News reports from New Zealand indicate the 5 new Kakapo parrots have hatched, raising the total population to 91. The Kakapo, Strigops habroptilus, is a nocturnal flightless parrot found only in New Zealand.
“A certain combination of traits makes it unique among its kind—it is the world’s only flightless parrot, the heaviest parrot, nocturnal, herbivorous, it sports visible sexual dimorphism in body size, has a low basal metabolic rate, no male parental care, and is the only parrot to have a polygynous lek breeding system. It is also possibly one of the world’s longest-living birds.” (Wikipedia)
New Zealand has more flightless birds than any other country: this includes the Takahē, five species of Kiwi, several species of penguin, two species of teal, the weka and several extinct wrens, nightjars and moas. Why does New Zealand have so many flightless birds? The reasons involve the lack of land predators, the lack of competing animals and the fairly recent arrival of humans . Lack of predators allows birds to stay earthbound, and the lack of mammals allowed the birds to fill niches that mammals would have normally have taken. The islands were probably initially populated by birds on the wing, entering a habitat without competitors and with few predators. The wings, as tools to escape or obtain food, had less use and because flight has a relatively high energy cost the evolution of flightless species could result.
(Corrections made 11 April, 2008)