PREHISTORIC AND SOME LONG-GONE ORANG-UTANS OF SARAWAK

 “With what interest must every naturalist look forward to the time 

when the caves and tertiary deposits of the tropics may be thoroughly 

examined, and the past history and earliest appearance of the 

great man-like ape be at length made known.”

Alfred Russel Wallace, The Malay Archipelago, 1869.

AT THE BEGINNING AND IN BAU LIMESTONE AREA   

In a prelusive way, this anticipatory remark by the great traveller and naturalist, Alfred Russel Wallace (1823-1913), may have inspired a number of intrepid 19^th century naturalists into exploring the dark recesses of some caves in the tropics for the hidden fossils of the great apes, including those of the Orang-utans. It is remarkable to note that almost nothing was known about Orang-utan fossils, or for that matter where one should look for them at the time when Wallace, in his famous 1869 travelogue, penned these precursory words on pages of a chapter devoted to his field observations on wild Bornean Orang-utans in Sarawak.

The scientific world had to wait for almost a decade before any non-human great ape fossils recognizable as Orang-utans (genus Pongo) started to appear as a direct result of concerted efforts in cave palaeontological survey. This historic moment in the annals of fossil Orang-utans research took place in the Bau limestone area of Sarawak, about 35 km southwest of the capital of Kuching. Alfred Hart Everett (1848-98), an explorer-naturalist, who later made a career in British overseas colonial administration, was placed in charge of a scientific expedition, known as Borneo Cave Exploration. The main objective of the exploration, with financial support from learned societies back in Britain, was to investigate the caves in Borneo for their potential in yielding palaeontological and anthropological remains. In the course of the expedition (1878 to79), he explored some of the limestone caves around the Bau region, then a thriving gold mining area. He collected some animal remains from a number of cave sites, and also, as opportunities had arisen, purchased from local people some old materials which interested him.

The variety of animal skeletal remains represented in the collection that Everett amassed includes snakes, monitor lizards, bats, rats, porcupines, rhinoceroses, bearded pigs, deer, as well as other medium and large-sized mammals. Among the more interesting items are two skulls, some isolated teeth and skeletal remains of Orang-utans (Figure 1). Unfortunately, the exact provenance of some of the Orang-utan materials, especially those he purchased, including the two adult male skulls, could not be ascertained by him and later researchers. This historic collection of Orang-utan remains, which perhaps represents the first fossils from the genus Pongo known to the modern world, had not been scientifically studied until much later in the mid-1990s and onwards.

Figure 1: Orang-utan dental remains (left) and two skulls (right, upper and lower) purchased or collected by Alfred Hart Everett from cave sites at Jambusan and Paku, Bau limestone area, 1878-1879.

SIREH CAVE ARCHAEOLOGICAL SITE, SERIAN

    Not far from Bau, where Everett had collected the Orang-utan remains, was an archaeological site, located at the entrance of Sireh Cave (Figure 2) - a cave system within the limestone hill, Mount Nambi, in the Serian area, about 65 km southeast of Kuching. The archaeological potential of the site was first investigated by Benedict Sandin (1918-82) from the Sarawak Museum in 1954, followed by a fuller excavation in 1959, also by the Sarawak Museum, under the supervision of William G. Solheim II (1924-2014) and Tom Harrisson (1911-76). Animal remains from these excavations were examined and studied by the Earl of Cranbrook (V) over the years, and the presence of a single phalanx (finger/toe bone) of Orang-utan was identified among the zooarchaeological materials from the 1959 dig (see References). Radio-carbon dating samples from a renewed investigation of the site by Ipoi Datan (Sarawak Museum) in 1989 suggested that the archaeological layers that yielded animal remains may have ranged in age from as old as 5,000 to as young as 800 years old.            

Figure 2: Excavation trenches in the deep part of Sireh Cave entrance, Serian. One of the archaeological sites in Sarawak with prehistoric Orang-utan remains.

     The accumulation of medium-sized and large-sized animal remains, such as monkeys, wild boars, tapirs, and clouded leopards is assumed to represent ancient kitchen refuse discarded by people visiting the cave over thousands of years. None of these animals, including Orang-utans, is a cave dweller or would frequently visit or enter caves on their own accord. The apparent rarity of Orang-utan remains among the ancient culinary left-overs is more revealing and perhaps an indication that Orang-utans were naturally uncommon in the area, and therefore infrequently hunted for food. Only future excavations and further research on the full collections can tell whether the presence of a single phalanx did really signify an opportunistic hunt (owing to presumed low density of Orang-utans) or more a reflection of sampling bias and, generally, insufficient zooarchaeological investigation.

