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Forest (and) primates: Conservation and ecology of the endemic primates of Java andBorneo

Nijman, V.

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Citation for published version (APA):Nijman, V. (2001). Forest (and) primates: Conservation and ecology of the endemic primates of Java andBorneo. Wageningen: Tropenbos International.

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Download date: 20 Aug 2019

Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic Primates

CHAPTERR 12

RE-ASSESSMENTT OF IUCN CONSERVATION STATUS OF THEE ENDEMIC PRIMATES OF JAVA AND BORNEO

ABSTRACT T

AA re-assessment of the IUCN status of the endemic primates of Java and Borneo was madee on the basis of a study from 1994-2001 and additional data from the literature. Fivee (or six) of the nine (or ten) endemics have their current status changed. Fuscous leaff monkey Presbytis frederica is currently classed as Data Deficient, but the speciess is here synonymised with grizzled leaf monkey P. comata. This species is currentlyy classed as Endangered and this status remains unchanged in the re-assessment.. Bornean leaf monkey P. hosei and Bornean gibbon Hylobates muelleri aree currently both classed as Lower Risk but on the basis of a sharp reduction of availablee habitat aggravated by hunting, both species are more appropriately classed ass Vulnerable. The white-fronted leaf monkey Presbytis frontata is currently classed ass data Deficient, but on the basis of low population densities over the greater part of itss range, and the sharp reduction of its lowland forest habitat it is classed as Vulnerable.. The proboscis monkey Nasalis larvatus is currently classed as Vulnerable,, but given a sharp reduction in available habitat and inadequate protectionn inside reserves, it is more appropriately classed as Endangered. Finally, thee Javan gibbon Hylobates moloch is currently classed as Critically Endangered, butt given a less dramatic decrease of remaining forest on Java as suggested, and the findingg of significant populations in Central Java, the species is more appropriately classedd as Endangered.

RINGKASAN N

Peninjauann kembali mengenai status konservasi menurut IUCN dari primata endemikk di Jawa dan Kalimantan: Peninjauan kembali kami buat mengenai status IUCNN dari primata endemik di Jawa dan Kalimantan berdasarkan hasil sebuah penelitianlapangann dan survai pada tahun 1994-2001 ditambah data pustaka. Lima (atauu enam) dari sembilan (atau sepuluh) jenis kera telah berubah status konservasinyaa saat ini. Rekrakan Presbytis fredericae saat ini diklasifikasi sebagai Kurangg Data, tetapi jenis ini dianggap kami sejenis dengan Surili P. comata. Jenis inii dianggap Genting saat ini, dan status ini tidak berubah pada tinjauan kembali kami.. Baik Bangat P. hosei maupun Kelawat Hylobates muelleri saat ini diklasifikasii Berisiko Rendah, tetapi kedua jenis ini lebih tetap diklasifikasi sebagai Rentan,, berdasarkan penyusutan drastis dari habitat yang ada, yang diperburuk oleh pemburuan.. Lutung dahi putih Presbytis frontata saat ini diklasifikasi sebagai

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Kurangg Data. Tetapi statusnya kami anggap sebagai Rentan, berdasarkan kepadatan rendahh di bagian terbesar wilayah penyebarannya. Bekantan Nasalis larvatus adalah satuu jenis saat ini diklasifikasi Rentan tapi terbatas pada kantung-kantung terakhir darii hutna tropis dataran di pingir sungai dan hutan bakau, lebih tetap diklasifikasi bagaibagai Genting. Terakhirnya, Owa Jawa H. moloch adalah satu jenis diklasifikasi Kriti ss tetapi kerena masih ada beberapa populasi yang cukup besar di Jawa Barat dann Jawa Tengah, lebih tetap diklasifikasi bagai Genting.

INTRODUCTION N

Inn the following section a re-assessment of the IUCN conservation status of the endemicc primates of Java and Borneo is presented. It is based on data presented in thee previous chapters of this thesis, additional and as yet unpublished results from thee study, and published data. Firstly, for each species its legislative status is given, i.e.. whether or not it is protected by Indonesian and / or Malaysian law. When the speciess is included on Appendix I or II of the Convention on International Trade in Endangeredd Species (CITES) this is indicated. Secondly, its present IUCN listing (basedd on Eudey, 1996/1997) is given with the criteria according to which it is includedd in that particular category. This is followed by the suggested IUCN listing andd its criteria. Finally, the justification of the changes (if any) are presented.

