Juan Fernandez Islands
The Juan Fernandez Islands are a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean, situated about off the coast of Chile, and is composed of several volcanic islands:
Robinson Crusoe, (also known as Isla Mas a Tierra), located closest to the mainland of continental South America, and its surrounding islets:
* Juananga, (Islote Juananga)
* Santa Clara (Isla Santa Clara), an islet located southwest of Robinson Crusoe
Alejandro Selkirk Island (also known as Isla Mas Afuera), further west.
The islands are mainly known for having been the home to the sailor Alexander Selkirk for four years, which may have inspired the novel Robinson Crusoe. The islands have an area of , of which are taken up by Robinson Crusoe (together with Santa Clara), and by Alexander Selkirk. The population is 633 (all on Robinson Crusoe); of those 598 reside in the capital, San Juan Bautista, on Cumberland Bay on the north coast of the island (2002 census).
The archipelago administratively belongs to Chile's Region of Valparaiso (which also includes Easter Island), and more specifically forms one of the nine comunas (municipalities) of the province of Valparaiso, namely Juan Fernandez.
In the aftermath of the earthquake that occurred off the Chilean coast on 27 February 2010, there were reports of damage and loss of life from a tsunami that hit the island. This led to the deaths of five people, with eleven people reported as missing. Some early reports described the tsunami wave as being 40 metres high, but later reports claimed it was 3 m (10 ft).
The archipelago was discovered by chance on November 22, 1574, by the Spanish sailor Juan Fernandez, who was sailing between Peru and Valparaiso and deviated from his planned course. He called the islands Mas Afuera, Mas a Tierra, and Islote de Santa Clara.
In the 17th and 18th century it was used as a hideout for pirates, and provided a location for a penal colony. In the 1740s, it was visited by Commodore Anson's flotilla during his ill-fated venture to the South Seas.
The location of the archipelago was fixed by Alessandro Malaspina in 1790. Previous charts had differed on the location.
In 1908 the islands were visited by the Swedish Magellanic Expedition and Carl Skottsberg is believed to have been the last to have seen the Santalum fernandezianum tree alive.
In late 1914 the islands were the rendezvous for Admiral Maximilian von Spee's East Asiatic Squadron as he gathered his ships together prior to defeating the British under Admiral Christopher Cradock at the Battle of Coronel.
Following the Royal Navy's revenge at the Battle of the Falkland Islands a month later, the only surviving German cruiser, SMS Dresden, was finally hunted down and cornered at Mas a Tierra early in 1915, where she was scuttled after a brief battle with British cruisers.
In 1966 the Chilean government renamed Isla Mas Afuera to Alejandro Selkirk and Isla Mas a Tierra to Robinson Crusoe, in order to promote tourism. Incidentally, Selkirk never set foot on Mas Afuera, only on Mas a Tierra.
In July 30, 2007, a constitutional reform gave the Juan Fernandez Islands and Easter Island the status of special territories of Chile. Pending the enactment of a special charter, the archipelago will continue to be governed as a municipality of the Valparaiso Region.
On 27 February 2010, a tsunami caused by the 8.8 magnitude earthquake off Maule, struck the islands, causing at least 8 deaths. This was the first report of a tsunami relayed to the central government in Santiago. Time Magazine, "Chile's President: Why Did Tsunami Warnings Fail?", Eben Harrell, 2 March 2010 (accessed 4 March 2010)
As to the population of the island, most is of European origin, mainly Spanish, British, Germans and other European nationalities.
The islands are volcanic in origin, and were created by the Juan Fernandez hotspot that penetrates the Earth's mantle breaking through the Nazca Plate to form the islands. The islands have then been carried eastward off the hot spot forming the Juan Fernandez Ridge as the Nazca Plate subducts under the South American continent. Radiometric dating indicates that Santa Clara is the oldest of the islands, 5.8 million years old, followed by Robinson Crusoe, 3.84.2 million years old, and Alexander Selkirk, 1.02.4 million years old. Robinson Crusoe is the largest of the islands, at and the highest peak, El Yunque, is . Alexander Selkirk is ; its highest peak is Los Innocentes at . Santa Clara is , and reaches a height of .
The islands have a subtropical climate, influenced by the cold Humboldt Current which flows northward along the South American coast east of the islands, and the southeast trade winds. The temperature ranges from 3 to 34 C, with an annual mean of 15.4 C. Higher elevations are generally cooler, with occasional frosts on Robinson Crusoe. Rainfall is higher in the winter months, and varies with elevation and exposure; elevations above 500 meters experience almost daily rainfall, while the western, leeward side of Robinson Crusoe and Santa Clara are quite dry. Average annual rainfall is 1081 mm, varying from 318 to 1698 mm year to year. Much of the variability in rainfall depends on the El Nino-Southern Oscillation.
