Malaysia's Forgotten Arks Of Biodiversity

Spotlight By Mary-Ruth Low and Gopalasamy Reuben Clements

In Malaysia, karst habitats only occupy less than 1 percent of the country’s land area (Schiltuizen 2000). Yet, the country features the world’s largest cave chamber by area, the Good Luck Cave. Its neighbour, Clearwater Cave, is the world’s 8th longest cave at 215km. Both are located in Gunung Mulu National Park in Sarawak, Malaysian Borneo, which was declared a World Heritage Site in 2001.

It is not uncommon for one to have phrase“Malaysia, Truly Asia” sung to you in response to your answer that Malaysia is your country of origin while traveling abroad. The catchy sing-a-long phrase was coined and composed by the Malaysian Tourism Board in 1999. And by the looks of it, the campaign has successfully caught on with travellers around the world.

Often shown onboard Malaysian Airline flights, the advertisement with this catchphrase features dancing indigenous Ibans in traditional dress, then panning across misty rainforest landscapes at dawn, before a turtle dives in crystal clear blue waters bordering white sandy beaches.

But we find ourselves asking, what does being “Truly Asia” mean? Is Malaysian’s biodiversity truly representative of what Asia has to offer?

Megadiverse Malaysia

With 210 mammal species, 250 reptile species, 620 bird species and 8500 species of vasuclar plants, Malaysia certainly deserves its recognition as a megadiverse country.

In terms of ecosystems, rainforests and coral reefs are frequently highlighted in the media as Malaysia’s wonderful destinations. However, many of the country’s equally unique ecosystems such as mangroves and peat swamps are often overlooked, probably because they are less picturesque and are filled with more bloodsucking insects.

Limestone karsts are an example of an ecosystem that lies somewhere in between.

Regarded as ‘arks of biodiversity’ (Clements et al. 2006), limestone karsts form spectacular backdrops with towering features and massive cave networks, but somehow still lag in popularity behind more postcard–worthy landscapes.

Ancient Worlds

Formed millions years ago, karsts are the result of calcium secretions of marine animals such as corals, lifted up above sea level by tectonic plate movements. The cream - coloured fissured cliffs crowned with jagged peaks and tufts of lush dark green vegetation are a sight to behold.

Southeast Asia alone has 40 million hectares of limestone karsts, of which about 13 percent are protected. Few are aware that karsts comprise eight out of twelve of the World Heritage natural sites in Southeast Asia.

In Malaysia, karst habitats only occupy less than 1 percent of the country’s land area (Schiltuizen 2000). Yet, the country features the world’s largest cave chamber by area, the Good Luck Cave. Its neighbour, Clearwater Cave, is the world’s 8th longest cave at 215km. Both are located in Gunung Mulu National Park in Sarawak, Malaysian Borneo, which was declared a World Heritage Site in 2001.

A popular tourist destination, the Mulu Caves receive 20,000 annual visitors on average.


Very little sunlight penetrates caves, yet within them thrives a vast assemblage of vertebrates and invertebrates. Having limited abilities to disperse, and having to adapt to the highly alkaline conditions and low levels of organic material, many species become endemic or restricted to one or few cavesover millenia.

In fact, some cave animals depend entirely on bat droppings — also known as guano — as their main source of food. These subterranean ecosystems are generally stable and resistant, allowing what scientists call ‘relict fauna’ to persist. Gunung Mulu National Park alone hosts some 200 cave species — mostly invertebrates — belonging to ancient animal groups that no longer occur on the surface.

Oustide caves, the calcium-rich soils of karst ecosystems are also optimal for the growth of endemic land snail species. In Borneo, almost all land snails are found only exclusively in karst habitats. In Peninsular Malaysia, one of these karst-endemic landsnails is so bizzare, it was voted the world’s top 10 species discovered in 2008 (Clements et al. 2008).

