Invasive species cause enormous ecological and welfare harm to native wildlife. Management programs must balance welfare of invasive animals against protection of native species.
Invasive species management creates an inherent welfare tension: allowing invasive species to continue causes welfare harm to native species they predate and compete with, while removing them through lethal control causes welfare harm to the invasive animals themselves. This tension has no clean resolution — it requires weighing the welfare of different individuals and populations against each other. Where feasible, non-lethal alternatives including fertility control, deterrence, and biological control offer welfare advantages. Island eradication programs that protect bird populations from introduced predators save many lives at the cost of others. Welfare-informed management seeks to minimize suffering in all species while achieving necessary ecological protection.