Henderson Island (Pitcairn Islands)

Henderson Island

UNESCO World Heritage Site
Map of Henderson Island
Criteria	Natural: vii, x
Reference	487
Inscription	1988 (12th Session)

Henderson

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Location of Henderson Island in the Pacific Ocean

Henderson Island (formerly also San João Baptista and Elizabeth Island) is an uninhabited raised coral atoll in the south Pacific Ocean, that in 1902 was annexed to the Pitcairn Islands colony, a South Pacific Dependent Territory of the United Kingdom. Measuring 9.6 kilometres (6.0 mi) long and 5.1 kilometres (3.2 mi) wide, it has an area of 37.3 square kilometres (14.4 sq mi) and is located 193 kilometres (120 mi) northeast of Pitcairn Island at 24°22′01″S 128°18′57″W. The island was designated a World Heritage Site by the United Nations in 1988. It is unsuitable for agriculture and has little fresh water. There are three beaches on the northern end and the remaining coast comprises steep, mostly undercut, cliffs up to 15 metres (49 ft) in height.

History

Archaeological evidence suggests that a small permanent Polynesian colony lived on Henderson at some time between the twelfth and fifteenth centuries. The reasons for the group's disappearance remain unknown, but may relate to the similar disappearance of the Polynesians on Pitcairn Island, on whom the Hendersonians would have depended for many of the basics of life. The Pitcairn Polynesians may in turn have disappeared because of the decline of nearby Mangareva; thus, Henderson was at the end of a chain of small, dependent colonies of Mangareva.

On 29 January 1606 the Portuguese sailor Pedro Fernandes de Queirós discovered Henderson Island and named it San João Baptista. On 17 January 1819 the British Captain Henderson of the British East India Company ship Hercules re-discovered the island and named it Henderson Island. On 2 March 1819 Captain Henry King, sailing aboard the Elizabeth, landed on the island to find the king's colours already flying. His crew scratched the name of their ship into a tree, and for some years the island's name was Elizabeth or Henderson, interchangeably.

The crew of the wrecked Nantucket whaleship Essex landed briefly on the island, staying from 20 to 27 December 1820. Three of the crew – Thomas Chappel, Seth Weeks and William Wright – stayed and survived until their subsequent rescue on 9 April 1821, while their companions sailed on for South America in three whaleboats. The castaways reported having seen human skeletons in a cave.

In August 1851 visitors from Pitcairn Island also found skeletons in a cave and wreckage on the adjacent beach. After a party of Pitcairners collecting miro wood rediscovered the skeletons in March 1958, a medical examination determined that the bones were of Caucasian origin, and they were then buried in a shallow grave inside the cave. Finally, an American survey team examined the bones in 1966 and buried them in five coffins in the left-hand corner of the cave, tightly jamming a large cross between the ceiling and the rock floor at the entrance. They concluded the remains were of five or six people, one of whom was between three and five years of age. It is presumed they were the survivors of a shipwreck who died of dehydration.

Henderson Island shelter.

In 1957 a twenty-seven-year-old American, Robert Tomarchin, lived the life of a castaway on the island for approximately two months, accompanied by a pet chimpanzee, apparently as a publicity stunt, until people from Pitcairn rescued him in two longboats.

In the early 1980s American businessman Arthur M. Ratliff expressed interest in establishing a small settlement with an airstrip, cattle ranch, and mansion on the island. The Pitcairn Island Council approved his plans in April 1981 but the British Foreign and Commonwealth Office overrode the decision and vetoed the proposed development, after environmentalist groups had lobbied to protect the natural ecology and environment of the island. Henderson Island was subsequently listed as a World Heritage site in 1988.

Natural resources

Since the introduction of aluminium-hulled long-boats in the 20th century, Pitcairners have made regular trips to Henderson to harvest the wood of miro and tou trees. Usually they only venture to Henderson once per year, but may make up to three trips if the weather is favourable. Pitcairners carve the wood into curios, from which they derive much of their income.

