Oceania unusual biology such as the kakapo which is the world's only flightless, nocturnal, lek breeding parrot, but also many species that are similar to neighboring land areas. Some of the more well known and distinctive bird species in New Zealand are the kiwi, kea, takahe, kakapo, mohua, tui and the bellbird. The tuatara is a notable reptile endemic to New Zealand. The Pacific Islands are ruled by a tropical rainforest and tropical savanna climate. In the tropical and subtropical Pacific, the El Niño Southern Oscillation (ENSO) affects weather conditions. In the tropical western Pacific, the monsoon and the related wet
Kakapo birds. Breeding occurs only in years when trees mast (fruit heavily), providing a plentiful food supply. Rimu mast occurs only every three to five years, so in rimu-dominant forests, such as those on Whenua Hou, kakapo breeding occurs as infrequently. Another aspect of the kakapo's breeding system is that a female can alter the sex ratio of her offspring depending on her condition. A female in good condition produces more male offspring (males have 30%–40% more body weight than females). Females produce offspring biased towards the dispersive sex when competition for resources (such as food) is high and towards the