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Distribution, Population Structure, and Conservation ofLion-Tailed Macaques (Macaca silenus) in the AnaimalaiHills, Western Ghats, India
MEWA SINGH1*, MRIDULA SINGH1, M. ANANDA KUMAR1, H.N. KUMARA1,A.K. SHARMA1, AND W. KAUMANNS2
1Biopsychology Laboratory, University of Mysore, Mysore, India2Zoologischer Garten Koln, Koln, Germany
The lion-tailed macaque is an endangered species, and hence it isnecessary that the remaining populations in the rainforests ofthe Western Ghats, India, be located and their habitats assessedfor effective conservation. The Anaimalai Hills in the state of TamilNadu harbor 31 groups of lion-tailed macaques. However, the rainforestin these hills is highly fragmented. Since lion-tailed macaques aretypically arboreal, the groups have become isolated. Two large rain-forest complexes in these hills harbor 12 and seven groups, respect-ively, and the remaining 12 groups inhabit small, isolated forestfragments. Group size ranges from six to 53 individuals, with amean size of 16.3. In the small forest fragments, the standard deviation(SD) of group size was considerably higher than it was in the largerforest complexes. The disturbed fragments also had a higher variabilityin group size than the relatively undisturbed habitats. It is believedthat fragmentation may impede male migration. We suggest thatthe fragments be managed in such a way that male migration amonggroups can be facilitated to overcome the potential effects of isolation.Am. J. Primatol. 57:91–102, 2002. r 2002 Wiley-Liss, Inc.
Key words: lion-tailed macaque (Macaca silenus); Anaimalai Hills;Western Ghats; rainforest; fragments; conservation
INTRODUCTION
The lion-tailed macaque (Macaca silenus) is a critically endangered species.The biological significance accorded to this species is due to its primitiveevolutionary status among macaques [Fooden, 1982], typical arboreal habit,specialized feeding, low population densities, and low population turnover[Kumar, 1987]. For the effective management of such a species, it is essential
Contract grant sponsor: Ministry of Environment and Forests, Government of India; Contract grantsponsor: Indo-U.S. Primate Project, U.S. Fish and Wildlife Service; Contract grant sponsor:Volkswagen Foundation, Germany.
*Correspondence to: Mewa Singh, Biopsychology Laboratory, University of Mysore, Mysore 570006,India. E-mail: [email protected]
Received 25 February 2002; revision accepted 24 April 2002
DOI 10.1002/ajp.10037Published online in Wiley InterScience (www.interscience.wiley.com).
r 2002 Wiley-Liss, Inc.
American Journal of Primatology 57:91–102 (2002)
that remaining populations in the natural habitats be located (rather thanestimated) and the habitats assessed for their long-term viability.
The lion-tailed macaque inhabits evergreen rainforests in the Western Ghatshill ranges in the states of Karnataka, Tamil Nadu, and Kerala in southern India.The Western Ghats, which run north to south along the western coast of India,are divided into two regions by a gap of about 40 km in the mountains at Palghatin the state of Kerala. This gap divides the lion-tailed macaque populations intotwo groups: one inhabiting the rainforests north of the Palghat gap, and the otherinhabiting forests south of it. The total population of the species in the wild todayis estimated to be about 3,500–4,000 individuals [Kumar, 1995].
The lion-tailed macaque habitats and populations in the state of Karnatakawere assessed by Karanth [1985] through information based mostly on secondarysources. Recently, studies were initiated by Singh et al. [2000] to locate groupsof lion-tailed macaques and to assess their habitat conditions in certain parts ofKarnataka. A viable population of 10 groups was found in a 90-km2 rainforestin the Sringeri Forest Range in the Kuduremukh Proposed NationalPark [Singh et al., 2000]. In the states of Kerala and Tamil Nadu, threeregions of rainforest harbor viable populations of lion-tailed macaques:Silent Valley in Kerala, Kalakad-Mundanthurai, and the Anaimalai Hills inTamil Nadu. An assessment of lion-tailed macaque groups and their habitats inSilent Valley has been reported by Ramachandran and Joseph [2000].A population of 275 individuals in 14 groups inhabited the contiguous rainforestof the Silent Valley. Several reports have been published on lion-tailed macaquepopulations in the Anaimalai Hills [Kumar 1987; Kumar et al., 1995; Kumar et al.,in press; Singh et al., 1997a, b, 2001]. However, these reports provided data ononly a few groups [Kumar et al., 1995] or they dealt with many species, of whichlion-tailed macaque was only one of the species studied [Singh et al., 1997a, b].In this paper, we report the data collected during our uninterrupted researchover the past 7 years in these hills. We believe that we have now located allgroups of lion-tailed macaques in the Anaimalai Hills. For most of thegroups, habitat assessment has been done and demographic data has beenobtained. With such information, a comprehensive conservation plan can bedeveloped for this species in this region.