Geography

The Pitcairn Islands

Henderson Island is a raised coral atoll that, with Pitcairn, Ducie and Oeno Islands, forms the Pitcairn Island Group. The nearest major landmass is more than 5,000 kilometres away. This coral limestone island sits atop a conical (presumed volcanic) mound, rising from a depth of roughly 3500 metres. Its surface is mostly reef-rubble and dissected limestone; an extremely rugged mixture of steep, jagged pinnacles and shallow sink holes, and the island is encircled by steep, undercut limestone cliffs on all but the north end. There are three main beaches, on the north-west, north, and north-east sides, and the north and north-west sides are fringed by reefs. The depression at the island's centre is thought to be a raised lagoon. There is only one known potable (drinkable) water source, a brackish spring, exposed briefly at neap tide. The surrounding ocean rises about one metre at spring tide.

Flora

Pandanus tectorius

Apart from five species found bordering the beaches, including coconut palms, the vegetation is undisturbed. Henderson Island is covered by 5–10 m tall tangled scrub forest, more thinly covered in the central depression. It has 51 native species of flowering plants, ten of which are unique to the island (endemic). Dominant tree species include coconut, Pandanus tectorius, Thespesia populnea, Tournefortia argentea, Cordia subcordata, Guettarda speciosa, Pisonia grandis, Geniostoma hendersonense, Nesoluma st.-johnianum, Hernandia stokesii, Myrsine hosakae, and Celtis sp.

Fauna

The Henderson Lorikeet (Vini stepheni), also known as the Stephen's Lorikeet, is a species of parrot in the Psittacidae family, endemic to Henderson Island.

Birds

The island is home to four currently extant endemic land bird species – the Henderson Fruit Dove, Henderson Lorikeet, Henderson Reed Warbler and the flightless Henderson Crake. 3 species of the Columbidae family were formerly endemic to the island, but became extinct when the Polynesians arrived around 1000 CE, the Henderson Ground Dove(Gallicolumba leonpascoi), Henderson Imperial Pigeon (Ducula harrisoni), and theHenderson Archaic Pigeon (Bountyphaps obsoleta) Of the fifteen non-endemic seabird species found, nine or more are believed to breed on the island. Breeding colonies of the globally endangered Henderson Petrel formerly existed on Ducie, but were wiped out by invasive rats by 1922. It is believed to now nest uniquely on Henderson island. The island has been identified by BirdLife International as an Important Bird Area for its endemic landbirds and breeding seabirds.

Bones associated with prehistoric Polynesian occupation sites dating to somewhere between 500 and 800 years ago include those of the Polynesian Storm Petrel, Marquesan Imperial Pigeon, and Polynesian or Pacific Imperial Pigeon which are no longer found on the island, and two others, Christmas Shearwater and Red-footed Booby, that visit but no longer nest. It is hypothesized that the Polynesian settlers may have driven these bird species, along with six terrestrial snail species, to local extinction, and this loss of a ready and regular food supply may have contributed to the Polynesians' subsequent disappearance.

Other animals

The invertebrate species are largely unknown but a third of the known snails and insects are endemic. There are no native mammals but the Pacific rat, introduced by Polynesians 800 years ago, abounds. A skink (Emoia cyanura), and the green sea turtle have been identified, and an unidentified gecko has been reported.

Biological risk

Land bird populations appear to be relatively stable but there is high risk of introduction to the island of predators, disease vectors and diseases by unauthorised landings of yachts. Introduction of the Eurasian black rat or the domestic cat would be likely to cause almost immediate extinction of the ground dwelling Henderson Crake and possibly other species. The endemic birds may have no immunity to the fatal avian pox which is transmitted by biting flies such as hippoboscidae.

Between July and November 2011 a partnership of the Pitcairn Islands Government and the Royal Society for the Protection of Birds implemented a poison baiting program aimed at eradicating the Pacific rat. A subsequent expedition has demonstrated the persistence of a (greatly reduced) rat population, and growth in the size of some of the island's unique bird populations.

Further reading

• Jared Diamond, Collapse: How Societies Choose to Fail or Succeed (2005), ch. 3.
• Nathaniel Philbrick, In the Heart of the Sea: The Tragedy of the Whaleship Essex, Penguin Books 2001.
• Chase, Owen (1821). Narrative of the Most Extraordinary and Distressing Shipwreck of the Whale-Ship Essex. W. B. Gilley. No ISBN. New York.
• Nickerson, Thomas (1984). The Loss of the Ship "Essex" Sunk by a Whale and the Ordeal of the Crew in Open Boats. Nantucket Historical Society.

External links

• The Henderson Island Website
• Henderson Island – UNESCO
• Henderson Island – Travel Log
• Henderson Island Travel Guide