Kakapo low. Supplementary feeding affects the sex ratio of kakapo offspring, and can be used to increase the number of female chicks by deliberately manipulating maternal condition. During the winter of 1981, only females lighter than were given supplementary feeding to avoid raising their body condition, and the sex ratio results in 1982 were close to parity, eliminating the male-biased sex ratios in the unrestricted feeding. Today commercial parrot food is supplied to all individuals of breeding age on Whenua Hou and Anchor. The amount eaten and individual weights are carefully monitored to ensure that optimum body condition is maintained. Kakapo
New Zealand parrot the phylogeographical dynamics of this family. The kakapo is a flightless, nocturnal species, well camouflaged to avoid the large diurnal birds of prey on the island, while the local owls are too small to prey on the kakapo at night. The kakapo is the only flightless bird in the world to use a lek-breeding system. Usually, they breed only every 3–5 years when certain podocarp trees like rimu ("Dacrydium cupressinum") mast abundantly. The kea is well adapted to life at high altitudes, and they are regularly observed in the snow at ski resorts. As trees are absent in the alpine