By Jeremy Hance


Land Areas: 174,600 square kilometers, making it the world’s 11th largest island (67, 413 square miles, 17.4 million hectares, or 43 million acres)
Human Population: 16 million (2005)
Country: Indonesia
Biodiversity: 1450 birds, 127 mammals, 5,972 vascular plants (2,225 of which are endemic)
Percent Forest Cover: Around 20%
Deforestation Rate: 2.35 percent annually between 1985-1997)
Causes of Deforestation: Agriculture, logging, and mining


Shaped like a lower-case 'k', the Indonesian island of Sulawesi is the world’s eleventh largest island. A treasure-trove of biodiversity with a startling number of endemic species (species that are found no-where else in the world), Sulawesi—formerly known as Celebes—has only recently become a target of conservationists. While much of the island remains unstudied by researchers much of its forest habitat has already been lost.

The tropical forests—which once covered the whole island—have been broadly deforested by agriculture, logging, and mining. The process accelerated in the late 20th Century when the government began supporting commercial logging and large agriculture projects. Locals also began converting forests into cash crops.

A study in 2007 found that 80 percent of Sulawesi's forest is gone or degraded, including almost the entirety of Sulawesi’s rich lowland rainforest and mangroves. The study further speculated that little deforestation in the future is possible since most of forest land that was useful for cultivation and logging is already gone. With few attractive commercial trees, Sulawesi’s highland forests have fared better, though many have suffered from degradation.


At 174,600 square kilometers, Sulawesi is the world's eleventh largest island just after Ellesmere Island in Canada. It is famously described as a big island with no interior, given that the island consists almost entirely of four interconnecting peninsulas.

Its large and winding coastline measures 6,000 kilometers. The island is surrounded on all sides by other big islands: Borneo to the west, Philippines to the north, the Maluku islands to the east, and Flores and Timor to the south.

Politically, Sulawesi is split into six Indonesian provinces: Mamuju (West Sulawesi), Manado (North Sulawesi), Palu (Central Sulawesi), Makassar (South Sulawesi), Kendari (Southeast Sulawesi), and Gorontalo. With 1.25 million people, Makassar is the largest city on the island; it rests on the southwestern peninsula.

The strange shape of Sulawesi—five connected peninsulas with little to hold them together—was created by a collision of multiple plates originating from Asia, Australia, and the Pacific islands.

The island contains thirteen freshwater lakes including the deepest lake, Matano, in Southeast Asia.


Sulawesi is largely dependent on crops and seafood for its economy: in 2004 agriculture made up 34 percent of Sulawesi's economy. Crops important to Sulawesi's economy include coconuts, nutmeg, soy, coffee, and rice. The island is one of the world's largest producers of cacao. It also produces a lot of cloves for kretek cigarettes.

Fishing, and increasingly aquaculture, has become important to Sulawesi's economy. Fish ponds and shrimp aquaculture has replaced much of the island's mangroves.

Other economic industries include commercial timber such as teak and rattan and tourism, which is seen as increasingly important by the government.

In 2004, 16.7 percent of Sulawesi's population were considered to be living in poverty. Most of the poor live in rural areas.


Sulawesi has a remarkable diversity of terrestrial flora and fauna and rich coastal marine life. Since the unique island sits on Wallace's Line it harbors species of both Asian and Australasian ancestors, though the majority are Australasian in origin.

On land, the percentage of endemic species is particularly noteworthy. Of 127 known mammals, 72 are endemic, making for one of the highest rates of endemic mammals in the world (62 percent). When bats are excluded—since they have better potential for migration—the percentage leaps to an astounding 98 percent. In addition, 34 percent of Sulawesi’s nearly 1500 birds are endemic.

Other fauna are unfortunately little studied. Twenty-five species of amphibian are known, forty lizards, and at least 52 terrestrial snakes. In addition, there are 38 species of large swallow-tailed butterfly, which so entranced Alfred Russell Wallace on his visit to the island. Researchers have also found 67 endemic species of fish in Sulawesi's dwindling mangrove forests.