RESULTSS AND DISCUSSION

Grizzledd leaf monkey Presbytis comata LegislativeLegislative status: Protected by Indonesian Law as Presbytis aygula (Surat Keputusann Menteri Pertanian No 247/Kpts/Um/4/1979, Undang-undang No. 5 / 1990,, Surat Keputusan Mentri Kehutanan No 301/KPT-1171991 and No. 882/KPT-11/1992).. Included on Appendix II of the Convention on International Trade in Endangeredd Species (CITES).

PresentPresent IUCN status: Endangered based on criteria: AA 1(c): A reduction of at least 50% over the last three generations (<35 years -inferredd from life history data of colobine monkeys in Rowe [1996]) based on a declinee in area of occupancy, extent of occurrence, and / or quality of habitat. C2(a):: Population estimated to number less than 2500 mature individuals and a continuingg decline, observed, projected, or inferred, in numbers of mature individualss and population structure in the form of severely fragmented sub-populationss (i.e. no sub-population estimated to contain more than 250 mature individuals). .

SuggestedSuggested IUCN status: Endangered based on criterion Al(c).

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Justification:Justification: The distribution range is larger than previously assumed, with substantiall populations occurring in central Java (chapters 6 and 8). No large changess in the extent of habitat have occurred as compared to previous assessment. Thee total population is significantly larger than assumed under C2(a). The most recentt estimate of 2285 individuals as obtained during a PHVA (Supriatna et al., 1994)) is unrealistic for at least four reasons: (i)) It is based on an incomplete data set (only seven of 33 areas known to be

inhabitedd by the species were included in the analysis); (ii )) It is based on wrong assumptions. The species would prefer a narrow

altitudinall zone between 1200 and 1800 m a.s.1., rarely occurring below 1200 mm a.s.1. In fact it occurs from sea level to 2500 m a.s.1., most likely attaining its highestt densities in the lowlands (Nijman, 1997; chapter 6);

(iii )) During the data compiling process there must have been confusion between the twoo Javan leaf monkeys. Grizzled leaf monkey would have a preference for ecotones,, edges and riverborders, and would not occur inside the core of a forestedd area. This description in all likelihood refers to ebony leaf monkey TrachypithecusTrachypithecus auratus and certainly not grizzled leaf monkey. During the PHVAA meeting the two endemic leaf monkey were often mixed up. In fact the participantss were invited to attend a meeting on the Javan gibbon and silver leaff monkey Trachypithecus auratus [=ebony leaf monkey] (Anonymous, 1994)) and not a meeting on Javan gibbons and grizzled leaf monkey Presbytis comata.comata. The handbook with background information (Anonymous 1994) even explainss that the silver leaf monkey consists of three subspecies, again suggestingg the workshop deals with Trachypithecus auratus of which there are threee subspecies as opposed to Presbytis comata of which two subspecies have beenn described. In this same handbook a summary is given of the diet and feedingg behaviour of ebony leaf monkeys, again suggesting that the meeting dealss with ebony leaf monkey. Finally, in the proceedings of the workshop (Supriatnaa et al., 1994) photographs of ebony leaf monkeys are included but nott of grizzled leaf monkey.

(iv)) Under-estimation of population densities. Supriatna et al. (1994) used a populationn density of four individuals km" corresponding with one group per 1.755 km2. Indeed in a number of areas the species is known to be rare (e.g., Ujungg Kulon) or to show a patchy distribution within reserves (e.g., Tukung-Gede).. However, data from Table 12.1 and comparisons with data from other PresbytisPresbytis species (Oates et al., 1994) suggests densities between 10 to 20 individualss km'2 to be more typical.

Dataa presented in table 12.1 also suggest large differences between the two methods employedd for censussing this primate. Density estimates obtained with the line transectt method are typically a fifth of those obtained with the range mapping method.. Reported group sizes for grizzled leaf monkeys from line transects (average 4.00 individuals: Sugarjito et al., 1997; 4.8 individuals: Sugarjito & Sinaga, 1999; 2.0 individuals:: Gurmaya et al., 1995; but 7.0: Nijman & van Balen, 1997) are also

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generallyy smaller than reported from range mapping studies (average: 4.8 individuals:: Harjanti, 1996; 5.8 and 6.0 individuals: Ruhiyat, 1991: 7.0 individuals: Sujatnika,, 1992). In all likelihood the elusive nature of the species makes it difficult too detect, leading to an under-estimate of true densities during line transect surveys. Thee range mapping method invariably has been employed in ecological studies and hencee the study areas were selected as to contain a fair number of grizzled leaf monkeyy groups, precluding extrapolation to densities over large areas.