METHODS
The Anaimalai Hills lie between 1011300800 and 1013302700 N and 7614900200 and7712100700 E in the Western Ghats in the state of Tamil Nadu. A large part of thesehills (958 km2) lies in the Indira Gandhi Wildlife Sanctuary and National Park.The remaining area (about 180 km2) is owned by private companies and consistsof tea and coffee plantations (Fig. 1). A detailed description of the vegetationstructure, topographical features, and distribution of wild mammals in this regionis reported elsewhere [Kumar et al., in press].
The rainforest in these hills is restricted to a few central, but mostly westernparts of the hill ranges (Fig. 1). The western parts receive about 5,000 mm ofrainfall annually. A notable feature of the rainforest, however, is its fragmenta-tion. Inside the Indira Gandhi Wildlife Sanctuary and National Park there aretwo relatively large fragments of rainforest, each with an area of about 25–30 km2.One such complex is the Vargaliyar-Kuruvampalli-Panathiar-Manampalli-Shei-kalmudi region. The forests in this complex are connected to each other onlythrough narrow links of rainforest along hill slopes or valleys. The other complexis the Iyerpadi-Akkamalai-Itliar region. There are also several isolated and
92 / Singh et al.
Fig
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Lion-Tailed Macaque in Anaimalai Hills / 93
smaller (about 2–3 km2) fragments inside the sanctuary inhabited by lion-tailedmacaques, and these include Andiparai Shola, Waterfall Shola, Hindustan Shola,Anaigunthi Shola, Ramar Shola, and Sankaranakudi Shola (the word ‘‘shola’’refers to a patch of rainforest). The uninhabited fragments inside the sanctuaryinclude Karian Shola, Vandal Shola, and Periyakulam Shola. There are severalisolated rainforest fragments inhabited by lion-tailed macaques in private teagardens of the Valparai plateau, including Puthuthotam, Tata Estate, Pannimed,and Korangumudi.
The study includes the period from July 1994 to December 2001. Duringthese years, most of the fragments of rainforest were regularly visited, and groupsof lion-tailed macaques were identified. Groups were assigned identities on thebasis of location, group structure, and individual identifications. Group size andage-sex distribution were counted periodically (from at least twice a year in somegroups to twice a month in others) in several groups. Habitat assessment was alsocarried out during the course of this and other studies [Kumar et al., 1995; Kumaret al., in press; Menon & Poirier, 1996; Singh et al., 1998, 2001]. During thepresent study, the habitat disturbance index was developed as follows: the areawas classified as ‘‘maximum disturbance,’’ ‘‘medium disturbance,’’ or ‘‘relativelyundisturbed’’ if grazing by domestic livestock, human movement, and observa-tion/signs of logging were seen in more than 60%, in 10–60%, or in less than 10%visits, respectively. The age-sex classification in lion-tailed macaques as used inthe present study is shown in Table I. The age-sex determination was made on thebasis of body size, and reliability was determined on the basis of agreementamong at least three experienced observers.
Group values were compared using standard nonparametric statistics.Possible differences among groups in standard deviations (SDs) for valuescompared were assessed with the Fmax statistic (Lehner, 1998).
RESULTS
Locations and Distribution of Lion-Tailed Macaque Groups
Figure 1 presents the locations of lion-tailed macaque groups in theAnaimalai Hills. Table II presents detailed information on group identities,locations, and several features of their habitat. With the exceptions of KarianShola, Periyakulam Shola, and a few other natural rainforest fragments in theGrasshills region, all other patches of rainforest inside Indira Gandhi WildlifeSanctuary and National Park were inhabited by lion-tailed macaques. Weidentified 31 groups of lion-tailed macaques. Inside the Sanctuary, there were 26groups of monkeys. Of these 26 groups, 12 inhabited the Varagaliar complex ofrainforest in which their actual habitats were contiguous through at least narrow
TABLE I. Age-sex Classification in Lion-Tailed Macaques
Age-sex class Age range
Adult male 48 yearsSubadult male 4–8 yearsAdult female 46 yearsSubadult female 4–6 yearsJuvenile 1–4 yearsInfant o1 year
94 / Singh et al.
