|Area||3 ha (7.4 acres)|
|Length||300 m (1,000 ft)|
|Width||100 m (300 ft)|
|Highest elevation||25 m (82 ft)|
Motunau Island is a small, 3 ha (7.4 acres), island nature reserve lying 1.2 km (0.75 mi) off the coast of New Zealand's South Island, at the northern end of Pegasus Bay, south of the mouth of the Motunau River. The reserve is managed by the Department of Conservation and access is by permit only.
About 300 m (980 ft) long by 100 m (330 ft) wide, the island has steep sides rising to a distinctive flat top some 25 m (82 ft) above sea level. Geologically, it consists of Tertiary rocks, capped with loess and gravels, and surrounded by eroding cliffs and wave-cut reefs. The soils are extensively burrowed by nesting seabirds.
Flora and fauna
The island is an important site for seabirds. In 1967, it was the breeding site of an estimated 23,000 individual birds. 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. The island has the only colony of white-faced storm petrels found along the coast between Cook Strait and the Otago Peninsula.
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. Threats come from introduced boxthorn plants, which impale birds and block access to burrows, as well as from human disturbance resulting from unauthorised access.
- Wilson, John (14 November 2012). "Motunau Island". Canterbury places – Amberley district. Te Ara – the Encyclopedia of New Zealand. Retrieved 13 July 2013.
- "Motunau Island Nature Reserve" (PDF). Department of Conservation, New Zealand. Retrieved 13 July 2013.
- G.S. Beach, K-J. Wilson and C.A. Bannock (April 1997), A Survey of Birds, Lizards and Mammals of Motunau Island, Canterbury, New Zealand. With Emphasis on the Effects of Vegetation Change on the Breeding Success of Burrowing Seabirds, Lincoln University Wildlife Management Report 14