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 kakapo is believed to employ bacteria in the fore-gut to ferment and help digest plant matter. Kakapo diet changes according to the season. The plants eaten most frequently during the year include some species of "Lycopodium ramulosum", "Lycopodium fastigium", "Schizaea fistulosa", "Blechnum minus", "Blechnum procerum", "Cyathodes juniperina", "Dracophyllum longifolium", "Olearia colensoi" and "Thelymitra venosa". Individual plants of the same species are often treated differently. Kakapo leave conspicuous evidence of their feeding activities, over feeding areas that range between and per individual. Kakapo feeding grounds almost always host manuka and yellow silver pine ("Lepidothamnus intermedius") scrubs. Fossil records indicate that in