Holocene extinction may have put some pressure on other birds but at the time of early European contact (18th Century) and colonisation (19th Century) the bird life was prolific. With them, the Europeans brought ship rats, possums, cats and mustelids which decimated native bird life, some of which had adapted flightlessness and ground nesting habits and others had no defensive behavior as a result of having no extant endemic mammalian predators. The kakapo, the world's biggest parrot, which is flightless, now only exists in managed breeding sanctuaries. New Zealand's national emblem, the kiwi, is on the endangered bird list. There has been
Kakapo from her nest to a food source up to away and the male may walk from its home range to a mating arena up to away during the mating season (October–January). Young birds indulge in play fighting, and one bird will often lock the neck of another under its chin. The kakapo is curious by nature and has been known to interact with humans. Conservation staff and volunteers have engaged extensively with some kakapo, which have distinct personalities. While they are curious toward humans, kakapo are not social birds. The kakapo was a very successful species in pre-human New Zealand,