Tablee 12.1 Estimates of densities of grizzled leaf monkey Presbytis comata in Java

Locality y

Ujungg Kulon Mt.. Tukung Gede Mts.. Halimun Mts.. Halimun Mts.. Halimun Mts.. Halimun Mts.. Halimun Mts.. Halimun Mt.. Gede Mt.. Patuha Kamojang g Patenggang g Mts.. Dieng

Altitude e (masl) ) 0*400 0 40-400 0 600-1200 0 1200-1750 0 600-1200 0 1200-1400 0 1400-1750 0 900-1200 0 1300-1500 0 2000-2200 0 1400-1600 0 1600-1800 0 650-850 0

Density y (ind.. km"2) 1.3t t 4.3TT T 8.2TTT T 2.1 1 2.6 6 04 4 1.4 4 4-5 5 25 5 10-15 5 10-12 2 35-36# # 28 8

Method d

Line-transect t line-transect t line-transect t line-transect t linee transect linee transect linee transect ~ ~ mapping g mapping g mapping g mapping g line-transect t

Source e

Gurmayaa et al., 1995 Melishh & Dirgayusa, 1996 Sugarjitoo etal., 1997 Sugarjitoo et al., 1997 Sugarjitoo & Si naga, 1999 Sugarjitoo & Sinaga, 1999 Sugarjitoo & Sinaga, 1999 Maitarr in Supriatna et al., 1994 Sujatnika,, 1992; pers. comm. Harjanti,, 1996 Ruhiyat,, 1983; 1991 Ruhiyat,, 1983; 1991 Nijmann & van Balen, 1998

TT T

TTT T

Estimatee might be rather low as parts of the reserve that are known not to be inhabited by grizzled leaff monkeys were included in the survey (K.J. Gurmaya, pers. comm); Melish & Dirgayusa (1996)) report that, according to park wardens, the population has decreased over the last two decades. . Line-transectt was situated along the forest fringe and densities in forest interior may differ (Melish && Dirgayusa, 1996). Thee two studies by Sugarjito et al. (1997) and Sugarjito & Sinaga (1999) seem to be based on the samee data set, yet density estimates from the second study are about a third of the first. The reason forr this discrepancy is unknown. Ruhiyatt (1991) reports that the relatively high density in Patenggang was at least partially caused byy previous logging operations and/or the recent opening of parts of the forest for tea cultivation, bothh limiting the amount of forest available.

Borneann leaf monkey Presbytis hosei LegislativeLegislative status: Not protected by Indonesian Law (although there is room for speculationn as P. comata is listed as P. aygula; P. hosei was formerly considered to bee included in this taxon), not protected by Malaysian Law (Sarawak and Sabah); legislativee status in Brunei not known. Included on Appendix II of the Convention onn International Trade in Endangered Species (CITES).

PresentPresent IUCN status: Lower Risk 3 (least concern).

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SuggestedSuggested IUCN status: Vulnerable based on criterion: AA 1(c): A reduction of at least 20% over the last three generations (<35 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. .

Justification:Justification: The species has a restricted range distributed over three countries. It is inadequatelyy included in the protected area net work, although a substantial populationn is present in the Kayan Mentarang National Park. The species is common inn certain areas (e.g., Kayan Mentarang National Park: Nijman 1997, S. Wulfraat, pers.. comm.; Dent Peninsula, Sabah: Davies & Payne 1982), but rare in others (Sepilok:: Bennett & Davies 1994). Apparently it is especially rare in those areas wheree red leaf monkeys are common (Payne et al., 1985). Highest densities are reachedd in lowland rain forest (Davies & Payne 1982), a habitat that is becoming increasinglyy rare. The species is able to survive in disturbed forest (secondary forest, selectivelyy logged forest) but at significantly lower densities (Nijman 1997; Johns 1992). .

Thee species used to be common in the Kutai regions (Rodman 1978) but has lostt most of its habitat due to the forest fires (Suzuki, 1994) and illegal logging. A surveyy in 2000 failed to find a single individual in the eastern region of the Kutai Nationall Park (V. Nijman unp. data). All of its habitat outside the protected area networkk in Kalimantan has been earmarked for conversion or has been handed out as concession. .

