New Zealand's kiwi (Apteryx spp.) are under severe threat from introduced predators, particularly stoats, which kill 95% of kiwi chicks on unmanaged mainland sites. Intensive predator control programs are the primary tool keeping kiwi populations from collapse.
Kiwi chicks killed by stoats experience predation stress — a sudden violent death. Adults injured by stoat attacks suffer deep bite wounds to the neck and back that frequently cause infection and mortality without veterinary treatment. In Operation Nest Egg captive rearing, welfare focuses on preventing human imprinting (which would prevent wild release), providing appropriate diet, and monitoring for disease. The use of 1080 poison is controversial: while stoat population reduction saves many thousands of kiwi, 1080 causes non-target deaths in native species including weka and kea, creating welfare trade-offs.