Looking south from Kāpiti Island.
|Area||19.65 km2 (7.59 sq mi)|
|Length||8 km (5 mi)|
|Width||2 km (1.2 mi)|
|Highest elevation||521 m (1,709 ft)|
Kāpiti Island is a small but conspicuous island about 5 km (3 mi) off the west coast of the lower North Island of New Zealand. It is 8 kilometres (5.0 mi) long, running southwest/northeast, and roughly 2 kilometres (1.2 mi) wide, being more or less rectangular in shape, and has an area of 19.65 km2 (7.59 sq mi).
The island is separated from the mainland by the Rauoterangi channel. The highest point on the island is Tuteremoana, 521 m (1,709 ft). The seaward (west) side of the island is particularly rocky and has high cliffs, some hundreds of metres high, that drop straight into the sea. The cliffs are subject to very strong prevailing westerly winds and the scrubby vegetation that grows there is low and stunted by these harsh environmental conditions. A cross-section of the island would show almost a right-angled triangle, revealing its origins from lying on a fault line (part of the same ridge as the Tararua Range).
The island's vegetation is dominated by scrub and forest of kohekohe, tawa, and kanuka. Most of the forest is naturally regenerating after years of burn-offs and farming, but some areas of original bush with 30 m (98 ft) trees remain.
In the 18th and 19th centuries Māori settled on the island. Te Rauparaha formed a base here, and his Ngāti Toa tribe regularly sailed in canoes on raiding journeys up to the Whanganui River and down to Marlborough. In the Battle of Wairo (1824) the Ngāti Toa destroyed a force of 2,000 mainland warriors who had landed at the northern end of Kāpiti in an attempt to capture the island.
The sea nearby was a nursery for whales, and during whaling times 2,000 people were based on the island. Oil was melted from the blubber and shipped to America for use in machinery, before petroleum was used. Although whales can be seen once every year during birthing season, there still are not as many as there used to be.
The conservation potential of the island was seen as early as 1870. It was reserved as a bird sanctuary in 1897 but it was not until 1987 that the Department of Conservation (DOC) took over the administration of the island. In the 1980s and 1990s efforts were made to return the island to a natural state; first sheep and possums were removed. In an action few thought possible for an island of its size, rats were eradicated in 1998.
In 2003 the anonymous Biodiversity Action Group claimed to have released 11 possums on the island. No evidence of the introduced possums has been found.
The island is home to a number of native birds, mostly re-introduced. These include takahe, North Island kōkako, brown teal, stitchbird (hihi), North Island saddleback (tieke), tomtit (miromiro), fantail (piwakawaka), morepork (ruru), weka and North Island robin (toutouwai). The brown kiwi and little spotted kiwi were released on the island between 1890 and 1910, and the island is now the stronghold for the latter species. Rat eradication has led to increases in red-fronted parakeets, North Island robin, bellbirds, and saddlebacks, and the island is considered one of New Zealand's most important sites for bird recovery, as well as a major breeding site for sea birds. In April 2005, the critically endangered short-tailed bat was introduced to the island from a threatened population in the Tararuas, providing them with a separate, safer habitat.
Owing to the proximity of Wellington, there are regular tourist trips to the island, limited to 50 people per day, and it is an especially popular destination for birdwatchers. Having no natural mammalian predators, New Zealand birds are trusting, and a visitor to the island is likely to be rewarded by seeing a number of different species.
On 14 June 2007, one of the buildings at the Department of Conservation ranger station caught fire, sparking a major emergency operation to prevent the spread of fire to the native bush. Thirty firefighters were flown to the island and managed to contain the blaze, preventing serious damage to the ecosystem.
A stoat, an introduced mustelid responsible for decimating the bird life in New Zealand, was seen on the island in December 2010, and by August the next year the Department of Conservation had killed three of them. It is thought that they could not have swum the five-kilometre stretch of open sea from the Kāpiti Coast.
- Blundell, Kay (15 June 2007). "Mass Effort Quells Kapiti Island Fire". The Dominion Post. Retrieved 1 August 2015.
- Blundell, Kay (27 August 2011). "Kapiti Island: Stoat Finds Threat To Kiwi". The Dominion Post. Archived from the original on 25 March 2012.
- Maclean, Chris (1999). Kapiti. Whitcombe Press.
- Kapiti Island Nature Reserve, Department of Conservation
- Short-tailed bat translocation project
- Kapiti Island Nature Reserve, Nature Coast Enterprise
- Kapiti Marine Reserve
- Kapiti Visitor Information Centre