Throughoutt its range it is hunted for food and for its valued bezoar stones (viscerall concretions used in traditional medicine and sometimes found in this and otherr Presbytis species). Hunting is often associated with inland settlements, the timberr industry and the demand for bezoar stones. In Sarawak the three leaf monkey speciess {Presbytis frontata, P. rubicunda, and P. hosei) account for at least one percentt of all mammals hunted, which may account for some 20,000 monkeys annuallyy (Bennett et al., 1987). Hunting for bezoar stones seems to be concentrated too restricted areas (Nijman 1997; Pfeffer 1958), but can have a severe impact on locall populations. The demand for bezoar stones can lead to excesses such as the killin gg of dozens of Bornean leaf monkeys near the southern border of the Kayan Mentarangg National Park by adding poison to sungans (salt-water springs) (A. Rachmat,, pers. comm.).

Fuscouss leaf monkey Presbytis fredericae LegislativeLegislative status: Protected by Indonesian law as P. aygula (see under P. comata). Includedd under P. comata on Appendix II of the Convention on International Trade inn Endangered Species (CITES).

PresentPresent IUCN status: Data Deficient SuggestedSuggested IUCN status: Endangered as Presbytis comata

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Justification'.Justification'. Presbytis fredericae is synonymised with Presbytis comata (chapter 5) andd as such no IUCN status is justified. Populations of P. comata in the eastern part off its range are all found in unprotected forest areas.

White-frontedd leaf monkey Presbytis frontata LegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan Menteri Pertanian Noo 247/Kpts/Um/4/1979, Undang-undang No. 5 / 1990, Surat Keputusan Mentri Kehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Not protected by Malaysiann Law (Wild Life Protection Ordinance 1958). Included on Appendix II of thee Convention on International Trade in Endangered Species (CITES).

PresentPresent IUCN status: Data Deficient SuggestedSuggested IUCN status: Vulnerable based on criterion:

AA 1(c): A reduction of at least 20% over the last three generations (<35 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. .

Justification:Justification: The species' distribution range is larger than previously assumed (chapterr 11) and the species is not restricted to low altitude forest below 300 m a.s.1. ass suggested by Medway (1970). It is present in large parts of Borneo but probably confinedd to lowland forest (<1000 m a.s.1.). White-fronted leaf monkey attains its highestt density in the central part of its range from where it was previously assumed too be absent (e.g., Oates et al., 1994; MacKinnon, 1984; Rowe, 1996; see Table 12.2). .

Tablee 12.2 Densities of white-fronted leaf monkey Presbytis frontata at different localities in Borneo

Locality y

Lanjak-Entimauu south central l north h

BB a tang Ai Kapuas-Mahakam m Kutaii National Park Berau u Gnn Palung Kembera

Selinsing g Sungaii Wain

Bann to Ulu Longg Bia Bukitt Suharto Betungg Kerihun

Density y groupss km"2

2.10 0 1.94 4 1.20 0 1.16 6 12.5 5 0.06 6 0.2-0.7 7 0.4-0.5 5 0.4-0.5 5 0.3-0.4 4

Indicationn of density

rare e rare e rare e common n

Individuals s km2 2

8.88 8 8.20 0 5.09 9 --43.7 7 0.06 6 1.2-1.7 7 1.9-2.4 4 0.4-0.5 5 1.1-1.4 4

Group p size e 4.23 3

--3-4 4 1 1 2-6 6 5 5 1 1 3-5 5

2-3 3 3-4 4

----

Reference e

Blouch,Blouch, 1997

Meredith,, 1993 in Blouch, 1997 Istiadii etal., 1994 Suzuki,, 1992 Yanuaretal.,, 1995 J.M.. Lammertink, in litt.

V.. Nijman, unp. data

Mather,, 1994 V.. Nijman, unp. data Yasumaa & Ahkodra, 1990 J.K.. Gurmaya, pers. comm.

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Thee density estimate obtained by Istiadi et al. (1994) is considerably higher than fromm any other region. This might be due to methodological differences, but their resultss clearly indicate that the species is common in the Kapuas-Mahakam region (cf.. information from local inhabitants of the S. Rata region, V. Nijman, unp. data). Centrall populations are adequately included in the protected area network as significantt population are present in the Lanjak Entimau, Batang Ai, and Betung Kerihunn reserves (Blouch, 1997; J.K. Gurmaya, pers. comm.), but eastern and westernn populations are largely located outside reserves. In West Kalimantan white-frontedd leaf monkey is probably patchy distributed with (isolated?) populations near Gunungg Palung National Park. In East Kalimantan it is probably present throughout thee province, but only locally and in small numbers. Given the species' occurrence at (very)) low population densities over a fairly large area, it might be nomadic (Medwayy 1970), at least in parts of its range. The species is hunted for bezoar stones,, whereas hunting for food is widespread throughout the interior of Borneo.

