Kākāpō live safely on islands free from predators. It means we need to constantly safeguard those islands from the ongoing threat of predator invasion – and that’s a costly business.
Anchor Island is within swimming distance of the mainland for stoats, so we maintain a network of stoat traps on the island and surrounding islets, constantly monitoring the islands for any activity.
Codfish Island (Whenua Hou) and Hauturu (Little Barrier Island) are not prone to stoat invasion, but have been home to the kiore, or the Pacific rat. So, in 1998, the Department of Conservation undertook a huge rat eradication programme to remove kiore from Codfish (1400ha) and did the same on Hauturu (3000ha), in 2004.
It meant that we had to remove all the kākāpō and other vulnerable species, and then spread rat poison over the islands, by helicopter.
Today, both islands remain predator-free. They are the largest islands available to support viable populations of kākāpō beyond the swimming range of kākāpō predators.
But the existence of cats, dogs, dogs, possums, ferrets, stoats and rats on either the mainland or Stewart Island, prevent kākāpō being released elsewhere.