Difference between revisions of "Juan Fernández Islands" - New World Encyclopedia

From New World Encyclopedia
Line 161: Line 161:
 
[[Species]] that have been introduced to the islands threaten the naturally occurring species. Introduced [[animal]]s include [[goat]]s and [[rabbit]]s, who have increased [[erosion]] throughout the landscape. Wild [[cat]]s hunt endemic [[bird]] species, and have drastically reduced their numbers. Invasive [[plant]]s, numbering 195 known groups, have displaced local plant life. [[Habitat]] loss is occurring through the lumbering of [[forest]]s. Invasive species coupled with habitat loss have caused the extinction of several plant species, and at least three-quarters of the remaining native plants are threatened or endangered.<ref name=wwf>''World Wildlife Fund''. [http://www.worldwildlife.org/wildworld/profiles/terrestrial/nt/nt0401_full.html Juan Fernández Islands temperate forests] Retrieved February 18, 2009.</ref>
 
[[Species]] that have been introduced to the islands threaten the naturally occurring species. Introduced [[animal]]s include [[goat]]s and [[rabbit]]s, who have increased [[erosion]] throughout the landscape. Wild [[cat]]s hunt endemic [[bird]] species, and have drastically reduced their numbers. Invasive [[plant]]s, numbering 195 known groups, have displaced local plant life. [[Habitat]] loss is occurring through the lumbering of [[forest]]s. Invasive species coupled with habitat loss have caused the extinction of several plant species, and at least three-quarters of the remaining native plants are threatened or endangered.<ref name=wwf>''World Wildlife Fund''. [http://www.worldwildlife.org/wildworld/profiles/terrestrial/nt/nt0401_full.html Juan Fernández Islands temperate forests] Retrieved February 18, 2009.</ref>
  
The plight of the archipelago's endangered natural systems has been recognized. The International Union for the Conservation of Nature and Natural Resources (IUCN) identified the Juan Fernández Islands as one of the world's 12 most threatened [[national park]]s, and in 1984 the International Council for Bird Preservation (ICBP) designated the islands as one of the 10 highest priority regions for [[seabird]] research globally. In 1998, BirdLife International listed the islands as a Priority 1 (critical) Endemic Bird Area of the World. The Alliance for Zero Extinction (AZE) targeted the Juan Fernández Islands as a priority site in 2002, an area in most urgent need of conservation investment to prevent imminent species extinctions.<ref>''Oikonos''. August 2008. [http://www.oikonos.org/projects/jfic.htm Juan Fernandez Islands Conservancy] Retrieved February 19, 2009.</ref>
+
The plight of the archipelago's endangered natural systems has been recognized. The [[International Union for the Conservation of Nature and Natural Resources]] (IUCN) identified the Juan Fernández Islands as one of the world's 12 most threatened [[national park]]s, and in 1984 the International Council for Bird Preservation (ICBP) designated the islands as one of the 10 highest priority regions for [[seabird]] research globally. In 1998, BirdLife International listed the islands as a Priority 1 (critical) Endemic Bird Area of the World. The Alliance for Zero Extinction (AZE) targeted the Juan Fernández Islands as a priority site in 2002, an area in most urgent need of conservation investment to prevent imminent species extinctions.<ref>''Oikonos''. August 2008. [http://www.oikonos.org/projects/jfic.htm Juan Fernandez Islands Conservancy] Retrieved February 19, 2009.</ref>
  
 
Since the 1990s the Chilean Government, along with several international organizations, has been involved in projects to educate the local populations on conservation for the native [[ecosystems]]. However, the restoration work has not proven sufficient to stall the effects of many aggressive introduced species.<ref name=wwf/>
 
Since the 1990s the Chilean Government, along with several international organizations, has been involved in projects to educate the local populations on conservation for the native [[ecosystems]]. However, the restoration work has not proven sufficient to stall the effects of many aggressive introduced species.<ref name=wwf/>