Redd leaf monkey Presbytis rubicunda LegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan Menteri Pertanian Noo 90/Kpts/Um/2/1977, Undang-undang No. 5 / 1990, Surat Keputusan Mentri Kehutanann No 301/Kpts-II/1991, and No. 882/Kpts-II/1992). Not protected by Malaysiann Law, legislative status in Brunei not known. Included on Appendix II of thee Convention on International Trade in Endangered Species (CITES).

PresentPresent IUCN status: Lower risk 3 (least concern) SuggestedSuggested IUCN status: Lower risk 3 (least concern)

Justification:Justification: The species is endemic to Borneo and Karimata Island, off the west coastt of Borneo. On Karimata the species is common (Yanuar et al., 1993). It is the mostt widespread of the Bornean colobines, occurring throughout most of the lowlands,, hills, and mountains (Yanuar et al., 1995). The species occurs in secondaryy forest albeit in lower numbers. It occurs mainly below 1500 m a.s.1. (MacKinnon,, 1987), although records from Mt Kinabalu suggest occurrence below 20000 m a.s.1. Red leaf monkeys are present in most of the larger reserves and the presentt protected area network seems to be adequate for the species. As other PresbytisPresbytis species it is frequently hunted in the interior, both for its bezoar stones and forr food.

Ebonyy leaf monkey Trachypithecus auratus LegislativeLegislative status: Protected by Indonesian Law (Surat Keputusan Menteri Kehutanann dan Perkebunan No 733/Kpts-II/1999). Included on Appendix II of the Conventionn on International Trade in Endangered Species (CITES).

ForestForest (and) Primates

PresentPresent WCN status: Vulnerable based on criteria: Al(c) :: A reduction of at least 20% over the last three generations (<35 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. . B2(c)(d):: Extent of occurrence estimated to be less than 20,000 km2 or area of occupancyy estimated to be less than 2000 km2, and estimates indicating a continuingg decline, inferred, observed or projected, in area, extent and/or quality off habitat, and number of locations or sub-populations.

SuggestedSuggested WCN status: Vulnerable based on criterion Al(c).

Justification:Justification: Ebony leaf monkeys show a restricted distribution range with a large numberr of isolated fragments on three islands; the extent of occurrence as estimated underr B2 is a considerable under-estimate. Although the species is quite tolerable to aa certain degree of habitat disturbance and can be found in a large variety of forest types,, including man-made, it is dependent on forest cover of some sort. In plantationss it is normally restricted to those parts where more natural forest (e.g., alongg river stretches) is still present (Nijman, 2000; chapter 7). Probably most safe inn mountain habitats, but population densities are lower at higher altitudes than in lowlandd forests.

Locall populations in mangrove areas have gone extinct (Supriatna et al., 1988) or aree inferred to have become extinct on the basis of total destruction of habitat (Nijmann 2000; chapter 7). Some small isolated populations are probably not viable inn the long run. Overall the species' habitat is severely fragmented and this greatly limitss dispersal between populations. The species is not present on the Kangean islandss as has been suggested (e.g., de Iongh et al., 1982; Bergmans & van Bree 1986).. Ebony leaf monkeys are well included in the present protected area network (itt is present in most of the larger protected areas on Java, Bali, and Lombok), althoughh active protection of the species in these areas or active protection of their habitatt is often absent.

Tradee may turn out to be an increasing problem, as the species is heavily traded onn Java. For the province of east Java alone it has been estimated that some 227 individualss are traded per month (Anonymous 2000). Ebony leaf monkeys are often onee of the most common primate species found on bird markets. The erythristic pelagee morph is more expensive than the more common melanic pelage morph. Tradee of ebony leaf monkeys occurs over long distances, and the erythristic pelage morphh is commonly seen on West Javan bird markets (Nijman 2000; chapter 7).

Probosciss monkey Nasalis larvatus LegislativeLegislative status: Protected by Indonesian Law (Peraturan Perlindungan Binatang Liarr 1931 No. 266, Undang-undang No. 5 / 1990, Surat Keputusan Mentri Kehutanann No 301/Kpts-II/1991, and No. 882/Kpts-II/1992). Protected by Malaysiann Law (Wild Lif e Protection Ordinance 1958), legislative status in Brunei

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nott known. Included on Appendix II of the Convention on International Trade in Endangeredd Species (CITES).

