Asian elephants in Borneo and the missing fossil from Bau

Heritage Snippets of Sarawak by FoSM

Heritage Snippets of Sarawak

By LIM Tze Tshen

By size, the Asian elephant is the largest wild animal living in Borneo. Its natural geographic distribution in Asia encompasses Sri Lanka, India, Nepal, Bhutan, Bangladesh, Myanmar, China, Vietnam, Laos, Cambodia, Thailand, Peninsular Malaysia, Sumatra, Borneo, and, formerly, Java. Across the region, the species is known collectively and universally by its scientific name, Elephas maximus, irrespective of the place that an animal may come from. 


Within Borneo, the living Asian elephants are found exclusively in the northeastern part of the island, including certain areas in central, eastern, and southern Sabah, as well as adjacent areas in the northern part of North Kalimantan Province.

Figure 1: A family group of elephants feeding along the Kinabatangan River in eastern Sabah. Photo courtesy of Bullyap.

That is only about 5 per cent of the total land area of Borneo. The most recent study published in 2011 estimated the populations in Sabah ranged from 1,184 to 3,652 individuals, and there were less than 20 individuals left in North Kalimantan.

As consumers of grasses, leaves, and fruits, Asian elephants, with their wide home range, play an important part in tropical forest ecosystem as seed dispersal agents for certain plant species such as wild forest mangoes. Their foraging habits and long-distance movements across different landscapes also help in creating and maintaining a diversity of micro-habitats vital for the growth of multiple types of vegetation and small animals—for example, tadpoles that live in the watery pockmarks of old elephant trackways. For these reasons, they are often cited as natural gardeners.

The living elephants in Borneo are thought to be slightly different from their other Asian counterparts in certain aspects of their external morphology, such as smaller in overall body size, having a longer tail with tip often touching the ground, a more rounded body and sloping hind quarters, larger ears, and shorter trunk. In tusk-bearing mature males, it is believed that they often possess slender and straighter tusks. However, many of these characteristics have not been sufficient investigated by modern biologists. In other words, the scientific validity of these characters in identifying the elephants in Borneo as a distinct form is still unresolved.

Puzzling origins

The living elephants in Borneo have a baffling history of origins that is very much shrouded in mystery. Spenser St. John (1825-1910) suggested in his 1862 book, Life in the Forests of the Far East, that they were feral descendants of former gift animals presented to the Sultan of Sulu, who later deposited the animals or their offspring in northern Borneo around 1760 AD. This view was generally shared by two Borneo-based naturalists, Robert Shelford (1872–1912) and Edwards Banks (1903–1988), whom in their respective lives as curators of the Sarawak Museum had involved an elephant fossil discovered in Sarawak during the end of the 19th century – an intriguing piece of evidence that is crucial in understanding the history of Asian elephants in Borneo.  

In 2003 and 2018, results from two independent genetic studies conducted on living Asian elephants across the species’ distribution range, including individuals from Borneo, provided us with new and thought-provoking insights from a biomolecular perspective. Broadly speaking, the studies concluded that the living elephants in Borneo are genetically distinct from their living counterparts in other parts of Asia. One of the studies further suggested that they had evolved in isolation from other populations for at least the past 300,000 years. It, therefore, seems that the living elephants in Borneo are not descendants of imported stocks, but are truly native to the island.

Yet, as in any vibrant scientific investigation, that is not the end of the story. New scientific insights are expected to lead to new scientific questions to be asked, and new arenas to be explored.  

Some recent scholars had added a fascinating twist into the debate—they asked, what if the initial human-mediated introduction(s) into Borneo during historical periods involved elephants from the island of Java? 

According to them, Java had its native elephants isolated from the rest of the Asian populations since geological times. As a result, these Javan elephants were very likely genetically distinct from other populations. Unfortunately, they went extinct from Java since perhaps the end of the 18th century. For this reason, no living genetic materials of the Javan elephants were available to the two genetic studies mentioned above. 

If such translocation(s) did happen, as studies on historical text had suggested, then the nature of the Javan genetic distinctiveness may easily be misinterpreted as originated under a Bornean context.       

Clearly, the origin is still a perplexing riddle that no one yet has an answer. 

The fossil specimen from Bau—its fate and missed opportunities

The presence of fossilised remains of elephants in Borneo will undoubtedly add much substance to the discussion about their origins. That was precisely what had happened in the Bau area of Sarawak around 1898.

 

Figure 2: Limestone (karstic) landscape in Bau. © L.T. Tshen.


As reported in the Sarawak Gazette of January 3, 1899 on natural history specimens added to the collections of the Sarawak Museum: 

Some mammalian fossil remains from a cave at Bau, including a tooth of the Indian elephant. Presented by R. Pawle Esq.

