bleeding over multiple days — a welfare-poor killing method that is nonetheless effective at island-scale eradication. Non-target casualties including native species add individual welfare harms beyond the target population. Community snap trapping causes more rapid death and fewer non-target casualties but requires ongoing maintenance rather than a single eradication event. The welfare calculus — harm to individual invasive animals weighed against recovery of entire native species and ecosystems — is how conservation managers justify eradication, but individual welfare harms to target species are real regardless of this calculus.