Kakapo the reason for its massive decline since the introduction of dogs, cats and mustelids (see "Conservation: Human impact"). The kakapo is the only species of flightless parrot in the world, and the only flightless bird that has a lek breeding system. Males loosely gather in an arena and compete with each other to attract females. Females listen to the males as they display, or "lek". They choose a mate based on the quality of his display; they are not pursued by the males in any overt way. No pair bond is formed; males and females meet only to mate. During
The Mockery Bird population of Mockery Birds still live in the valley! Peter's discovery attracts the attention of the world press, environmentalists, politicians and businessmen from all around the world, and this leads to a couple of adventures. Finally, Professor Droom, a biologist, discovers that the main and only agricultural product of Zenkali, the Amela tree is ecologically linked to the Mockery Birds (explained below), so the flooding of the valley will make the island's economy collapse. Consequently, the construction of the airport is cancelled. The fictitious bird species of the book, the Mockery Bird is a flightless bird about the size of