Some standouts include:

  • Two wild cattle species, the Lowland anoa and the Mountain anoa. Both are listed as Endangered by the IUCN, little is known about these animals but they are heavily hunted for food and their horns.
  • The babirusa, also known as 'pig-deer, comprises three species of pig. Each male babirusa sports a set of four tusks, two of which stick through their snout. All three species are threatened with extinction.
  • The mysterious and little-studied Sulawesi palm civet which is classified as Vulnerable. This predator lives and hunts in a wide-variety of habitats.
  • The Crested black macaque is called the most threatened primate on Sulawesi. It is killed for bushmeat and caught for the pet trade. In addition, deforestation and mining have taken a large toll on its habitat. They used to occur in groups of over 100, but no longer. The species is considered Critically Endangered.
  • The maleo is an Endangered chicken-sized bird. They nest in traditional sites, over a third of which have been abandoned recently due to human impact. They lay one massive egg in meter-deep pits, which humans sometimes poach for food.
Newly discovered species include the Togian White-eye, a small olive black and white passerine, which is likely endangered; the Togian hawk-owl in 2004; a rediscovered species of pygmy tarsier in 2000; and fifteen new species of beetles in 2005.

The island's biodiversity is ripe for more discovery and study.


According to Middleton et al 2019, Sulawesi has 5,972 described species of vascular plants, of which 2,225 are endemic.


Sulawesi is surrounded by rich seas with large habitats of seagrass and coral reefs. These habitats are home to leatherback, hawksbill, and green sea turtles, as well as dugongs and six of the world's seven giant clam species. Whales that use the waters as a by-way include sperm whales, pygmy sperm whales, and killer whales.

One of the marine biodiversity standouts is the Sulawesi coelacanth. This is the second species of the prehistoric survivor and is classified as Vulnerable by the IUCN Red List because it is threatened as bycatch. The coelacanth is not a target for fishermen.


Sulawesi has a startling diversity of forest types: fourteen different forest ecosystems have been identified. The wide diversity of forests is part of the reason for the islands high rate of endemism and biodiversity.

Mangrove forests: found in estuaries and along Sulawesi's large coastline. At one time mangroves covered much of the coastlines, but most of these have been lost.

Montane forests: rising above 1,000 meters these forests are some of the most intact forests in Sulawesi. Lower montane forests are primarily made up of oak and chestnut species, while upper montane forests support a variety of conifers.

Monsoon forests: this unique forest type is little-studied. It receives the lowest amount of rain in all Indonesia and is able to survive long droughts. However, much of this forest type has been lost to grazing land.

Ultrabasic forests: a unique forest type that grows on nutrient-poor ultrabasic soil with little plant diversity, but high endemism since unique plants—like pitcher plants—have evolved to fill this niche. Ultrabasic forests are made up of short twisted trees. Few fauna live here.

Limestone forests: shallow soil and steep slopes make these forests low both in abundance and diversity. They are home to some endemic species like snails.

Peat swamp forest: though Sulawesi only has small areas of peat swamp forests they contain high biodiversity, especially of birds.

Freshwater swamp forests: like peat swamp forests, freshwater forests only cover a small area of Sulawesi. They are made up of palms, pandanus, and pitcher plants.


Approximately 80 percent of Sulawesi's forests are either gone or degraded to some degree. Over 50 percent are considered in poor condition, while 30 percent—mostly in the highlands (above 1500 meters)—are classified as in good condition.

Over 95 percent of Sulawesi's mangrove forests and lowland forests are disturbed. In less than a decade—between the mid 1980s and 1993—Sulawesi mangroves have been decreased by over 60 percent in part due to aquaculture for seafood such as shrimp.

Wetlands have suffered even worse: 99 percent of the island's wetlands are either gone or damaged.

Current rates of forest loss are lower than much of Indonesia, but this is primarily because much of the island's lowland forest was already gone by as early as 1985.

Forest loss is due primarily to logging and conversion. Beginning in the 1970s the government began supporting large-scale logging and vast agricultural projects. Since then migrants from urban areas to the countryside have converted large tracks of forest into cash crops such as coffee and cacao.

Million hectares200120102020Loss 2002-19% loss of 2001 cover
Primary forest area 9.8 9.5 9.0 0.8 8.2%
Tree cover area 15.6 15.5 14.3 1.3 8.3%



Large-scale loss of forest is not as big of a threat in Sulawesi as other islands in Indonesia, simply because there is relatively little forest left. However, deforestation of remaining forest would be catastrophic for the island's unique biodiversity, much of which are already threatened.

Since montane forests contain very few commercial species, they are relatively safe from loggers, but hunting, fires, and erosion due to cleared areas remain major threats.

