Kiwi survival in New Zealand depends entirely on intensive predator management, with stoats, rats, and cats causing near-total chick mortality in unmanaged mainland areas.
Kiwi welfare is inseparable from predator management because the primary welfare threat — predation by introduced mammals — causes acute suffering and death to millions of kiwi over ecological time. Stoat predation of chicks involves pursuit, capture, and killing of highly vulnerable young birds. Predator control using 1080 poison, traps, and aerial operations has welfare implications for non-target species, but the counterfactual — uncontrolled predation killing the majority of kiwi chicks annually — represents a far greater welfare harm. Operation Nest Egg, while intensive and involving significant human handling, achieves chick survival rates that transform individual welfare outcomes at the population level. Predator-proof island sanctuaries provide environments where kiwi can express their natural nocturnal foraging behavior, territorial vocalizations, and social interactions in safety — a meaningful welfare improvement over mainland populations living under constant predation pressure.