Juan Fernández Islands

This article is about the Chilean archipelago. For other uses, see Juan Fernández.

Juan Fernández Islands Archipiélago Juan Fernández
Special Territory and Commune
The town of San Juan Bautista, Robinson Crusoe Island
Flag Coat of arms Juan Fernández Islands
Coordinates:
Country	Chile
Region	Valparaíso
Province	Valparaíso
Discovered	22 November 1574
Colony status	1895
Commune created	21 September 1979
Special territory status	30 July 2007
Named for	Juan Fernández
Capital	San Juan Bautista
Government
• Type	Municipality
• Body	Municipal council
• Alcalde (Mayor)	Felipe Paredes Vergara (PH)
Area
• Total	99.6 km2 (38.5 sq mi)
Population (2012 Census)
• Total	900
• Density	9.0/km2 (23/sq mi)
• Urban	800
• Rural	100
Sex
• Men	536
• Women	364
Time zone	CLT (UTC-4)
• Summer (DST)	CLST (UTC-3)
Area code(s)	56
Currency	Peso (CLP)
Website	Juan Fernández Islands

The Juan Fernández Islands (Spanish: Archipiélago Juan Fernández) are a sparsely inhabited island group reliant on tourism and fishing in the South Pacific Ocean. Situated 670 km (362 nmi; 416 mi) off the coast of Chile, they are composed of three main volcanic islands: Robinson Crusoe, Alejandro Selkirk and Santa Clara.

The islands are primarily known for having been the home to the marooned sailor Alexander Selkirk for more than four years from 1704, which may have inspired Daniel Defoe's Robinson Crusoe. Most of the archipelago's present-day inhabitants reside on Robinson Crusoe Island, mainly in the capital, San Juan Bautista, at Cumberland Bay on the island's north coast.

The group of islands are part of Chile's Valparaíso Region (which also includes Easter Island), and along with the Desventuradas Islands, form one of the nine communes of Valparaíso Province named Juan Fernández.

Geography

Landsat 7 image of the Juan Fernández Islands on 15 September 1999, shows the unique pattern of clouds known as a "Kármán vortex street" caused by the interaction of winds with the islands' mountains

• Robinson Crusoe Island (), also known as Isla Más a Tierra, is located closest to the mainland of continental South America, and is surrounded by a number of islets, including
  • Juanango and
  • Santa Clara (), lying 1 km (1 mi) southwest of Robinson Crusoe.
• Alejandro Selkirk Island (), also known as Más Afuera, is located 180 km (112 mi) further west.

Alejandro Selkirk is the largest of the Juan Fernández Islands at 49.5 km² (19 sq mi), and its highest peak, Los Innocentes, is 1,650 m (5,413 ft). The island's population was 57 in 2012. Robinson Crusoe is the second largest island in the archipelago at 47.9 km² (18 sq mi); its highest peak, El Yunque, is 915 m (3,002 ft). The population of Robinson Crusoe was 843 in 2012. Santa Clara is 2.2 km² (1 sq mi) in area, and reaches a height of 375 m (1,230 ft). Santa Clara is uninhabited. The maximum elevations of Juan Fernandez, 915 m (3,002 ft) for Robinson Crusoe and 1,650 m (5,410 ft) for Alejandro Selkirk, respectively, are high enough to cause the Kármán vortex street, which can be seen from space.

The islands are volcanic in origin, produced by the movement of the Nazca Plate over the Juan Fernández hotspot. As the plate moved eastward over the hot spot, volcanic eruptions formed the Juan Fernández Ridge before being subducted under the South American continent at the Peru–Chile Trench. The islands occur where the peaks of the submarine ridge have protruded above sea level. 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 Alexander Selkirk, 1.0 – 2.4 million years old.

Climate

The islands have a subtropical Mediterranean climate, moderated by the cold Humboldt Current, which flows northward to the east of the islands, and the southeast trade winds. Temperatures range from 3 °C (37 °F) to 34 °C (93 °F), with an annual mean of 15.4 °C (60 °F). Higher elevations are generally cooler, with occasional frosts on Robinson Crusoe.

