The kakapo was once common throughout most of New Zealand, occupying anything from lowland forests to mountain grasslands. They are now extinct on the mainland. Kakapo can now only be found on three offshore islands: Codfish, Maud, and Little Barrier Islands. These islands are reserves, with no predators except for kiore, Polynesian rats. All predators, such as cats, rats, stoats, and dogs on the islands were killed off to prevent them from wiping out the kakapos. Kakapo live off the roots, seeds, fruits, bulbs, buds, flowers, leaves, cones and pollen of dozens of different plants. Their diet varies according to which food plants are available. Except for the kereru, they are New Zealand's only herbivorous birds.