At night, a kiwi calling, then its mate replying - heard but not seen. The kiwi have been reintroduced to the area after being locally extinct for decades. They are free to roam, feed, breed etc without human intervention, but are surrounded by a fence to protect them from introduced predators. The fence is not designed to keep them in (and other flighted birds reintroduced to the sanctuary come and go as they please), but as kiwi can't fly none have left the area!