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
Flightless cormorant bird eventually became flightless. Indeed, wings trapping air among flight feathers are likely to have been a disadvantage to the cormorants which dive from the surface. However, since their discovery by man, the islands have not remained free of predators: cats, dogs, and pigs have been introduced to the islands over the years. In addition, these birds have no fear of humans and can easily be approached and picked up. In the past, introduced feral dogs were a great threat to the species on Isabela, but they have since been eradicated from the island. Future introduction of rats or cats