PresentPresent 1UCN status: Vulnerable based on criteria: A2(c):: A reduction of at least 20% projected or suspected to be met within the nextt three generations (<45 years) based on a decline in area of occupancy, extentt of occurrence and / or quality of habitat. C2(a):: Population estimated to number less than 250 mature individuals and a continuingg decline, observed, projected, or inferred, in numbers of mature individualss and population structure in the form of severely fragmented sub-populationss (i.e. no sub-population estimated to contain more than 250 mature individuals). .

SuggestedSuggested IUCN status: Endangered based on criterion: AA 1(c): A reduction of at least 50% over the last three generations (<45 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. .

Justification:Justification: Although the distribution range of the species is larger than previously assumed,, with populations occurring far inland, it is under severe threat from huntingg and habitat loss. Many inland populations are already severely diminished in sizee and number and it is expected that many local populations have become extinct. Huntingg is widespread in the interior, and with many people moving from the interiorr to coastal areas as well as people from areas with few restrictions to hunting primatess (e.g., Sulawesi, Sumatra) migrating to Borneo, hunting in coastal areas is increasing. .

Probosciss monkey probably has the greatest proportion of its remaining habitat destroyedd by the 1997 forest fires of any primate species in Kalimantan (Yeager & Frederikssonn 1998): fire hot spots during the 1997-1998 forest fires were more likely too occur near rivers (Fuller & Fulk 1998). The species is restricted to forest in low-lyingg areas (mostly below 300 m a.s.1.) which is also most favoured by people for logging,, cultivation, and village settlement.

Thee protected area network is far from adequate. In five of the six protected areass in Indonesia where the species is represented by at least several hundred individuals,, populations are declining (Meijaard & Nijman 2000, chapter 9). The largestt population of the species occurs in Kalimantan where active species managementt or active management of proboscis monkey's habitat is inadequate. In Sabah,, the only area where the species still seems to be common is the Lower Kinabatangann (Boonratana 2000), whereas it occurs in a few areas of Sarawak where itt is generally rare (Bennett et al., 1987). A small isolated population occurs in Brunei. .

Thee suggestion that proboscis monkey might be better classed as endangered as opposedd to vulnerable has also been made by Eudey (1996/1997).

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Javann gibbon Hylobates moloch LegislativeLegislative status: Protected by Indonesian Law (Peraturan Perlindungan Binatang Liarr 1931 No. 266, Undang-undang No. 5 / 1990, Surat Keputusan Mentri Kehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Included on Appendix I off the Convention on International Trade in Endangered Species (CITES).

PresentPresent IUCN status: Critically endangered based on criteria: AA 1(c): A reduction of at least 80% over the last three generations (45 years: Supriatnaa et al., 1994) based on a decline in area of occupancy, extent of occurrencee and / or quality of habitat. C2(a):: Population estimated to number less than 250 mature individuals and a continuingg decline, observed, projected, or inferred, in numbers of mature individualss and severely fragmented population structure (i.e. no sub-population estimatedd to contain more than 50 mature individuals).

SuggestedSuggested IUCN status: Endangered based on criterion: Al(c) :: A reduction of at least 50% over the last three generations (45 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. .

Justification:Justification: The distribution range is larger than previously assumed (Nijman 1995,, Nijman & Sözer 1995; Nijman & van Balen 1997). The inferred decline of 2400-79000 gibbons in 1978 to 400 gibbons in 1994 (Supriatna et al., 1994) is largely basedd on differences in methodology used, i.e. extrapolation based on geographic areaa inhabited and density at different altitudinal zones (Kappeler 1981, 1984) vs. numberr of individuals actually observed in a few areas (Supriatna et al., 1994). I assumee that this inferred decline was the main reason for listing the species as criticallyy endangered. The lower estimate has been questioned (Asquith 1995, 2001), andd data from the present study makes it increasingly unlikely to be held true. As an example,, the central Javan populations would consist of 17 individuals (confined to Gnn Slamet) according to Supriatna et al. (1994), whereas probably over 800 individualss are present.

Tablee 12.3 lists the number of gibbons present on Java, broken down to 15 forest areass that are inhabited by more than 50-100 gibbons. From this listing it becomes apparentt that the total number of gibbons in Java is more likely to be in the order of 40000 individuals, i.e. an order of magnitude larger than previously estimated (Supriatnaa et al., 1994). Estimates of the number of gibbons in one area (Halimun nationall park) have remained fairly constant over the last 20 years, despite various reportss on the loss of habitat at both the lower regions of this park as from the enclavee in the center of the park (Whitten et al., 1996). Thus, Kappeler (1981) estimatedd the population of the park to be between 600-1800 individuals in 1978, Kooll (1992) at 852-1320 individuals in 1989, Asquith et al. (1995) at 870 in 1994, andd finally, Sugarjito & Sinaga (1999) at 864-936 individuals in 1997.