Average annual precipitation is 1,081 mm (42.6 in), varying from 318 mm (12.5 in) to 1,698 mm (66.9 in) year to year. Much of the variability in rainfall depends on the El Niño-Southern Oscillation. Rainfall is higher in the winter months, and varies with elevation and exposure; elevations above 500 m (1,640 ft) experience almost daily rainfall, while the western, leeward side of Robinson Crusoe and Santa Clara are quite dry.

Climate data for Juan Fernández Islands
Month	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year
Average high °C (°F)	21.8 (71.2)	22.1 (71.8)	21.4 (70.5)	19.7 (67.5)	17.9 (64.2)	16.1 (61)	15.2 (59.4)	14.8 (58.6)	15.3 (59.5)	16.2 (61.2)	18.0 (64.4)	20.1 (68.2)	18.2 (64.8)
Daily mean °C (°F)	18.5 (65.3)	18.9 (66)	18.3 (64.9)	16.6 (61.9)	15.0 (59)	13.3 (55.9)	12.6 (54.7)	12.0 (53.6)	12.4 (54.3)	13.2 (55.8)	14.9 (58.8)	16.7 (62.1)	15.2 (59.4)
Average low °C (°F)	15.2 (59.4)	15.7 (60.3)	15.1 (59.2)	13.4 (56.1)	12.1 (53.8)	10.5 (50.9)	9.9 (49.8)	9.2 (48.6)	9.4 (48.9)	10.1 (50.2)	11.7 (53.1)	13.3 (55.9)	12.1 (53.8)
Average precipitation mm (inches)	24 (0.94)	38 (1.5)	38 (1.5)	78 (3.07)	143 (5.63)	160 (6.3)	161 (6.34)	115 (4.53)	72 (2.83)	55 (2.17)	28 (1.1)	24 (0.94)	936 (36.85)
Average precipitation days (≥ 0.1 mm)	11	10	13	15	21	23	21	19	16	14	10	10	183
Average relative humidity (%)	73	73	73	77	78	78	79	77	77	76	74	73	76
Mean monthly sunshine hours	248.0	209.1	158.1	123.0	108.5	99.0	93.0	105.4	147.0	204.6	249.0	260.4	2,005.1
Source #1: Sistema de Clasificación Bioclimática Mundial
Source #2: Climate and Temperature (humidity and sun)

Biota and ecology

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 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.

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. There are 126 species (62 percent) 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.

Alejandro Selkirk is mostly covered with grassland from 0 to 400 m (1,300 ft), interspersed with wooded ravines (quebradas), home to dry forests of Myrceugenia and Zanthoxylum fagara. From 400 m (1,300 ft) to 600 m (2,000 ft) are lower montane forests, with upper montane forest from 600 m (2,000 ft) to 950 m (3,100 ft). The treeline is at approximately 950 m (3,100 ft), 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 m (300 ft); introduced shrubs from 100 m (300 ft) to 300 m (1,000 ft); tall forests from 300 m (1,000 ft) to 500 m (1,600 ft); montane forests from 500 m (1,640 ft) to 700 m (2,300 ft), with dense tree cover of Cuminia fernandezia, Fagara, and Rhaphithamnus venustus; tree fern forests from 700 m (2,300 ft) to 750 m (2,500 ft), and brushwood forests above 750 m (2,500 ft). 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.

• Maps and satellite images of the islands
• 

  Map of Robinson Crusoe Island (including Santa Clara Island)

• 

  Map of Alejandro Selkirk Island

• 

  Map of both islands

• 

  Satellite images of Juan Fernández Islands (Alejandro Selkirk Island, inset left)

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. Introduced fauna by humans include rats and goats. Robinson Crusoe Island is home to an endemic and endangered hummingbird, the Juan Fernández firecrown (Sephanoides fernandensis). This large hummingbird, about 11 cm (4 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. The islands support the entire known breeding populations of two petrel species, Stejneger's Petrel Pterodroma longirostris (IUCN status VU) and the Juan Fernandez Petrel Pterodroma externa (IUCN status VU). In addition, the Juan Fernandez Islands may still support a third breeding petrel species, De Filippi's Petrel Pterodroma defilippiana (IUCN status VU), whose only other known breeding grounds are on the Desventuradas Islands.

