Article

Mammals

From Munshipedia, the MBRAS digital historical encyclopedia

Mammals

The mammals of the Malay Peninsula and Borneo constitute a fauna of considerable taxonomic richness and ecological complexity, documented in the Society’s journals from the late nineteenth century through the late twentieth century. The region supports diverse assemblages ranging from small insectivores and rodents to large ungulates and carnivores, with pronounced endemism in montane and insular settings [1], [2], [3]. Mammals in this region have served not only as objects of scientific inquiry but also as agents of ecological processes such as seed dispersal [4], as subsistence resources for forest-dwelling communities [5], and as cultural artefacts in funerary and ceremonial practice extending back at least three millennia [6]. The literature spans rapid taxonomic description, field ecology, biogeographic analysis, and osteological archaeology, reflecting shifting disciplinary priorities across more than a century of investigation.

Members & Sub-Topics

Taxonomic Discovery and Species Richness

The early twentieth century was characterised by intensive collecting expeditions that yielded large numbers of new mammal taxa, particularly from poorly sampled highland and insular localities. Kloss and Robinson’s 1916 preliminary diagnoses, based on their February–June 1914 expedition to Korinchi Peak in West Sumatra, formally established sixteen new mammal taxa, including eleven new species of spinifex rat in the genus Epimys and a new genus of rat, Oromys [1, pp. 269–275]. The extraordinary concentration of novelty in a single genus underscored the inadequacy of prior sampling in Sumatran montane forests and suggested that the Barisan highlands constituted a distinct biogeographic unit [1]. Specimens were collected across an altitudinal range from sea level at Pasir Ganting to 10,000 feet on Korinchi Peak, with the majority of new Epimys species gathered between 3,100 and 7,300 feet [1, pp. 269–275].

In Borneo, Chasen and Kloss (1928) determined mammalian specimens collected by H. C. Siebers during the 1925 Middle-East Borneo Expedition, describing two new subspecies of pygmy squirrel (Nannosciurus melanotus pallidus and N. exilis sordidus) and resolving nomenclatural confusion in several Bornean carnivores, rodents, and insectivores [2, pp. 38–49]. The material, drawn from the Telen River drainage in the Samarinda division, extended from Tenggarong at sea level to Punt D at 1,172 metres [2]. The authors rejected several previously proposed subspecies on the grounds that individual variation in size was too great for dimensional distinctions to be reliable on small samples, as in the case of the palm civet and the short-tailed mongoose [2, pp. 39–40].

Moulton’s 1912 account of the Batu Lawi expedition in the Limbang district of Sarawak documented mammal specimens from a 40-day journey through an area of extreme remoteness where, as Moulton noted, “no white men and but few natives had ever ventured before” [7, p. 12]. The collection, though small in absolute numbers, was “surprisingly rich in new and rare species” for the region [7, p. 56]. Notable records included a pig-tailed macaque (Macacus nemestrinus) and a bushy-tailed squirrel (Rhithrosciurus macrotis) collected at 2,100 feet, a Javanese pangolin (Manis javanica) captured by dogs, fresh rhinoceros traces on the slopes of Batu Lawi, and tiger-cat tracks observed near the summit at approximately 5,660 feet [7, pp. 30–31].

Ecological Roles and Behaviour

Ridley’s 1894 study of seed dispersal by mammals remains one of the earliest and most comprehensive treatments of mammal–plant interactions in the region. Drawing on extensive field observations across the Malay Peninsula, Ridley argued that mammals—though secondary to birds—constituted a significant and evolutionarily formative agent of seed dispersal in tropical forests [4]. His central thesis was that the morphological characteristics of mammal-dispersed fruits (dull colouration, large size, smooth or slippery surfaces) represented adaptive responses to the foraging behaviours of monkeys, bears, squirrels, civets, and bats [4]. A recurring analytical thread contrasted mammal-dispersed fruits (plain green, large, inconspicuous) with bird-dispersed fruits (scarlet, orange, small), which Ridley attributed to the different sensory modalities and flight altitudes of the two groups [4].