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Lion-Tailed Macaque in Anaimalai Hills / 95
river valleys or hill slopes. Seven groups inhabited another rainforest complex atIyerpadi-Akkamalai. Two rainforest fragments at Anaigunthi and Waterfallharbored two groups each. The remaining three groups inhabited three isolatedrainforest fragments at Andiparai Shola, Hindustan Shola and SankaranakudiShola. Five groups inhabited rainforest fragments in the privately-owned teagardens at Puthuthotam (two groups), Tata Estate (one group), KorangumudiEstate (one group), and Pannimed Estate (one group). The forest fragmentsinside the Sanctuary and in private areas ranged in size from less than 1 km2 toabout 4 km2. Inside the Sanctuary, the rainforest fragments were cut off fromeach other by hills covered with grasslands and non-dipterocarp stunted forests,patches of secondary deciduous forests or by commercial plantations of teak andeucalyptus. In the private areas, fragments were isolated by tea cultivation. Sincethe lion-tailed macaques are typically arboreal and obligatory rainforest dwellers,the movement among fragmented habitats is unlikely. Habitat disturbance, in theform of human and cattle movement and logging, was greater in the privatelyowned rainforest fragments. The lion-tailed macaques inhabited areas rangingfrom an altitude of 600 m asl at Varagaliar to 1800 m asl at Akkamalai. Thedensity of lion-tailed macaques in different habitats is presented in Table III.Whereas the density in the two large forest complexes at Varagaliar and Iyerpadi-Akkamalai was only 4.97 and 4.00 animals per km2, respectively, it wasconsiderably higher in most of the small fragments, reaching an abnormal highof 70 animals per km2 at Puthuthotam (Table III). Except at Puthuthotam whereno other primate species was present, all groups of lion-tailed macaque weresympatric with the Nilgiri langur (Semnopithecus johnii). Bonnet macaques(Macaca radiata radiata) were found seasonally in some habitats.
Population Structure of Lion-Tailed Macaque
Of the 31 groups present in these hills, we obtained a measure of group sizeon 23 groups and full age-sex composition for 16 groups (Table IV). The groupshad a mean size of 16.3 individuals, range 6–53 (Table IV). However, 65% of the
TABLE III. Density of Lion-Tailed Macaques in Different Habitats
Places No. of groups No. of animals Area in km2 Density per km2
Large complexesVaragaliyar 12 149 30 4.97Iyerpadi-Akkamalai 7 100 25 4.00
Two-group complexesWaterfall 2 30 3.5 8.57Anaigunthi 2 37 4 9.25Puthuthotam 2 70 1 70.00
Single-group fragmentsAndiparai 1 30 2.78 10.79Hindustan 1 6 3 2.00Tata 1 15 1 15.00Korangumudi 1 21 1 21.00Pannimed 1 8 1 8Sankaranakudi 1 ? 2.5 ?
96 / Singh et al.
groups had between 11 and 20 individuals and 82% of the groups had less than20 individuals. There was a mean of 2.13 adult males, 1.42 subadult males, 6.8adult females, 0.69 subadult females, 5.19 juveniles and 2.31 infants in thesegroups. The adult (subadults included) male to female ratio was 57:120 (1:2.11).The overall adult (subadults not included) to immature (less than 4 years in age)ratio was 143:120 (1:0.84). The adult female to immature ratio was 109:120(1:1.10). Table V presents the data on age-sex ratios of lion-tailed macaques from1996 to 2001. The population structure over the years has remained relativelyconstant.