Pollution and habitat destruction from mining poses a threat to biodiversity and ecosystem health. Mining is even reported to occur within the boundaries of protected areas.

Bushmeat hunting and poaching is a large issue for a number of endangered species, including anoa, babirusa, black crested macaques, and the maleo since its eggs are poached.

South Sulawesi, as opposed to north and central, is serviced by few parks and protected areas, leaving species and forests there particularly vulnerable.


Sulawesi has six national parks and nineteen nature reserves.

Central Sulawesi contains the most well-known park on the island, Lore Lindu National Park spanning 229,000 hectares. It is a UNESCO Biosphere Reserve.

On the northern peninsula, Bogani Nani Wartabone National Park protects 300,000 square hectares, while Rawa Aopa Watmohai National Park protects 105,194 hectares in southeast Sulawesi.

Most of the parks, however, suffer frequent encroachment for illegal logging, mining, and even conversion into crops. Thousands of illegal gold miners have been found plying their trade in Bogani Nani Wartabone National Park.

Sulawesi also has three national marine parks: Bunaken, Wakatobi, and Take Bonerate.

Bunaken National Park includes islands, mangroves, seagrasses, and coral reefs. Taka Bonerate National Park protects the Taka Bonerate atoll (and surrounding coral reefs), the world's third largest atoll and the largest in Southeast Asia. Last but not least, Wakatobi National Park is made up of island chains and 25 coral reefs.


Forest and coconut plantation in North Sulawesi


Crested black macaque

Crested black macaque

Flying dragon


Indonesian rainforest in Sulawesi

Indonesian rainforest in Sulawesi

Indonesian rainforest in Sulawesi

Indonesian rainforest in Sulawesi

Green Vine Snake

Male and Female Knobbed Hornbill

Strangler fig

Mother tarsier and baby


More images at the Sulawesi slideshow



  • Charles H. Cannon, Marcy Summers, John R. Harting, and Paul J.A. Kessler (2007). "Developing Conservation Priorities Based on Forest Type, Condition, and Threats in a Poorly Known Ecoregion: Sulawesi, Indonesia". Biotropica online 25 May to June 25, 2007.
  • Daws, Gavan and Marty Fujita. Archipelago: the Islands of Indonesia. University of California Press, Berkeley and Los Angeles. 1999.
  • Erdmann, M. 2008. Latimeria menadoensis. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2.
  • Indonesian Biodiversity Strategy and Action Plan, 2003.
  • Indonesia National Socioeconomic Survey (SUSENAS), 2004.
  • Report on Biodiversity and Tropical Forests in Indonesia, USAID/Indonesia, 2004. Prepared by : (1) Steve Rhee, M.E.Sc. (2) Darrell Kitchener, Ph.D. (3) Tim Brown, Ph.D. (4) Reed Merrill, M.Sc. (5) Russ Dilts, Ph.D. (6) Stacey Tighe, Ph.D.
  • Ruud de Lang, Gernot Vogel. The Snakes of Sulawesi. Herpetologia Bonnensis II. Proceedings of the 13th Congress of the Societas Europaea Herpetologica. pp. 35-38. (2006)
  • Semiadi, G., Mannullang, B., Burton, J., Schreiber, A., Mustari, A.H. & the IUCN SSC Asian Wild Cattle Specialist Group 2008. Bubalus depressicornis. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2.
  • Supriatna, J. & Andayani, N. 2008. Macaca nigra. In: IUCN 2009. IUCN Red List of Threatened Species. Version 2009.2.

    Sulawesi conservation news

    For Indonesian farmers used to ‘instant’ results, going organic is a tough sell (02 Nov 2021 15:10:32 +0000)
    - Encouraging greater take-up of composting and other natural farming techniques in South Sulawesi province is challenging due to a long-standing reliance on chemical fertilizers and pesticides.
    - But farmers are increasingly looking to new methods owing to the scarcity and rising cost of agrochemical products.
    - The South Sulawesi parliament is drafting new rules to nurture composting in the province’s agricultural production.
    - Fieldworkers say farmers need government support as they adopt alternative methods.

