Motunau Island

The island is an important site for seabirds. In 1967, it was the breeding site of an estimated 23,000 individual birds.^[3] It is home to a colony of 5,000 white-flippered penguins. Other birds recorded as breeding there include white-faced storm petrels, sooty shearwaters, fairy prions, variable oystercatchers and white-fronted terns.^[2][3] The island has the only colony of white-faced storm petrels found along the coast between Cook Strait and the Otago Peninsula.^[3]

Three species of lizard inhabit the island, including the species Oligosoma elium, which is considered 'Nationally Endangered'.^[2]

Fur seals use rock platforms around the island as haul-out sites.^[2][3] An elephant seal and a Hooker's sealion have also been reported on the island.^[3]

The main vegetation type on the island plateau is introduced grassland. Cliffs and scarps support grassland and herbfield. There are patches of mixed shrubland, including many introduced species.^[2]

The island has had protected status since 1935, when it became a wildlife refuge. In 1958 it was also designated a Reserve for the Preservation of Flora and Fauna. It is free of mammalian predators; rabbits were eradicated between 1958 and 1962.^[3] Threats come from introduced boxthorn plants, which impale birds and block access to burrows, as well as from human disturbance resulting from unauthorised access.^[2]