Preliminary Observations and Status of the Pag Ai
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PRELIMINARY region of North Pagai studying the four sympatric Mentawai primates. In all there OBSERVATIONS AND were 47 encounters with macaques STATUS OF THE PAG AI totaling 17 hours of visual contact. MACAQUE The Mentawai macaque is the least Agustin Fuentes studied of the four endemic Mentawai Department of Anthropology primates and little has been published University of California, regarding its behavior and ecology. Berkeley, CA 94720 USA There appear to be two subspecies: M. and p. pagensis (Miller 1903), of the Monica Olson Pagais and Sipora, and M. p. siberu Department of Anthropology (Wilson and Wilson, 1976; Whitten and University of California Whitten, 1982), found on the northern Los Angeles, CA 90024 USA island of Siberut. Whitten and Whitten The Mentawai Islands are some of the (1982) describe the morphological most remote and little studied islands of differences between the two subspecies the Indonesian Archipelago. Lying 85 to and provide some basic socio-ecological 135 km off the coast of West Sumatra, data on the Siberut Island form. between 0.55’ and 3°20’ S, the four We saw five groups of Mentawai islands of Siberut, Sipora, North and macaques throughout the Betumonga South Pagai are host to four unique region. These groups ranged in size from primate species. All four of these species five to 25 animals, and the largest group (including one genus) are endemic to the had two adult males. Solitary males also Mentawai chain, each having evolved were seen on occasion. Most frequently separately from their Sumatran the groups split up into smaller foraging counterparts over the 10,000 to 500,000 units during the day and were seen en year isolation of the Mentawai Islands. masse only while feeding in coconut Two of the species, Kloss’s gibbon gardens or moving through primary (Hylobates klossii) and the Mentawai forest. The macaques fed on a variety of Island langur (Presbytis potenziani), plant species both in primary and have been the subject of doctoral secondary forests and in the gardens and dissertations and other research projects coconut groves surrounding villages. (Fuentes, 1994; Tenaza, 1975; Tilson, 1980; Whitten, 1982). The other two, Like the other Mentawai primates the the pig-tailed langur (Simias concolor) and the Mentawai macaque (Ma caca macaques frequently vocalized in the early morning hours, but they did not pagensis) have not been studied exhibit the multi-group vocal interactions intensively. This report presents common to the gibbons and langurs of observations on and conditions of the the archipelago. However, the macaques Mentawai macaque on North Pagai Island. did interact with both species of langurs, moving and feeding on occasion with Two observers, Agustin Fuentes (AF) langur groups. and Monica Olson (MO), observed M. pagensis on North Pagai Island during It has been suggested that the crested 1991 and 1992. AF spent three weeks on serpent eagle (Spilornis cbeela the Pagai Islands in 1989-90 surveying sipora) and the reticulated the region and seven months during 1992 python (Python reticulatus) are in southwestern North Pagai (Betumonga potential predators on the primates of the Mentawai region) studying the Mentawai Island Islands (Whitten and Whitten, 1982; WWF, 1980). There have been no langur (P. potenziani). MO spent four reports of any predation attempts by these months during 1991 in the Betumonga two species on any primates in the 1 The Pagai macaque (Macaca pagensis pagensis). Photo: Monica Olson. 2 Mentawai Islands, and no response by risk, even in the absence of hunting, M. pagensis to either of these predators because they rely on human crops and has been noted by any observer. It is groves as important food sources. As the most likely that humans are the only knowledge of traditional traps and predator on primates in the Mentawai poisons is lost by the younger Islands (Fuentes, 1994). Various generations and villages become researchers have noted the devastating increasingly reliant on cash crops for effect of humans on the Mentawai subsistence, the macaques face a greater primates (Mitchell and Tilson, 1986; risk. This risk is the widespread use of Tenaza, 1987, 1989; Whitten and imported chemical poisons (such as Whitten, 1982). Although macaques are Union Carbide’s Aldicarb) as anti not hunted frequently for food on the monkey pesticides. These poisons affect Pagai Islands (as compared with Siberut the macaques and many other potentially [see Whitten and Whitten, 1982]) they unique Mentawai forms in a much more often are poisoned or shot as crop pests indiscriminate manner than did the (Tenaza, 1987, 1989; Fuentes, pers. obs. traditional method. 