The donor is very likely Reginald Pawle, a mining engineer from the Borneo Company. Probably sensing the importance of the finding, Robert Shelford, the curator of Sarawak Museum at that time, promptly wrote up a short note about this elephant fossil. He then published it in the June 1899 issue of the Journal of the Straits Branch of the Royal Asiatic Society. He stated that the fossil was found by a Chinaman in a small cave in Bau while washing for gold in the area, and it was subsequently handed over to the museum by Pawle. The note ended with the remark, ‘That the species was once indigenous to Borneo is proved now for the first time and beyond all manner of doubt.’ We also found a passage about it in his book, A Naturalist in Borneo, published posthumously in 1916.

A subsequent curator, Edwards Banks, initially thought that the specimen was lost, but managed to relocate it in the museum collections. He provided a brief account of it in his 1931 monograph, A Popular Account of the Mammals of Borneo

there is in the Museum here part of a fossil molar tooth of an Indian Elephant taken from a crevice in the limestone near Bau in Upper Sarawak; the specimen consists of four and part of a fifth distal sections of the first of the two premolars in the upper jaw and indicates that Elephants existed sometime ago in parts of Borneo where there are at present no other traces of them.

In the mid-1950s, when Tom Harrisson (1911-1976) was curator of the museum, the specimen was evidently sent for research purpose to a Sri Lankan palaeontologist, Paulus Deraniyagala (1900-1976), who was a specialist on South Asian mammal fossils, and also the director of the Sri Lanka national museum in Colombo. Deraniyagala dutifully produced a more refined study of the specimen, and published the results, together with other similar fossils from Sri Lanka, in his 1955 monograph. He appeared to be the last person who had seen the fossil as it cannot be located by recent scholars in the current collections of Sarawak Museum. It is possible that the specimen has never been returned and may still remain in the museum in Colombo. 

Fortunately for us, Deraniyagala included a number of monochrome images of the specimen in his monograph—so far, the only known pictorial documentation of the Bau specimen.

The monograph Deraniyagala published in 1955 that contains images of the fossil specimen found in Bau. Picture taken from the author’s copy of the monograph.

Careful assessment of these images confirms that his analysis and judgement about the detailed aspects of the fossil tooth are more accurate that Banks’.

Figure 4: (Left) The Bau fossil; (Right) Complete cheek tooth of modern Asian elephants from Peninsular Malaysia, in two views; (Middle) Reconstructed missing parts of the Bau specimen.

Alas, uncertainty about its current whereabouts means that much opportunity for state-of-the-art research will be lost. For example, it is impossible by now to subject it to various direct dating methods to gain knowledge about its exact geological age, or to perform biochemical studies (such as stable isotopic analyses) and high-resolution scanning to gain a better understanding of the paleodiet and pattern of biological growth of the fossil animal when it was alive. Frequently, such seemingly trivial information can be of great use for the conservation of modern species. 

Further actions?

Museum specimens, like the Bau fossil, are not and should not be treated as obsolete remains from bygone ages with no more active contribution to make to modern societies. Museums should serve as a safe and appropriate home for specimens so that their potential for future research is not compromised, and even function as a powerhouse generating new knowledge based on their collections. 

The loss of this unique specimen from Bau is unfortunate since it is not only a rare and scientifically important specimen but also an irreplaceable manifestation of the early contribution Sarawak had made towards regional palaeobiological science. When it is placed together with all other Proboscidean remains found across Borneo, and there were but few, the Bau specimen unquestionably has enriched our understanding of the past history of this large mammal in the island.

Figure 5: Prehistoric Proboscidean remains discovered in Borneo — including remains from the Asian elephant (Elephas maximus) and two of its extinct relatives, Stegolophodon lydekkeri and the Straight-tusked elephant, Palaeoloxodon. Estimated distribution range of the Asian elephants in Borneo around 1900 is marked in vinaceous red, whereas stippled area denotes the current range. © L.T. Tshen.

Winston Churchill once said, ‘If we open a quarrel between the past and the present, we shall find that we have lost the future.’ The Bau specimen may be one of the many beacons illuminating the way guiding us to a better understanding and protection of the globally endangered and evolutionary unique Asian elephants in Borneo.

It is hope that future undertakings—retracing the specimen in Colombo and/or further paleontological investigations in Bau limestone area—will remedy the condition,  and return one of the gems to her rightful seat in the pantheon of Sarawak natural heritage.

Postscript

The reconstructed ‘biographical sketch’ of the Bau fossil specimen would not be possible without the generosity kindly extended to me while conducting research on the history of the specimen and, more generally, on other Proboscidean fossils. I would like to record here my gratitude to the Sarawak Museum library, library of the Department of Museums Malaysia in Kuala Lumpur, and the main library of Universiti Malaya for access to their collections of rare and old publications, and to the Zoology Museum of the same university for access to their animal bones collection. This article is dedicated to the 5th Earl of Cranbrook for his 90th birthday and profound contributions to the study of Bornean prehistoric and modern-day mammals.

LIM Tze Tshen, honorary secretary of the Friends of Sarawak Museum, is a vertebrate palaeontologist and zooarchaeologist. He is reachable through limtzetshen<at>yahoo<dot>com.

“Heritage Snippets of Sarawak” is a fortnightly column.

— DayakDaily