    Study shows how sustainable livelihood programs for Indonesian fishers can succeed (26 Aug 2021 15:20:04 +0000)
    - Projects offering alternative livelihoods to fishers in Indonesia tend to succeed when they work closely with local NGOs and link participants to markets where they can sell what they produce.
    - That’s the finding of a new study that looks at what makes successful sustainable livelihoods interventions tick, including partnership with local people to develop their skills and leverage traditional resource-management knowledge.
    - Projects that failed tended not to understand the social context in which they were situated, including gender dynamics, resource and land-tenure systems, and the desires of local fishers.
    - The study authors say the findings highlight best practices for alternative-livelihoods projects and are important given that communities with negative past experiences of such projects are less likely to engage with them again in the future.

    Climate change threatens to squeeze out Indonesia’s medicinal plants (18 Aug 2021 15:22:02 +0000)
    - More than half of medicinal plant species in Indonesia won’t be able to grow in most of their current range by 2050 due to climate change, a new study says.
    - Researchers say medicinal plant species on the islands of New Guinea, Java and Sulawesi will see the largest reduction in distribution area, in part due to sea level rise in these regions.
    - The economic value of medicinal plants in Indonesia, coupled with other threats and a lack of resources for their conservation, makes it urgent that active conservation programs be put in place, the researchers say.
    - Medicinal plants are valuable species not only for personal health but also for their economic value as they are traded by local and Indigenous communities.

    Indonesian farmers refuse to budge for train line through karst landscape (16 Aug 2021 10:39:04 +0000)
    - Farmers in Indonesia’s South Sulawesi province have rejected government offers to buy their land for a railway project, saying they depend on it for their livelihood.
    - The residents of Salenrang village say protecting their lands and farms will be more beneficial than selling them for the railway line, which the government is touting as a boost for the economy.
    - The farmers also say the government is shortchanging them with its offers, arguing that the market rate for the land is more than five times higher.
    - The land conflict in Salenrang village is one of hundreds that have popped up across Sulawesi as the government splurges on infrastructure projects.

    In Indonesia, an unassuming brown bird is proof of turbo-charged evolution (10 Aug 2021 23:59:25 +0000)
    - Scientists are proposing to add two new subspecies to four existing ones within the Sulawesi babbler (Pellorneum celebense) species.
    - The team identified the new subspecies based on differences in DNA, body measurements and song recordings from dozens of babblers.
    - Taxonomic implications aside, the study also sheds light on the phenomenon of rapid evolution, as the babblers’ genetic divergence occurred over just tens of thousands of years, rather than millions.
    - But the nickel-rich soils believed to have given rise to the birds’ divergence could be hastening its demise, with mining companies eyeing their habitats for resource extraction.

    Maleos bounce back in Sulawesi after villagers resolve to protect their eggs (09 Aug 2021 10:35:10 +0000)
    - The maleo (Macrocephalon maleo), an endangered bird endemic to Sulawesi, Indonesia, lays a single gigantic egg in a hole that is then incubated solely by the geothermal heat in the sand or soil.
    - Maleo eggs are prized as a high-status delicacy and are frequently dug up to be eaten or sold illegally online, consequently pushing maleo populations into rapid decline.
    - Two community-led projects that protect maleo nesting grounds from poaching and ensure maleos can nest naturally have reported the first sustained increases in maleo numbers due to conservation efforts.
    - The projects have quadrupled and tripled local maleo numbers over a 14-year and five-year period, respectively, and experts are calling for other maleo conservation projects across Sulawesi to adopt this community-led, low-intervention method.

    Indonesia’s Gorontalo road runs into forest, swerves environmental checks (26 Jul 2021 10:41:06 +0000)
    - Designated a national strategic project, the Gorontalo Outer Ring Road will connect the main air and seaports in Sulawesi Island’s Gorontalo province.
    - Divided into three segments, the 45-kilometer (28-mile) road cuts through steep karst features, agricultural fields, informal settlements, and areas of protected forest.
    - The project has already been plagued by graft linked to land acquisition, and construction remains unfinished.
    - Now officials say that the project has not complied with legally mandated environmental checks.

    A road project in Indonesia’s Gorontalo carves a path of graft and grief (14 Jul 2021 16:59:53 +0000)
    - More than 1,000 families were entitled to payments for land needed to construct the Gorontalo Outer Ring Road, a national priority infrastructure project on Indonesia’s Sulawesi Island.
    - The road will connect Djalaluddin Airport in the capital of Gorontalo province with the province’s main ferry port.
    - Spending on the project reached almost 1 trillion rupiah ($69 million) between 2014 and 2017.
    - A senior provincial official and two surveyors have been jailed in connections with corruption in the land acquisition process, while another top official is also standing trial.