Revision as of 03:33, 19 February 2009

Coordinates: 33°S 80°W / -33, -80

Islas de Juan Fernández
Juan Fernández Islands
Flag of Juan Fernández Islands
Location of Juan Fernández Islands
Map of Insular Chile with Easter Island, Sala y Gómez, Desventuradas Islands and Juan Fernández Islands
CapitalSan Juan Bautista
33°38′S 78°51′W / -33.633, -78.85
Official languages Spanish
Government Special territory of Chile
Area
 -  Total 181 km² 
113 sq mi 
Population
 -  2002 census 598 
 -  Density 3.3/km² 
5.3/sq mi
Currency Peso (CLP)
Time zone n/a (UTC-4)
 -  Summer (DST) n/a (UTC-3)
Internet TLD .cl
Calling code +56

The Juan Fernández Islands is a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean. The archipelago is situated about 667 kilometers (414 mi) off the coast of Chile, and is composed of several volcanic islands and islets: Robinson Crusoe Island, Alejandro Selkirk Island, Santa Clara, and Juananga.

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 181 km², of which 93 km² are taken up by Robinson Crusoe (together with Santa Clara), and 33 km² by Alejandro 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 Valparaíso (which also includes Easter Island), and more specifically forms one of the nine comunas (municipalities) of the province of Valparaíso, namely Juan Fernández.

As World Biosphere Reserves since 1977, these islands have been considered of maximum scientific importance because of the endemic species of flora and fauna (101 of the 146 native species of plants are endemic.) The Magellanic Penguin is found at Robinson Crusoe Island. The Juan Fernández Firecrown is an endemic and critically endangered red hummingbird and is most famous for its needle-fine black beak and silken feather coverage.


"The Juan Fernández Islands have received national and international recognition for their biological uniqueness - designated a Chilean National Park in 1935 and an UNESCO International Biosphere Reserve in 1977 and nominated for World Heritage status in 1995. Over 60% of the native plants are endemic to the archipelago, including 12 endemic genera and one endemic family (Lactoridaceae). Thirty-five of the 46 mollusks and more than 440 of the 660+ species of invertebrates are also endemic. There are no native amphibians or reptiles, and the only native mammal is the endemic Juan Fernández fur seal (Arctocephalus philippii). The Juan Fernández Islands are home to nine native terrestrial bird species, of which three are endemic species and an additional three are endemic subspecies (1 and 2). Six species of seabirds breed on the islands, of which two are endemic to the islands, and another two are endemic to Chile."


Islands of the archipelago

Three main islands make up the Juan Fernández Islands chain: Mas a Tierra (or Robinson Crusoe), Mas Afuera (or Alejandro Selkirk), and Santa Clara.

  • Robinson Crusoe (also known as Isla Más a Tierra), located nearest the mainland of continental South America, and its surrounding islets including Juananga (Islote Juananga)
  • Santa Clara (Isla Santa Clara)
  • Alejandro Selkirk Island (also known as Isla Más Afuera), 181 km (112 mi) west of Robinson Crusoe Island.
The town of San Juan Bautista in Cumberland Bay, Robinson Crusoe Island
A fisherman with two spiny lobsters off Robinson Crusoe Island

Robinson Crusoe Island is the largest of the islands. It has a mountainous and undulating terrain, formed by ancient lava flows which have built up from numerous volcanic episodes. The highest point on the island is 916 metres (3,010 ft) above sea level at El Yunque. Intense erosion has resulted in the formation of steep valleys and ridges. A narrow peninsula is formed in the southwestern part of the island called Cordon Escarpado. The island of Santa Clara is 1.5 km from the coast off the southern part of the island. The western end of the island is the lowest and driest area on the island.

There is a population between 500-600 living in the village of San Juan Bautista. The community maintains a rustic serenity dependent on the spiny lobster trade. The island welcomes several hundred tourists per, with scuba diving gaining in popularity.

Alejandro Selkirk Island is the second largest and most westerly island of the group. It is densely wooded and very mountainous. It is marked by ridges and numerous deep ravines lead to a rugged eastern coast off which are tremendous depths. The coastal cliffs are up to 1,000 meters high. The south, west and north sides of the island have sandy strips of beach which extend 0.1 mile offshore in places. The highest peak, Cerro de Los Inocentes, rises to 1,329 metres (4,360 ft) at the of the southwest side of the island.