And scientists continue to make new discoveries of karst - endemic animals each year. One such finding was just published in 2014: the bent-toed gecko Cyrtodactylus metropolis, so named because it can only be found in Batu Caves, a distinctive feature of Kuala Lumpur’s cityscape. These caves are also home to the Batu Caves trapdoor spider, Liphistius batuensis, what the Guinness’ Book of Records deemed ‘the world’s rarest spider’.

Agricultural Aid

Karsts are not home to just endemic animals. Many species of bats typically found in the forests also roost in limestone caves, flying in droves out of caves at twilight to feed on insects, fruit or nectar, depending on the species. Insect-bats help keep unwanted pests numbers down in padi fields, while nectar-feeders play crucial roles as pollinators. One such species, the dawn nectar bat Eonycteris spelaea, is a major pollinator of the durian (Durio zibethinus).

An outsider might not think too highly of the durian except that it is a pungent - smelling throny fruit, but many Malaysians might be inclined to agree that the durian is a crucial part of our national pride and identity. Perhaps if more people could draw the links between conserving karst ecosystems and a good durian harvest, more limestone hills might receive better protection!

Archaeological and Religious Wonders

Interestingly enough, majority of the cave networks in Malaysia remain unexplored, despite the huge potential for archaeological and paleontological findings. In the state of Perak, the ‘Perak Man’, the only complete human skeleton to be found in Malaysia ,was uncovered in Gua Gunung Runtuh, loosely translated as the ‘Cave of the Crumbling Mountain’. The skeleton is dated between ten to eleven thousand years old, dating the artefact to the Paleolithic period. In the state of Terengganu, another human skeleton, presumably older than Perak Man, was discovered in Gua Bewah.

Limestone caves also provide a spiritual sanctuary and are associated with Buddhist and Hindu temples. In the state of Selangor, Batu Caves is home to Malaysia’s most iconic temple — the 46m tall statue of the Hindu deity, Lord Murugan, stands at the foot of the hill with the famous flight of 272 steps leading up to the temple cave at the top.

Saving Karsts - How and Where?

Conservation groups have not been idle in lobbying for protection of karsts. The IUCN Working Group on Cave and Karst Protection aims to “provide support, advice and liaison” on a global scale. Their 2008 publication provides guidelines for policy-makers and land managers on how to manage and conserve karst ecosystems.

Subterranean quarrying has been recommended as the way forward. Rather than blasting limestone hills with explosives, idle tin mining grounds can yield rich subsurface limestone stores. Three companies in Malaysia have already been carrying out limestone mining on old mining land in the state of Perak (Li, 2015). In fact, subsurface quarrying has beenfound it to be both “practical and economical”.

Until now, conservation plans for karsts were tricky to develop due to the lack of baseline data. Without historical information for comparison, karsts preservations have been on an ad hoc, reactionary basis. Scientists from the non-profit research group, Rimba, have been working to close the gap in information on karst ecosystems, first by identifying where the karsts are. Utilising remote sensing technology, scientists have mapped out a compilation of karstic areas in Malaysia, allowing them to identify and prioritise karsts in urgent need for protection (Liew et al. 2016).

Rays of Hope

The conservation success story of the Dark Caves right in the heart of the country’s capital sets a precedent in which we hope similar stories will follow. Part of the Batu Caves massif, the Dark Cave is a 2 km-long network of multiple caverns. Before 2011, it was freely accessible to the public but cave conservations soon realised that the marble walls were being heavily vandalised and stalagmites were being even carted off!

The Malaysian Nature Society campaigned for its preservation and today visitors can choose to either attend an educational or adventure tour for a minimal fee, organised and managed by the non-profit Cave Management group. The fauna of the Dark Cave was even featured in the New York Times in October 2012, with its endemic spider receiving its most deserved limelight!

So, we find ourselves asking again, how are we ‘Truly Asia’? Like other Asian countries, Malaysia is striving for economic prosperity, but it cannot happen at the expense of environmental propserity. If we do not get serious about protecting limestone karsts, endemic flora and fauna will continue to disappear. And, lest we forget, our supply of rice and durian.

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