Ridley documented the foraging behaviour of the long-tailed macaque (Macacus cynomolgus) on Willughbeia, Dialium, Nephelium, and Eugenia; the bear’s (Helarctos malayanus) destruction of Durio fruit; and the civet’s role in coffee dispersal [4]. He recorded the musang (Viverra malaccensis) passing intact seeds of coffee, Gnetum scandens, Caryota Cumingii, and Mimusops elengi in its excreta, and noted that planters deliberately collected these seeds for cultivation on the belief they produced stronger plants [4, p. 19]. His most extended analytical passage concerned the dispersal of oaks and chestnuts by squirrels, demonstrating that the smooth polished surface of Quercus lucida acorns and the fine silky coating of Q. encleisocarpa functioned as anti-handling adaptations: squirrels could not grip the fruit firmly enough to consume it, so the seed dropped and rolled away [4, pp. 25–26].

Pfeffer and Caldecott’s 1986 account of the bearded pig (Sus barbatus) in East Kalimantan and Sarawak provided the first detailed English-language treatment of the species’ ecology, translating and revising Pfeffer’s 1959 French-language field study and supplementing it with Caldecott’s more recent observations [5]. Pfeffer’s year-long field study (July 1956–July 1957) documented the pig’s morphology, diet, diurnal activity patterns, nest construction, reproductive behaviour, and its massive periodic migrations [5]. Two principal annual migration pulses were identified, occurring in August–September and December–January, with animals moving southward from the upper Sembakung, Sesayap, and Malinau basins along four principal routes toward the Mahakam [5, pp. 91–92]. During peak migration, herds of 20–30 or more crossed rivers simultaneously; in 1954, thousands of carcasses accumulated at Tanjung Selor [5, p. 94]. Caldecott proposed a “phenological mosaic” model in which submontane Lithocarpus (oak) forests acted as a nutritional subsidy fuelling both reproduction and long-distance movement [5]. In Sarawak, bearded pigs contributed 32 per cent of all meat and fish consumed at 63 interior boarding schools in 1984–1985, and at least 90 per cent of the estimated 54 kg of wild meat consumed per person per year in undisturbed areas [5, pp. 99–100].

Biogeography and Island Faunas

The distribution of mammal faunas across the Sunda Shelf and its offshore islands has been a persistent theme in the Society’s literature. Chasen (1941), responding to questions posed by Sir Richard Winstedt regarding prehistoric human movements, offered a zoo-geographical perspective on the diffusion of animal faunas as an analogue for human migration routes [8]. He argued that the present distribution of certain animals supported a movement through Borneo south to the Sunda shelf, after which the drift curled north-east, reaching islands off the west coast of Sumatra, North Sumatra, and possibly the Malay Peninsula [8]. He noted that where these eastern and western drifts met, closely related forms could coexist as distinct “species” maintained by physiological intolerance [8].

Chasen and Kloss (1928) established that the mammalian fauna of the Anamba Islands in the South China Sea was more closely allied to the Malay Peninsula than to the nearby Natuna Islands [3]. Their 1925 collection added twelve forms to the island group’s mammal list, raising the total from eighteen to thirty, and included four new subspecies: Tragulus kanchil siantanicus, T. k. anambensis, Sciurus tenuis siantanicus, and Rattus validus terempa [3, pp. 28]. The authors noted that indigenous mammals were “only rarely inseparable from those of the mainland,” with several forms showing subtle but consistent cranial or colour differences from their nearest continental counterparts [3].

Harrison (1965) applied the logarithmic series model of Fisher, Corbet and Williams to mammal collections from islands surrounding the Malay Peninsula, asking whether species richness could be predicted from area alone [9]. His critical finding was that inshore islands and those of North Borneo showed indices of diversity close to 10, statistically indistinguishable from the mainland fauna once sampling incompleteness was corrected, whereas offshore islands near or outside the 10-fathom contour consistently showed a lower index of approximately 7, reflecting a genuinely impoverished fauna that could not be explained by the standard Sunda Shelf submergence model [9, pp. 34–36].