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TableTable 12.3 Estimated number of Javan gibbons Hylobates moloch present in Java

Area a

Ujungg Kulon (Gn Honje & Tanjung Tereleng) ) Gnn Halimun Gnn Salak Telagaa Warna - Megamendung Gedee Pangrango Sangabuana a Burangrangg - Tangkuban Perahu Gnn Simpang Gnn Tilu Gnn Papandayan Gnn Wayang Peg.. Pembarisan Gnn Slamet Gnn Lawet - Cupu-Simembut- Jaran Peg.. Dieng Totall population

Status' '

NP P

NP P Unp. . NRR / unp. NP P Unp. . NRR / unp. NR R NR R NR R Unp. . Unp. . Unp. . Unp. . Unp. .

Alt.. range

0-480 0-480

400-1929 9 800-2210 0 500-1600 0 500-3019 9 250-1280 0 900-2081 1 400-1816 6 900-2434 4 700-2622 2 500-1830 0 300-1351 1 700-3428 8 700-1100 0 300-2565 5

Forestt area2

85 5

270 0 70 0 30 0 50 0 50 0 40 0 140 0 30 0 120 0 85 5 120 0 40 0 20-30 0 120-135 5 1270-1295 5

Total l number r

560 0

850-1320 0 140 0 >50? ? 100 0 100 0 >50? ? 600 0 100 0 250 0 300 0 >50? ? 100? ? >50? ? 519-577 7 4019-4397 7

Numberr of adults3 3

339 9

515-800 0 85 5 >30? ? 61 1 61 1 >30? ? 364 4 61 1 152 2 182 2 >30? ? 61? ? >30? ? 315-350 0 2436-2665 5

Source e

a,, b

a,, c, d a a b b b,, e a,, b b b a a a a a a a a b,, f b,, f b b b,g g

Status:: NP= national park (taman nasional); NR= strict nature reserve (cagar alam); unp. = not protectedd as conservation forest: smaller sections might be protected as strict nature reserve. Habitatt is the approximately available habitat inhabited by gibbons. Forest above 1500 m a.s.1. is nott included. Numberr of adults is based on an average group size of 3.3 individuals, of which two are adult; floaterss are not included in any of the above estimates. aa = Asquith et al. 1995; b = = Nijman unp. data; c = Kool 1992; d = Sugarjito et al. 1997; e = Harris 1996;; f = Nijman 1995; g = = Nijman & Van Balen 1997.

Thee new total population estimate is unlikely to be an over-estimate, as overall a conservativee population density of less than one gibbon group km"2 has been used (i.e.. 4000 gibbons in 1300 km2 forest). Furthermore, the species is known from at leastt 11 other (mostly small and sometimes fragmented) forest areas (viz. Gn Jayanti-Tangkubann Perahu, Lengkong, Gn Porang, Cisolok, Bojongpicung, Pasir Susuru,, Gn Malang, Gn Halu, Leuweung Sancang, Gn Masegit-Kareumbi, Gn Manglayang,, and possibly Gn Sawal and Gn Ciremai), from which few data on forestt size or number of gibbons present are currently available.

Asquithh et al. (1995) reported the apparent extinction of nine local gibbon populations,, mostly due to loss of habitat. Two of these forest areas (Telaga Warna andd Tangkuban Perahu-Burangrang) in fact are still inhabited by gibbons (pers. observ.).. Given the overall loss of forest in west and central Java, many more gibbon populationss have undoubtedly suffered from habitat loss over the last few decades. Largee scale deforestation on Java dates back to the first half of the 19th century, whenn the Dutch colonial government imposed the so-called 'cultuurstelsel' which forcedd farmers to grow cash crops on communal grounds (often forest). During the followingg 100 years, large areas of forest were lost and many became fragmented. Overr the last 50 years or so, however, large scale deforestation has slowed down (seee e.g., Whitten et al., 1996). Hence, there does not seem to be a justification for

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inferringg a loss of 80% of the Javan gibbon population (or their habitat) over the last 500 years as assumed under criterion A 1(c).

Likewise,, there seem to be at least eleven forest areas with an estimated populationn of a 100 gibbons (corresponding to at least 60 mature individuals) or more,, and four areas with over 500 gibbons each. Listing the Javan gibbon as criticallyy endangered under criterion C2(a) hence becomes questionable.