About 59 km (37 mi) southwest of the island is submerged Sefton Reef, nearly reaching sea level, and 47 km (29 mi) northwest is Yosemite Rock. Podesta Island reported further west is a phantom island.

The island once housed a penal settlement on its central east coast, which was operative from 1909 to 1930. It initially housed 190 criminals. From 1927 to 1930, there were 160 political prisoners on the island.[1] About 20 buildings remain.

Santa Clara is the smallest of the mainland islands in the group. It is located 1.5 km (0.93 mi) from the south coast of Robinson Crusoe Island. The island is 375 metres (1,230 ft) high and the terrain is dry. The majority of the original vegetation on the island has been replaced by shrubs and grasses.

Geology

The Juan Fernández Islands are volcanic in origin, and were created by a hotspot in the earth's mantle that broke through the Nazca Plate to form the islands, which were then carried eastward off the hot spot as the Nazca Plate subducted 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, 3.8-4.2 million years old, and Alejandro Selkirk, 1.0-2.4 million years old. Robinson Crusoe is the largest of the islands, at 93 km² and the highest peak, El Yunque, is 916 meters. Alejandro Selkirk is 50 km²; its highest peak is Los Inocentes at 1319 meters. Santa Clara is 2.2 km², and reaches 350 meters.

Climate

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 3-34 °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 Niño-Southern Oscillation.

Ecology

Orthographic projection centered over Juan Fernandez Islands
Map of Isla Más a Tierra / Crusoe
Map of Isla Más Afuera / Selkirk

The Juan Fernández 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 necessitated the islands' flora and fauna reaching the archipelago from far across the sea; as a result, the island has relatively few plants and very few animals. 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.

Flora

There are 209 native species of vascular plants in the Juan Fernandez Islands, approximately 150 of which are flowering plants, and 50 are ferns. 126 species, or 62 percent, 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.

Alejandro Selkirk Island is mostly covered with grassland from 0-400 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 Island, grasslands predominate from 0-100 meters; introduced shrubs from 100-300 meters; tall forests from 300-500 meters; montane forests from 500-700 meters, with dense tree cover of Cuminia, Fagara, and Rhaphithamnus; tree fern forests from 700-750 meters, and brushwood forests above 750 meters. Santa Clara Island 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 Alejandro Selkirk. Endemic tree fern species of southern hemisphere genus Dicksonia (D. berteriana on Robinson Crusoe and D. externa on Alejandro 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.

Fauna

The Juan Fernández 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 Fernández Firecrown (Sephanoides fernandensis). This large hummingbird, about 11 cm (5 in) long, is thought to number only about 500 individuals. The other endemic bird species are the Juan Fernández 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.

The Magellanic Penguin breeds at Robinson Crusoe Island.[2] The endemic Juan-Fernandez spiny lobster (without claws) lives in the marine waters (Jasus frontalis).

The Juan Fernández Fur Seal is known to have existed during the late-1600s on the island with the population of the seals on Alejandro Selkirk Island and Robinson Crusoe Island believed to be in excess of four million by the late 17th century. A census of 1797 estimated a population 2-3 million fur seals.[3] The species was hunted to near extinction by the 1800s and was thought to be extinct for 100 years until 200 were found on the island in 1965. Since then, the population has grown at a steady rate of 15-20 percent every year.[4]

History

The archipelago was discovered by chance on November 22, 1574, by the Spanish sailor Juan Fernández, who was sailing between Peru and Valparaíso and deviated from his planned course. He called the islands Más Afuera, Más 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.

An 1835 book inspired by Selkirk's life

Alexander Selkirk, a Scottish sailor, joined in with the expedition of privateer and explorer William Dampier in 1703. Dampier was captain of the St. George, and Selkirk served on the companion galleon Cinque Ports, as a sailing master under Thomas Stradling. In October 1704, after the ships had parted ways because of a dispute between Stradling and Dampier, the Cinque Ports was brought by Stradling to the uninhabited archipelago of Juan Fernández for a mid-expedition restocking of supplies and fresh water. Selkirk, who had grave concerns about the seaworthiness of the vessel tried to convince some of his crewmates to desert with him, and remain on the island. He believed they could survive several months until another ship came for restocking. A disagreement arose between Stradling and Selkirk, and the latter was left alone on the island. It was not until February 2, 1709 - more than four years later - that Selkirk was rescued. It is generally accepted that Selkirk's adventures as a castaway were the inspiration for Daniel Defoe's masterpiece "Robinson Crusoe".