The Juan Fernandez islands are home to a high percentage of rare and endemic plants and animals, and are recognized as a distinct ecoregion. The volcanic origin and remote location of the islands meant that the islands' flora and fauna had to reach the archipelago from far across the sea; as a result, the island is home to relatively few plant species and very few animal species. The closest relatives of the archipelago's plants and animals are found in the Temperate broadleaf and mixed forests ecoregions of southern South America, including the Valdivian temperate rain forests, Magellanic subpolar forests, and Desventuradas Islands.
There are 209 native species of vascular plants in the Juan Fernandez Islands, approximately 150 of which are flowering plants, and 50 are ferns. There are 126 species (62%) that are endemic, with 12 endemic genera and one endemic family, Lactoridaceae. Many plants are characteristic of the Antarctic flora, and are related to plants found in southern South America, New Zealand and Australia.
Vegetation zones generally correspond to elevation, with grasslands and shrublands at lower elevations, tall and montane forests at middle elevations, and shrublands at the highest elevations. The two main islands have somewhat distinct plant communities.
Alexander Selkirk is mostly covered with grassland from 0 to 400 meters, interspersed with wooded ravines (quebradas), home to dry forests of Myrceugenia and Fagara. From 400 to 600 meters are lower montane forests, with upper montane forest from 600 to 950 meters. The treeline is at approximately 950 meters, above which is alpine shrubland and grassland, dominated by temperate Magellanic vegetation such as Acaena, Dicksonia, Drimys, Empetrum, Gunnera, Myrteola, Pernettya, and Ugni.
On Robinson Crusoe, grasslands predominate from 0 to 100 meters; introduced shrubs from 100 to 300 meters; tall forests from 300 to 500 meters; montane forests from 500 to 700 meters, with dense tree cover of Cuminia, Fagara, and Rhaphithamnus; tree fern forests from 700 to 750 meters, and brushwood forests above 750 meters. Santa Clara is covered with grassland.
Three endemic species dominate the tall and lower montane forests of the archipelago, Drimys confertifolia on both main islands, Myrceugenia fernandeziana on Robinson Crusoe, and M. schulzei on Alexander Selkirk. Endemic tree fern species of southern hemisphere genus Dicksonia (D. berteriana on Robinson Crusoe and D. externa on Alexander Selkirk) and the endemic genus Thyrsopteris (T. elegans) are the predominant species in the tree-fern forests. An endemic species of sandalwood, Santalum fernandezianum, was overexploited for its fragrant wood, has not been seen since 1908, and is believed extinct. The Chonta Palm (Juania australis) is endangered.
The Juan Fernandez Islands have a very limited fauna, with no native land mammals, reptiles, or amphibians. Seventeen land and sea-bird species breed on the islands. The island has three endemic bird species, and two endemic subspecies.
Robinson Crusoe Island is home to an endemic and endangered hummingbird, the Juan Fernandez Firecrown (Sephanoides fernandensis).
This large hummingbird, about long, is thought to number only about 500 individuals. The other endemic bird species are the Juan Fernandez Tit-tyrant (Anairetes fernandezianus) of Robinson Crusoe Island, and the Masafuera Rayadito (Aphrastura masafuerae) of Alejandro Selkirk Island.
Introduced fauna by humans include rats and goats, which castaway Alexander Selkirk survived on during his four year stay from 1705 to 1709; his travails provided the inspiration for Daniel Defoe's novel Robinson Crusoe.
The Magellanic Penguin breeds at Robinson Crusoe Island within this archepelago.C. Michael Hogan (2008) Magellanic Penguin, GlobalTwitcher.com, ed. N. StrombergThe endemic Juan-Fernandez spiny lobster (without claws) lives in the marine waters (Jasus frontalis).
The Juan Fernandez Fur Seal (Arctocephalus philippii) lives on the islands. This species was nearly exterminated in the sixteenth to nineteenth century, but it was rediscovered in 1965. A census in 1970 indicated about 750 fur seals present in the Archipelago. Only two were sighted on the Desventuradas Islands. The actual population of the Desventuradas may be higher, because the species tends to hide in sea caves. There seems to be a yearly population increase of 1617%.
Juan Fernandez Islands site
Human impact on vegetation of the Juan Fernandez Islands, Chile
Juan Fernandez Islands - images
Map of Robinson Crusoe Island
Juan Fernandez Islands temperate forests (World Wildlife Fund)
A digital field trip to Robinson Crusoe Island
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article Juan Fernandez Islands