Borneann gibbon Hylobates muelleri LegislativeLegislative status: Protected by Indonesian Law (Peraturan Perlindungan Binatang Liarr 1931 No. 266 and Undang-undang No. 5 / 1990 and Surat Keputusan Mentri Kehutanann No 301/Kpts-II/1991 and No. 882/Kpts-II/1992). Protected by Malaysian Laww (Wild Life Protection Ordinance 1958), but specified therein by invalid scientificc name, which may subvert prosecution. Legislative status in Brunei not known.. Included on Appendix I of the Convention on International Trade in Endangeredd Species (CITES).

PresentPresent IUCN status: Lower Risk 2(near threatened) SuggestedSuggested IUCN status: Vulnerable based on criterion:

AA 1(c): A reduction of at least 20% over the last three generations (<45 years) basedd on a decline in area of occupancy, extent of occurrence and / or quality of habitat. .

Justification:Justification: Bornean gibbon is endemic to the area north of the Kapuas River and Eastt of the Barito River. Its range encompasses three countries. The species is confinedd to altitudes below 1250, and attains its highest density in the lowlands (Daviess & Payne 1982). Lowland forest is becoming increasingly rare on Borneo. Al ll of its habitat outside the protected area network in Kalimantan has been earmarkedd for conversion or has been handed out as concession. Bornean gibbons aree present in a number of large reserves in the island's interior (including Kayan Mentarang,, Lanjak Entimau, Batang Ai, Betung Kerihun), but formerly significant populationss in Kutai National Park and Bukit-Suharto have almost completely disappeared.. The species is able to survive in disturbed forest (secondary forest, selectivelyy logged forest) but at lower densities (Nijman 1997; Johns 1992). Large partss of its range have been negatively affected by the forest fires of the last decades, andd it is anticipated that parts of its remaining habitat will be lost with the next forest fires.fires. Burned-over forests offers little, if any, room for the species to survive. Throughoutt its range it is hunted for food; hunting often being associated with inlandd settlements and the timber industry.

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Re-AssessmentRe-Assessment oflUCN Conservation Status of the Endemic Primates

LEGISLATIVEE STATUS OF PRIMATES IN INDONESIA

Ass became clear from the above listing there is littl e consistency in the protective statuss of primates in Indonesia. Some of the species with a very restricted range withinn Indonesia, and often World-wide are not protected by law, whereas other, moree wide-ranging and common species, are protected. This even becomes more apparentt when all primates, and not just the ones endemic to Java and Borneo are included. .

Manyy primate species are identifiable by specialists only, often on characters likee vocalisation or minor differences in pelage characteristics. When prioritising whichh species deserves legal protection, this should explicitly taken into consideration.. This might be illustrated by the different Presbytis taxa that occur in Indonesia,, and their protective status. The leaf monkeys of Sumatra, Java and Borneoo occur in a great variety of colours from almost completely white to black, andd in all sorts of different pelage patterns. If we take a closer look at the grey-backedd leaf monkeys only, we end up with populations of at least five species, i.e. Sumatrann leaf monkey P. thomasi, southern populations of P. melalophos on Sumatra,, some populations of P. femoralis also on Sumatra, the western populations off P. comata on Java, and Bornean leaf monkey P. hosei. At present only P. thomasi andd P. comata are protected by Indonesian law, yet it will be very difficult to distinguishh the different taxa once encountered at a bird market or when in illegal captivity.. The same is true for the Trachypithecus leaf monkeys where T. auratus is protectedd but T. cristata is not, yet to the non-specialist both species may appear veryy similar.

Anotherr caveat in protecting primates in Java is the use of outdated nomenclaturee in the legislative literature. Primate taxonomy in Indonesia is a disciplinee in motion, and with the use of molecular systematics and other techniques, andd better understanding of evolutionary relationships between taxa, new taxa are beingg described regularly, and the geographic boundaries recognised between allopatricc species shift regularly.

Thesee difficulties in identifying and distinguishing protected from non-protectedd species, and changes in nomenclature, may, and indeed do, create a loop-holee for malevolent keepers and may promote illegal trade. The easiest solution to thiss problem is to protect either all primates, or protect primates by genus. The gibbonss are already included as such, thus all hylobats are protected by Indonesian laww (see above). This system can easily be adopted for the other primates are well. Thuss the different leaf monkeys, the proboscis monkey and the pig-tailed langur, can alll be protected as colobines. Indeed proposals as these have been submitted to the compilerss at the Workshop on Keeping Wild Protected Animals (Lokakarya Penanganann Satwa Liar Peliharaan yang Dilundungi) held in Bogor at 20-21 July 2000. .

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180 0