    Official historical records show that no wild Orang-utans have been reported to be present in the Bau and Serian areas since the 1950s. Not far to the east, in areas sandwiched between the tributaries of the Sadong and the Sebangan Rivers, wild populations were believed to have still persisted until as late as in the 1960s. However, recent studies reveal that presently, within Sarawak, wild living Orang-utans do not occur anywhere west of the Lupar River.

NIAH – THE ZOOARCHAEOLOGICAL RECORD AND MORE RECENT TIMES

    The great limestone hill, Mount Subis, with a height of 394 m above sea level, dominates the landscape of Niah National Park. Niah Great Cave, the largest cave system in the area, and its archaeological sites, however, are located within a small limestone outcrop (Bekajang Hill) separated from the northeast flank of Mount Subis by a steep north-south oriented gorge. Entrances (or mouths) to several of the larger cave passages of the Niah Great Cave had been, and, still are, the focus of intensive archaeological excavations and investigations since the pioneering work there in the 1950s by teams of researchers from the Sarawak Museum led by Tom (1911-1976) and Barbara Harrisson (1922-2015). As a result of this continuous and long history of research, Niah has yielded the longest record of prehistoric human activity in Borneo, ranging in age, from the Late Pleistocene to Metal Age (from circa 45,000 to 500 years before present). The amount and diversity of materials collected and studied, which includes human skeletal remains, prehistoric cultural artefacts, botanical, and zooarchaeological remains of both wild and domesticated species, are unprecedented in the history of prehistoric study in Borneo. For example, up to now, skeletal remains from a diverse prehistoric fauna of about 142 different kinds of vertebrates (excluding fishes and humans) have been recorded from the Niah archaeological layers, including some regionally and globally extinct mammal species, such as tapir, tiger, and the giant pangolin.

    Niah archaeological sites that yielded Orang-utan remains include West Mouth, Gan Kira, and Lobang Angus. A total of about 120 dental and cranial remains (Figure 3) were on record. This number is unlikely to be the final figure since there are also bones from other parts of the skeleton that have yet to be identified and studied. Their remains occur throughout the excavated archaeological profile at West Mouth, and were among the mammal species that were most often hunted and consumed by the early modern humans (Homo sapiens) who frequented that site. Some skeletal remains still bear the signs and evidence of prehistoric consumption, in the form of cut and burnt marks on bones. A comprehensive study of the Orang-utan materials shows that many of the hunted animals were non-adults, and, in some instances where sex can be determined, predominantly female. The results, in combination with the fact that modern-day Niah forests support no living Orang-utan, seem to suggest that continued removal of juveniles and breeding females from a population of slow-breeding large mammals, as the Orang-utans are, can lead to their ultimate extermination from an area.  

Figure 3: Representative examples of prehistoric Orang-utan dental and cranial remains of juvenile and adult individuals from a number of archaeological sites in Niah (Lobang Angus, West Mouth, and Gan Kira) excavated by Sarawak Museum teams led by Tom and Barbara Harrisson since 1957. Specimens not to scale.

    When did Orang-utans last appear in Niah? Or, is there any surviving historical record which may indicate that in the not-so-distant past, the great ape still lingered in the forests around the area? In 2018, a tantalizing clue came to me while I was studying some museum collections in the UK for my dissertation project. The specimens in question include an isolated mandible (Figure 4) and complete bones from other parts of the skeletons of more than one individual. Information from associated label and a note written on the mandible indicate that these modern bones from Niah were gathered by Charles Hose (1863-1929), a veteran field naturalist and administrator in Brooke Sarawak, after the skins of the animals were kept by a party of museum collectors suspected to be from the United States of America. He then sent these skeletal specimens to Wynfrid Lawrence Henry Duckworth (1870-1956), an anatomist in the University of Cambridge.

Figure 4: A lower jaw (mandible) of an adult male individual with some of the dentition - the last known record of modern Bornean Orang-utan (Pongo pygmaeus) from Niah area, circa late 19^th century, collected by Charles Hose.

    The completeness of these bones and the general characters in colour and texture rule out the possibility that they were excavated from the archaeological deposits. If the information on the label, presumably added by Duckworth at a much later date, were reliable and accurate, then, as suggested by one of my colleagues, the likely museum collectors alluded to in the label, but never were identified confidently, could possibly be William Henry Furness III (1866-1920) and Hiram Milliken Hiller (1867-1921). In 1896, they jointly explored various parts of Sarawak, including Niah, with the aim of collecting ethnographic and zoological specimens for the University of Pennsylvania.

    It is surprising that Hose and Duckworth, or any later scholars who studied the materials, seem to fail to grasp the importance of the geographic origin of the specimens. Even more so when it is almost universally believed that there have been no historical records of Orang-utans within 200 km radius of Niah. For the moment, the Hose materials appear to be the only representatives of modern Orang-utans ever having been recorded from Niah in recent times. More associated materials perhaps still await to be discovered in the collections of the Academy of Natural Sciences of Philadelphia and the Pennsylvania University Museum, the two places where most of the zoological specimens from the Furness-Hiller Borneo expeditions are now kept.