1992). The macaques also have been affected deleteriously by the high rate of Our brief observations suggest that the deforestation on the Pagai Islands, where Pagai macaques are very similar, both up to 75% of the original forest cover has ecologically and behaviorally, to the been destroyed ar altered (Fuentes, 1994; macaques observed on Siberut. Tenaza, 1987). However, human influences are potentially greater and more devastating Because the macaques use the gardens in the Pagais than on Siberut. More and groves much more than do the other research is urgently needed on the Pagai Mentawai primates, they continue to be form of M. pagensis to ascertain any seen as pests by the local villagers. For potential subspecific differences for these macaques it is the combined threat conservation action. Additionally it is of poisoning by villagers and loss of important to inform the international habitat due to deforestation that brings community that the Pagais contain very them dangerously near the point of important, potentially unique, faunal extinction. WWF (1980) reports a elements within the Mentawai population of 39,000 macaques on Archipelago and stress that there is need Siberut but admits that it is at best an for conservation efforts throughout the educated guess and that the actual region. population may be significantly lower. Sipora has very few macaques left due to References over 90% deforestation and the transmigration of many Indonesian Fuentes, A. (1994) The Socioecology of settlers from other islands. The Pagais the Mentawai Island Langur (Presbytia have been heavily logged and lack any potenziani). Unpublished Ph.D. dissertation, complete census of their primate University of California, Berkeley. communities but are very likely to have Miller, G.S. Jr. (1903) Seventy new Malayan far fewer macaques than Siberut because mammals. Smithsonian Miscellaneous of the smaller land area and severely Collection 45:1-43. reduced habitat. Mitchell, A.H. and Tilson, R.L. (1986) Restoring the balance: traditional hunting and All of the Mentawai primates are primate conservation in the Mentawai Islands, threatened with extinction. However, in Indonesia. Pp. 249-260 in J. Else and P. Lee, eds., Primate Ecology and Conservation. the Pagai Islands, education programs University of Cambridge Press, Cambridge. and a move away from hunting in many Tenaza, R.R. (1975) Territory and monogamy villages are reducing the actual rate of among Kloss’ gibbons in Siberut Island, hunting primates for food. It is the Indonesia. Folia Primatologica 24:60-80. macaques who continue to be highly at 3 Tenaza, R.R. (1987) Studies of primates and group size, forest type and vertical their habitats in the Pagai Islands, Indonesia. stratification were recorded for contacts. Primate Conservation 8:104-110. Information on the type and degree of Tenaza, R.R. (1989) Primates on a precarious threat to each primate taxa also was limb. Animal Kingdom 92(6):26-37. gathered. The results of these surveys Tilson, R.L. (1980) Monogamous Mating will form the basis for recommendations Systems of Gibbons and Langurs in the Mentawai Islands. Unpublished Ph.D. for new reserves as well as suggest dissertation, University of California, Davis. appropriate conservation action for Tilson, R.L. and Tenaza, R.R. (1982) existing areas. Interspecific spacing between gibbons (Hylobatea klossi) and langurs (Presbytia Methods potenziani) on Siberut Island, Indonesia. American Journal of Primatology 2:355- Survey localities were determined 361. through discussions with local scientists Whitten, A.J. (1982) The Gibbons of and Ministry of Forestry (MOF) officials Siberut. J.M. Dent, London. and reviews of recent vegetation maps, Whitten, AJ. and Whitten, J.E.J. (1982) aerial photographs and satellite imagery. Preliminary observations of the Mentawai macaque on Siberut Island, Indonesia. The resulting surveys were concentrated International Journal of Primatology in areas where live animals were known 3:445-459. to be sold in markets and where stuffed Wilson, C.C. and Wilson, W.L. (1976) doucs were for sale to tourists, on the Behavioral and morphological variation among borders of ranges and in locations for primate populations in Sumatra. Yearbook of which there were few or no reports. Physical Anthropology 20:207-233. During this first phase of distribution World Wildlife Fund (1980) Saving Siberut: surveys, existing trails were utilized A Conservation Master Plan. WWF, because of the possibility of contacting Switzerland. undetonated munitions. The number of encounters with douc DISTRIBUTION AND langur groups or individuals was CONSERVATION STATUS OF recorded. Following this, the distance to the center of the group was measured. DOUC LANGURS IN VIETNAM This was then calibrated with line transects to give a semiquantitative Lois K. Lippold method of sampling abundance (see Director, Douc Langur Project Brockelman and Ali, 1987). Whenever a Department of Anthropology primate was encountered, the time of San Diego State University observation and location were noted on a San Diego, CA 91282-4443 USA reserve map. The number of individuals, Introduction their sex and an estimation of each individual’s age also were recorded. This Four seasons were spent during 1994- was followed by a detailed description of 1995 surveying national parks, nature the face and coat coloration of adults of reserves and local forests in Vietnam to both sexes and of infants.