Sumatra (also spelled Sumatera) is the sixth largest island of the world (approximately 470,000 km?) and is the largest island entirely in Indonesia (two larger islands, Borneo and New Guinea, are partially in Indonesia).

An ancient name for Sumatra was Swarna Dwipa, (Sanskrit for Isle of Gold), apparently based on the fact that mines in the Sumatran highlands were exporting gold from fairly early times.

The longest axis of the island runs approximately northwest - southeast, crossing the equator near the center. The interior of the island is dominated by two geographical regions: the Barisan Mountains in the west and swampy plains in the east.

To the southeast is Java, separated by the Sunda Strait. To the north is the Malay Peninsula, separated by the Straits of Malacca. To the east is Borneo, across the Karimata Strait. West of the island is the Indian Ocean.

The backbone of the island is the Barisan mountains chain. The volcanic activity of this region endowed the region with fertile land and beautiful sceneries, for instance around the Lake Toba. It also contains deposits of coal and gold.

To the east, big rivers carry silt from the mountain, forming the vast lowland interspersed by swamps. Even if mostly unsuitable for farming, the area is currently of great economic importance for Indonesia. It produces oil from both above and below the soil?palm oil and petroleum.

Most of Sumatra used to be covered by tropical rainforest, but economic development coupled with corruption and illegal logging has severely threatened its existence. Conservation areas have not been spared from destruction, either.

The island is the world's 8th highest island, although only the third highest in the Indonesian archipelago.

Demographics

Sumatra is not very densely populated, about 85 people per km??more than 40 million people in total. It is nonetheless the fourth most populous island in the world. The most populous regions includes most of North Sumatra and central highlands in West Sumatra, while the major urban centres are Medan and Palembang.

The people are of Malay stock composed of many different tribes, speaking 52 different languages. Most of these groups, however, share many similar traditions and the different tongues are closely related. Malay-speaking people dominate the eastern coast, while people in the southern and central interior speak languages related to Malay, such as the Lampung and Minangkabau people. The highland of northern Sumatra is inhabited by the Bataks, while the northernmost coast is dominated by Acehs. Ethnic Chinese minorities are also present in urban centers.

A majority of people in Sumatra are Muslims (90%). Most central Bataks, meanwhile, are Protestant Christians?a religion introduced by the Dutch. The rest follow Hinduism, Buddhism, Catholicism, and Chinese traditional beliefs.

Flora and fauna

The island is home to a host of species including: Sumatran Pine, Rafflesia arnoldii (world's largest flower), Titan arum (world's tallest flower), Sumatran Tiger, Orangutan, Sumatran Rhinoceros, Sumatran Elephant, Malayan Tapir, Malayan Sun Bear, Clouded Leopard, and many birds and butterflies.

The major threats to Sumatran forest are the pulp and paper industry and expansion of palm oil plantations.

The island includes more than 10 National Parks, including 3 which are listed as the Tropical Rainforest Heritage of Sumatra World Heritage Site?Gunung Leuser National Park, Kerinci Seblat National Park and Bukit Barisan Selatan National Park.

Orangutan

The orangutans are two species of great apes with long arms and reddish, sometimes brown, hair native to Indonesia and Malaysia . They are the only extant species in the genus Pongo and the subfamily Ponginae, although that subfamily also includes the extinct Gigantopithecus and Sivapithecus genera. The orangutan is an official state animal of Sabah in Malaysia. Their name derives from the Malay and Indonesian phrase orang hutan meaning "person of the forest".

Orangutans are the most arboreal of the great apes, spending nearly all of their time in the trees, making a new nest in the trees every night. Adult males are about 4.5 ft (1.4 m) tall and up to 180 lb (82 kg) in weight. They are only found in rainforests on the islands of Borneo and Sumatra.

Conservation

The Borneo species of orangutans are highly endangered and the Sumatran species is critically endangered according to the IUCN Red List of Mammals and both are listed on Appendix I of CITES. The Borneo population is about 50,000 in the wild, while the Sumatran species is 7,000 to 7500 individuals. Orangutan habitat destruction due to logging, mining and forest fires has been increasing rapidly in the last decade. Much of this activity is illegal, occurring in national parks that are officially off limits to loggers, miners and plantation development. There is also a major problem with the illegal trapping of baby orangutans for sale into the pet trade; the trappers usually kill the mother to steal the baby. Major conservation centres in Indonesia include those at Tanjung Puting in Central Kalimantan, Kutai in East Kalimantan, Gunung Palung in West Kalimantan, and Gunung Leuser in Aceh and North Sumatera. In Malaysia, conservation areas include Semenggok in Sarawak, and Sepilok near Sandakan in Sabah.