New Zealand kiwi have survived five million years of predator-free evolution and face welfare and extinction risk from introduced predators that their behavior offers no protection from.
Kiwi welfare from predator attack involves terror and traumatic death for animals that have no behavioral capacity to recognize or evade the threat. Their evolutionary history without mammalian predators left kiwi without flight, speed, or evasion behaviors — defenses that other birds developed in response to predation pressure. A stoat entering a kiwi burrow encounters an animal that cannot fight, flee, or even recognize the danger. The welfare harm of this evolutionary mismatch is severe and ongoing, affecting the entire remaining kiwi population outside managed areas.