The Magellanic penguin breeds on Robinson Crusoe Island within the archipelago. The endemic Juan-Fernandez spiny lobster (without claws) lives in the marine waters (Jasus frontalis). The Juan Fernández fur seal (Arctocephalus philippii) also 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 found about 750 fur seals living there. Only two were sighted on the Desventuradas Islands, located some 780 km (485 mi) to the north. 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 16–17 percent.

History

Robinson Crusoe Island, as seen in the late 19th or early 20th century. The ship in Cumberland Bay is the cruiser Esmeralda

The archipelago was discovered on 22 November 1574, by the Spanish sailor Juan Fernández, who was sailing south between Callao and Valparaíso along a route which he also discovered, hundreds of miles west of the coast of Chile, which avoided the northernly Humboldt current. He called the islands Más Afuera, Más a Tierra, and Santa Clara.

In the 17th and 18th centuries, the islands were used as a hideout for pirates, were the site of Alexander Selkirk's four-year marooning, and provided a location for a penal colony. In the 1740s, they were 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.

During the maritime fur trade era of the early 19th century the islands were a source of fur seal skins, and the Juan Fernández fur seal was nearly driven to extinction. In his book, Two Years Before the Mast (Chapter VII), Richard Henry Dana, Jr. described the islands as he found them circa 1834. At this time the main island was being used as a penal colony. However, when Dr John Coulter visited the penal colony in the early 1840s, he reported it deserted after the convicts had risen up and killed the soldiers who had held them captive. The prisoners fled to mainland Chile, where they were later hunted down and shot. The story appears in Coulter's book Adventures in the Pacific (1845). 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.

SMS Dresden, shortly before its scuttling in Cumberland Bay

Late in 1914 the islands were the rendezvous for Admiral Maximilian von Spee's East Asiatic Squadron as he gathered his ships together before 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 hunted down and cornered at Más a Tierra early in 1915, where it was scuttled after a brief battle with British cruisers.

In 1966 the Chilean government renamed Más Afuera as Alejandro Selkirk Island and Más a Tierra as Robinson Crusoe Island, in order to promote tourism. Incidentally, Selkirk never set foot on Más Afuera, only on Más a Tierra. On 30 July 2007, a constitutional reform gave the Juan Fernández Islands and Easter Island the status of "special territories" of Chile. Pending the enactment of a charter the archipelago will continue to be governed as a commune of the Valparaíso Region.

On 27 February 2010, a tsunami following the 8.8 magnitude earthquake off Maule, Chile struck the islands causing at least 8 deaths. Eleven people were reported as missing. Some early reports described the tsunami wave as being 40 m (130 ft) high, but later reports measured it at 3 m (10 ft). Most of the town of San Juan Bautista on Robinson Crusoe Island was destroyed.

Government

As a commune, the Juan Fernández Islands are a third-level administrative division of Chile governed by a municipal council, headed by a mayor (Spanish: alcalde) who is directly elected every four years. The mayor for the term 2012–2016 was Felipe Paredes Vergara.

Within the electoral divisions of Chile, the commune was represented in the Chamber of Deputies by Joaquín Godoy (RN) and Aldo Cornejo (PDC) as part of the 13th electoral district (together with Valparaíso and Easter Island). It was represented in the Senate by Francisco Chahuán Chahuán (RN) and Ricardo Lagos Weber (PPD) as part of the 6th senatorial constituency (Valparaíso-Coast).

Demographics

According to data from the 2012 Census of Population and Housing, the commune of Juan Fernández had 900 inhabitants; of these, 800 (88.9 percent) lived in urban areas and 100 (11.1 percent) in rural areas. At that time there were 536 men and 364 women. Most of the population is of European origin, mainly Spanish, British, German and other European nationalities.

See also

• Endemic fauna of the Juan Fernández Islands
• Endemic flora of the Juan Fernández Islands
• Flora of the Juan Fernández Islands

External links

• Commune Juan Fernández official government website (in Spanish)
• "Images of the Juan Fernández Islands" by W. Schipper in Travel Images
• "Map of Chili" by S. Augustus Mitchell (1860) from the World Digital Library
• "Menaces et perspectives pour la préservation de la biodiversité de l'Archipel Juan Fernández (Chili)" by J. Vanhulst (2009) on preserving the islands' biodiversity (in French)