Auckland's Rangitoto and Motutapu islands have been declared pest-free, and will now become home to two of the country's rarest birds.
During the past three years the Department of Conservation (DoC) has spent $4.6 million on eradicating pests from the islands.
It removed all trace of rats, mice, stoats, feral cats, hedgehogs and rabbits. Wallabies and possums had already been eradicated, in the late 1990s.
Conservation Minister Kate Wilkinson on Saturday released takahe and tieke (saddleback) after an official blessing from local iwi, DoC said.
Over the next five years the islands will also become home to a variety of other species, including kiwi and tuatara.
The Department of Conservation is asking all visitors to check their boats and kayaks before entering the water to ensure the islands remain a safe home for the wildlife.