The location of the archipelago was fixed by Alessandro Malaspina in 1790. Previous charts had differed on the location.[5]

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 Más a Tierra early in 1915, where she was scuttled after a brief battle with British cruisers.

In 1966 the Chilean government renamed Isla Más Afuera to Alejandro Selkirk Island and Isla Más a Tierra to Robinson Crusoe Island, in order to promote tourism. Incidentally, Selkirk never set foot on Más Afuera, only on Más a Tierra.

In July 30 2007, a constitutional reform gave the Juan Fernández Islands and Easter Island the status of special territories of Chile. The archipelago will continue to be governed as a municipality of the Valparaíso Region.[6]

Concerns

Species that have been introduced to the islands threaten the naturally occurring species. Introduced animals include goats and rabbits, who have increased erosion throughout the landscape. Wild cats hunt endemic bird species, and have drastically reduced their numbers. Invasive plants, numbering 195 known groups, have displaced local plant life. Habitat loss is occurring through the lumbering of forests. Invasive species coupled with habitat loss have caused the extinction of several plant species, and at least three-quarters of the remaining native plants are threatened or endangered.[7]

The plight of the archipelago's endangered natural systems has been recognized. The International Union for the Conservation of Nature and Natural Resources (IUCN) identified the Juan Fernández Islands as one of the world's 12 most threatened national parks, and in 1984 the International Council for Bird Preservation (ICBP) designated the islands as one of the 10 highest priority regions for seabird research globally. In 1998, BirdLife International listed the islands as a Priority 1 (critical) Endemic Bird Area of the World. The Alliance for Zero Extinction (AZE) targeted the Juan Fernández Islands as a priority site in 2002, an area in most urgent need of conservation investment to prevent imminent species extinctions.[8]

Since the 1990s the Chilean Government, along with several international organizations, has been involved in projects to educate the local populations on conservation for the native ecosystems. However, the restoration work has not proven sufficient to stall the effects of many aggressive introduced species.[7]

Notes

  1. Maura Brescia. 2004. Selkirk Robinson, el mito: a tres siglos del desembarco del solitario en Isla Robinson Crusoe. Santiago, Chile: Editorial Mare Nostrum. (ISBN 9568089047) p 245 (Spanish)
  2. C. Michael Hogan. 2008. Magellanic Penguin GlobalTwitcher.com. ed. N. Stromberg. Retrieved February 18, 2009.
  3. Ronald M. Nowak. 1999. Walker's mammals of the world. Baltimore: Johns Hopkins University Press. (ISBN 0801857899) p 846
  4. A. Rus Hoelzel. 2002. Marine Mammal Biology: An Evolutionary Approach. Oxford: Blackwell Science. (ISBN 0632052325) p330
  5. John Kendrick. 2003. Alejandro Malaspina portrait of a visionary. Montreal: McGill-Queen's University Press. (ISBN 0773526528) Online preview
  6. National Congress of Chile. Chilean Law 20,193 Retrieved February 18, 2009. (Spanish)
  7. 7.0 7.1 World Wildlife Fund. Juan Fernández Islands temperate forests Retrieved February 18, 2009.
  8. Oikonos. August 2008. Juan Fernandez Islands Conservancy Retrieved February 19, 2009.

References
ISBN links support NWE through referral fees

External links

All Links Retrieved February 18, 2009.

Credits

New World Encyclopedia writers and editors rewrote and completed the Wikipedia article in accordance with New World Encyclopedia standards. This article abides by terms of the Creative Commons CC-by-sa 3.0 License (CC-by-sa), which may be used and disseminated with proper attribution. Credit is due under the terms of this license that can reference both the New World Encyclopedia contributors and the selfless volunteer contributors of the Wikimedia Foundation. To cite this article click here for a list of acceptable citing formats.The history of earlier contributions by wikipedians is accessible to researchers here:

The history of this article since it was imported to New World Encyclopedia:

Note: Some restrictions may apply to use of individual images which are separately licensed.