Domestication and Cultural Significance

Lord Medway’s 1973 article established that domesticated pigs of Sus scrofa descent were present in Sarawak by the Neolithic period (c. 1165 BC) and that the ritual deposition of pig jaw-bones in funerary contexts persisted with remarkable continuity through to the Ming period and beyond [6]. Drawing on osteological specimens from Megala E and Lobang Kudih caves, Medway demonstrated that the pigs represented were not the indigenous bearded pig but imported domestic stock [6]. The Megala E pig jaw, from a Neolithic burial dated 1165 ± 240 BC, had post-canine teeth consistently smaller than those of the bearded pig in all dimensions except fourth premolar breadth, confirming its identity as a domestic Sus scrofa [6, pp. 165–166]. At Lobang Kudih, 112 jaw fragments representing at most 94 individual pigs were all ascribable to a distinctive, small domestic breed with unimodal tooth-length distributions indicating a homogeneous and stable population [6, pp. 167–169]. The toothrow of the Kudih pig was markedly foreshortened compared to the bearded pig: total jaw length ranged 168–187 mm versus 285–370 mm in S. barbatus [6, p. 170]. Modern domestic pigs from an Iban longhouse near Engkilili had permanent dentition falling within the range of the Kudih pig, confirming the continuity of this small breed in Sarawak to the present day [6, p. 170].

Research and Documentation

The Society’s literature on mammals reveals a trajectory from rapid taxonomic description in the early twentieth century toward increasingly integrative ecological, biogeographic, and archaeological approaches. The 1910s and 1920s were dominated by measurement-driven diagnoses intended to secure priority of naming before fuller monographs could be prepared, reflecting the period’s emphasis on collecting and description over ecological or biogeographic synthesis [1], [2], [3], [7]. Ridley’s 1894 study, while still descriptive in method, introduced an explicitly evolutionary framework for understanding mammal–plant coevolution that anticipated later quantitative dispersal studies [4]. The 1930s and 1940s saw the emergence of zoo-geographic reasoning, as in Chasen’s 1941 note linking faunal distributions to questions of human prehistory [8]. The post-war period brought statistical ecology into the field, exemplified by Harrison’s 1965 application of the logarithmic series to island mammal faunas [9]. By the 1970s and 1980s, the literature had matured into integrated studies combining field ecology, osteology, and ethnography, as in Medway’s 1973 synthesis of archaeological and ethnographic evidence for pig domestication [6] and Pfeffer and Caldecott’s 1986 account of bearded pig behaviour and its cultural significance [5]. Medway’s 1977 volume, Mammals of Borneo, stands as a comprehensive reference work consolidating the region’s mammalian fauna [10].

MBRAS Sources

References

  1. C.B. Kloss and H.C. Robinson (1916). Preliminary diagnoses of some new species and subspecies of mammals and birds obtained in Korinchi, West Sumatra, Feb-June 1914 JSBRAS 73: 269–278. Read on JSTOR
  2. F.N. Chasen and C.B. Kloss (1928). On some Carnivora, Rodentia and Insectivora principally from Eastern Borneo JMBRAS 6(1): 38–49. Read on JSTOR
  3. F.N. Chasen and C.B. Kloss (1928). On a collection of mammals from the Anamba Islands, South China Sea JMBRAS 6(3): 28–42. Read on JSTOR
  4. H.N. Ridley (1894). On the dispersal of seeds by mammals JSBRAS 25: 11–32.
  5. J. Caldecott and P. Pfeffer (1986). The bearded pig in East Kalimantan and Sarawak JMBRAS 59(2): 81–100.
  6. Gathorne Gathorne-Hardy, Lord (Earl of Cranbrook) Medway (1973). The antiquity of domesticated pigs in Sarawak JMBRAS 46(2): 169–178. Read on JSTOR
  7. J.C. Moulton (1912). Mammals taken on the Batu Lawi expedition JSBRAS 63: 72–73.
  8. F.N. Chasen (1941). A note on the northern “drifts” in the Malay Peninsula. Records of the Raffles Museum, No. 14 JMBRAS 19(1): 99–100.
  9. Harrison J.L (1965). Numbers of mammals on the Malaysian islands JMBRAS 38(2): 26–42. Read on JSTOR
  10. Lord Medway (1977). Mammals of Borneo : 172.