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 affectionate pet by the Māori. This was corroborated by European settlers in New Zealand in the 19th century, among them George Edward Grey, who once wrote in a letter to an associate that his pet kakapo's behaviour towards him and his friends was "more like that of a dog than a bird". The conservation of the kakapo has made the species well known. Many books and documentaries detailing the plight of the kakapo have been produced in recent years, one of the earliest being "Two in the Bush", made by Gerald Durrell for the BBC in 1962. A feature-length documentary,