LONG DEAD BUT USEFUL MATERIALS

Remains of prehistoric Orang-utans had also been found in a number of states in Peninsular Malaysia and in Sabah. Though so far Sarawak has recorded only about 12 palaeontological or archaeological sites with remains of prehistoric Orang-utans, the region still yielded the greatest number of specimens as compared to other regions/states in Malaysia. On-going in-depth scientific research using the rich prehistoric Orang-utan collection from Sarawak includes comprehensive documentation of the past geographic distribution and palaeo-demography of the genus in the region, palaeo-DNA and palaeo-protein investigations of prehistoric populations, and also dental micro-histological studies that may reveal potential adaptive changes in life history strategies among different populations of Orang-utans through geological times and environmental change. Results from these different lines of scientific investigation will surely enrich our knowledge about Orang-utans and their responses to past anthropogenic and natural disturbances. This in turn will lead to better conservation management and intervention to ensure the long-term survival of the great ape in Sarawak.  

Historical records clearly show that Sarawak had, as early as in the 1878/9, made her important contribution towards scientific investigation of Orang-utans fossils. Sarawak, with her unique prehistoric collection and many places yet to be explored, has a bright future to continue with this good tradition.

REFERENCES

Cranbrook, 5^th Earl of, (2012) ‘Sireh cave bone in retrospect: bone, teeth and other remains from Sarawak Museum excavations of 1954 and 1959’. Sarawak Museum Journal 70 (n.s. 91), pp. 55-87.

Cranbrook, 5^th Earl of, (2013) ‘The ‘Everett Collection from Borneo Caves’ in the Natural History Museum, London: its origin, composition and potential for research’. Journal of the Malaysian Branch of the Royal Asiatic Society 86 (1), pp. 79-112.

Drawhorn, G.M. (1995) The Systematics and Paleodemography of Fossil Orangutans (Genus Pongo). Unpublished PhD dissertation, University of California.

Harrison, T. (2000) ‘Archaeological and ecological implications of the primate fauna from prehistoric sites in Borneo’. Bulletin of the Indo-Pacific Prehistory Association 20, pp. 133-146.

Hooijer, D.A. (1960) ‘The orang-utan in Niah cave pre-history’. Sarawak Museum Journal 9 (n.s. 15-16), pp. 408-421.

Katz, A. (1988) ‘Borneo to Philadelphia: the Furness-Hiller-Harrison collections’. Expedition 30 (1), pp. 65-72.

Lim, T.T. (2018) Mortality Profiling of Orangutan (Pongo) Zooarchaeological Remains from Niah Caves, Sarawak, Malaysian Borneo. Unpublished MPhil. dissertation, University of Cambridge.

Piper, P.J. and Lim, T.T. (2021) ‘Zooarchaeology at Niah Cave: contributions to our understanding of southeast Asian prehistory’. Malayan Nature Journal 81^st Anniversary Special Issue, pp. 195-208.

ACKNOWLEDGEMENTS

        I thank the Kuching branch of the Malaysian Nature Society for the kind invitation to contribute to this issue of Malaysian Naturalist. Much of the research work on the subject was carried out during my postgraduate study in the University of Cambridge (2017-18), followed by a one-year fellowship with the Sarawak Museum Department’s Sarawak Museum Campus Project & Heritage Trail. The State Planning Unit at the Chief Minister’s Department of Sarawak is thanked for granting a research permit “(81) JKM/SPU/608-8/2/2 Vol. 2” and its extension “(90) JKM/SPU/608-8/2/2 Vol. 3” to conduct research in Sarawak. My sincere thanks to the 5^th Earl of Cranbrook for his help in facilitating research trips to the Natural History Museum (London) to study the Everett collection in 2009 and 2018; Francis Peter Anak Sambong and Mohd Sherman bin Sauffi, both from Sarawak Museum Department, who invited me to join them in a brief visit to Sireh Cave archaeological site in 2019; Gerrell Drawhorn for his insightful discussion about the potential original collector(s) of the Niah modern Orang-utans; Joshua Pandong (Wildlife Conservation Society Malaysia) for sharing useful information on past and present research on Orang-utans in Sarawak. I dedicate this article to the Late Michael Chieng Jing Eng of Miri, in fond memories of our visit to Niah National Park and the archaeological sites in 2019.

NOTE: Original article published in 'Malaysian Naturalist - Sarawak's Biodiversity At A Glance'; Dec. 2021, Feb. 2022 & Sept.-Nov. 2022; Combined volume 75-2 & 76-1.