Stoats introduced to New Zealand have devastated native bird populations, requiring intensive eradication programs that raise welfare questions about lethal control of intelligent mustelids.
Stoat eradication in New Zealand is considered essential for the survival of multiple endangered bird species. Current control methods including aerial 1080 sodium fluoroacetate drops cause prolonged painful deaths over hours. Leg-hold traps cause distress before killing. Conibear kill traps provide faster death when properly set. The welfare of individual stoats being controlled must be weighed against the population-level welfare of kakapo, kiwi, and other species they predate. The stoat fertility control program under development would be a major welfare advance if successful. Stoat intelligence means traps must be regularly modified to prevent them learning to avoid known designs. Island eradications of stoats have been successfully completed on some islands with significant bird recovery.