Overview
Uninhabited, with almost no human influence, this remote paradise is home to more than 55 species found nowhere else on earth. These include four unique land-birds: the Henderson fruit-dove, Henderson lorikeet, Henderson rail and Henderson reed-warbler. The island, a global stronghold of the gadfly petrel group, is also the only known breeding site of the endangered Henderson petrel.
The island's beaches provide crucial nesting habitat for endangered marine turtles. Combine this with nine plant species, eight species of snail and dozens of invertebrates all endemic to this island, and it is clear that Henderson is one of the crown jewels of UK biodiversity. It is a designated World Heritage Site, making it one of the planet's greatest natural assets.
Despite being remote and uninhabited, Henderson’s unique biodiversity is currently under threat due to the presence of introduced Pacific rats. Evidence from fieldwork has shown 95 per cent of petrel chicks are killed within just one week of hatching (more than 25,000 chicks a year). Since petrels lay only one egg in a clutch, this level of predation is simply unsustainable.
Seabird numbers have dropped from an estimated 5 million pairs before rats arrived to just 40,000 pairs. The Henderson petrel is being driven towards extinction. The rats are also likely to be reducing populations of marine turtles and other wildlife on Henderson.
During August-September 2011, the RSPB, in conjunction with the Pitcairn Islands Government, undertook a ground-breaking operation to restore Henderson Island. At 43 square kilometres, Henderson was the largest tropical or sub-tropical island ever to be subject to a rat eradication operation, and the third largest island yet treated in the world. The project was also the first time an aerial eradication operation had been conducted from the deck of a ship.
However a monitoring expedition confirmed that rats are unfortunately still present on Henderson Island. There is more work to do to save Henderson's unique wildlife.
