Fossil records indicate that in pre-Polynesian times, the kākāpō was New Zealand s third most common bird. However, their numbers have declined by 80 per cent in the past 100 years. They are the heaviest parrot species in the world with females weighing around 1.4 kg, and males 2.2 kg. The country’s kākāpō population currently lives on just four predator-free islands – Codfish Island/Whenua Hou, Te Hauturu-o-Toi/Little Barrier Island, Chalky Island/Te Kakahu, and Anchor Island. With no predator-free islands big enough to accommodate them, the only option is for DOC to find an island and then eradicate the pests.