    Illegal loggers use pandemic as cover to ramp up activity in Sulawesi (24 May 2021 12:52:37 +0000)
    - Illegal logging on Indonesia’s Sulawesi Island has intensified by more than two-thirds during the COVID-19 pandemic, according to a local NGO.
    - It attributes this increase to monitoring by law enforcers having to be scaled back as part of wider mobility restrictions imposed in response to the pandemic.
    - At the same time, the legal logging industry has taken a hit due to sluggish demand and being undercut by the illegal trade.
    - Police have charged a senior local politician with involvement in illegal logging.

    Getting hands-on with pollination can boost cocoa yields, study shows (08 Mar 2021 17:30:40 +0000)
    - Less than 10% of flowers in a cocoa tree are pollinated in natural conditions. Efforts to bolster the yields traditionally involved breeding programs or the use of fertilizers and other chemicals.
    - A new study on Indonesian cocoa farms took a different approach: pollinating by hand. Researchers compared cocoa yields using their hands-on process versus traditional farming practices.
    - Hand pollination increased cocoa fruit yields by 51% to 161%. Even considering the cost of hand-pollination efforts, small-scale farmers had markedly higher incomes from the hands-on approach.

    Indonesian governor’s arrest in road project points to more tainted contracts (04 Mar 2021 03:50:02 +0000)
    - Indonesian anti-graft investigators last week arrested Nurdin Abdullah, the governor of South Sulawesi province, for alleged corruption in an upcoming road project in the province.
    - They have charged him with taking at least 2 billion rupiah ($140,000) in bribes to grant the contract to a local developer, and another 3.4 billion rupiah ($238,000) from other companies awarded other contracts.
    - Environmental activists are calling on the agency to expand the investigation to include other infrastructure projects approved by Nurdin.
    - Corruption in infrastructure projects is common in Indonesia, with local leaders like governors and district chiefs channeling the money back to their parties or using it to fund their re-election campaigns.

    Southeast Asian wild pigs confront deadly African swine fever epidemic (12 Feb 2021 04:16:16 +0000)
    - A recent study in the journal Conservation Letters warns that African swine fever, responsible for millions of pig deaths in mainland Asia since 2018, now endangers 11 wild pig species living in Southeast Asia.
    - These pig species generally have low populations naturally, and their numbers have dwindled further due to hunting and loss of habitat.
    - The authors of the study contend that losing these species could hurt local economies and food security.
    - Southeast Asia’s wild pigs are also important ecosystem engineers that till the soil and encourage plant life, and they are prey for critically endangered predators such as the Sumatran tiger and the Javan leopard.

    Rescue of rare white tarsier raises fears of habitat loss, illegal pet trade (10 Feb 2021 21:40:06 +0000)
    - Conservation authorities in Indonesia have rescued a baby tarsier from a fruit garden in the island of Sulawesi.
    - The Gursky’s spectral tarsier has been diagnosed with leucism, a condition similar to albinism, which gives it bright white fur.
    - The discovery has prompted mounting calls from conservationists for the protection of the rescued tarsier against wildlife traffickers and its habitat against degradation.

    Whale shark stranding points to silting of Indonesia’s Kendari Bay (13 Jan 2021 18:33:23 +0000)
    - Volunteers and officials successfully pushed a whale shark back out to sea after it got stranded in shallow water in Indonesia’s Kendari Bay.
    - The incident, which one rescuer said was a first, has highlighted the consequences of the rapid silting of the bay amid a spate of development projects in the area.
    - The clearing of land allows dirt to run into waterways, with the accumulated sediment halving the depth of Kendari Bay and making flood prevention more difficult.
    - Amid the silting, fishing catches have declined and there are indications of heavy-metal contamination of the water.

    Agribusiness giants ADM, Bunge trading in ‘conflict’ palm oil, report says (04 Jan 2021 11:27:36 +0000)
    - A report by Global Witness has found that more than 100 Indonesian palm oil mills supplying agribusiness giants ADM and Bunge have been accused of land and human rights violations and environmental destruction.
    - Global Witness found that neither company is addressing the majority of these allegations through their formal grievance processes, and effectively passing on this “conflict” palm oil to major consumer brands such as Nestlé, Unilever and PepsiCo.
    - ADM and Bunge have denied any failure to police their suppliers, but have also pledged to look into the allegations.