TABLE IV. Age-Sex Composition in Groups of Lion-Tailed Macaques in Anaimalai Hills
Group Ad M Ad F SAd M SAd F Immature Total
And 4 11 2 1 12 30Wa1 2 7 1 1 7 18Ip1 2 4 1 1 4 12Ip2 3 5 1 0 7 16Ip3 2 7 3 0 6 18Pt1 3 16 3 2 29 53Pt2 3 6 1 0 7 17Tat 3 6 1 2 3 15Kor 1 8 2 0 10 21Ma1 2 5 2 1 5 15Ma2 2 4 0 2 0 8Pa1 1 3 2 0 6 12Va1 1 7 1 0 6 15Va2 2 6 2 0 6 16Kur 1 4 0 1 3 9An2 2 10 1 0 9 22Total 34 109 23 11 120 297Hin 6Wa2 12Ip4 14Akk 11Pan 8Ay1 12An1 15Total 375
TABLE V. Age-sex Ratios in Lion-Tailed Macaques in Anaimalai Hills From 1996 to 2001*
Year Group counted Ad M: Ad Fa Ad F: Immatureb Ad: Immature Ad F: Infant
1996 6 21:57 (1:2.71) 50:42 (1:0.84) 63:42 (1:0.67) 50:22 (1:0.44)1997 8 26:77 (1:2.96) 64:55 (1:0.86) 82:55 (1:0.67) 64:19 (1:0.30)1998 9 25:65 (1:2.60) 61:71 (1:1.16) 74:71 (1:1.04) 61:23 (1:0.38)1999 2 8:26 (1:3.25) 23:35 (1:1.52) 28:35 (1:1.25) 23:11 (1:0.48)2000 2 10:26 (1:2.60) 23:33 (1:1.43) 28:33 (1:1.18) 23:7 (1:0.30)2001 6 16:37 (1:2.31) 33:51 (1:1.55) 43:51 (1:1.19) 33:13 (1:0.39)
*Values in parentheses indicate ratio.aSubadults included. bImmatures include only juveniles and infants.Ad, Adult; M, Male; F, Female.
Lion-Tailed Macaque in Anaimalai Hills / 97
Statistical analysis [Lehner, 1998] of group size was also carried out inrelation to habitat types. Groups living in forest fragments had a mean group sizeof 19.73 (SD = 12.88; n = 1), while groups living in forest complexes had a meangroup size of 13.17 (SD = 3.01; n = 12) (Mann-Whitney U = 40; n = 23; P o0.11). Groups living in forest fragments ranged in size from six to 53 individualswhile groups living in forest complexes ranged in size from eight to 18 individuals(Fig. 2). The SD for group size in forest fragments was significantly greater thanthe SD for group size in forest complexes (Fmax = 18.3; n = 11,12; P o 0.01).Similarly, although the mean group size in private (22.83; n = 5) and government(14.50; n = 18) owned forests did not differ statistically (Mann-Whitney U =30.00; n = 23; P o 0.26), the SD in private forests (17.53) was significantly higherthan the SD in government-owned forests (5.47) (Fmax = 10.27; n = 5,18; P o0.01).
Analysis was also carried out for group size in relation to habitat disturbance(for disturbance index for each group, see Table II). Figure 3 presents the size ofeach group in maximum disturbance, medium disturbance, and relativelyundisturbed habitats. The mean group size was not significantly different amonggroups living in maximum disturbance (26.5, SD = 17.84; n = 4), mediumdisturbance (16.6, SD = 8.35; n = 5), and relatively undisturbed habitats (13.3,SD = 4.20; n = 14) (Kruskal-Wallis w2 = 4.53; df = 2; P o 0.10). The variance ingroup size in three habitats, however, was significantly different (Fmax = 18.15; n(largest vs. smallest variance) = 4.14; P o 0.01). The variation in group sizeincreased with increasing habitat disturbance.
DISCUSSION
The present study was restricted to the Anaimalai Hills region. However,these hills are contiguous with Parambikulam and Nelliampathy in the northwestand with the Chalakudi Hills in the southwest. There are sizable patches ofrainforest, most of them inhabited by lion-tailed macaques, in these adjoininghills. The whole ecosystem, therefore, is a potential region for the conservation oflion-tailed macaques. The Anaimalai Hills alone harbor a population of about 500lion-tailed macaques. However, as the results of the present study reveal, thispopulation is in fact divided into several populations inhabiting separate patchesof rainforest. The two populations inhabiting Iyerpadi-Akkamalai complex andVaragaliar complex appear to be biologically self sustainable with several groupsof lion-tailed macaque in each complex. The challenge for conservation isprimarily the management of lion-tailed macaque groups inhabiting smallfragments both inside the Sanctuary and in private tea gardens. The results ofthis study have revealed considerably higher densities of lion-tailed macaques insmall fragments as compared to the larger forest complexes. In Silent Valley[Ramachandran & Joseph, 2000] and Sringeri [Singh et al., 2000], which are alsolarge and contiguous complexes of rainforest, the densities of lion-tailedmacaques is very low as compared to the density in isolated fragments of theAnaimalai Hills. For a species with specialized and selective food habits, lowgrowth rates, low colonizing abilities, etc., the key to long-term conservation isthe maintenance of populations at a low but biologically viable populationdensities. In some fragments, such as Puthuthotam, where there is an abnormallyhigh density of 70 animals per km2, the monkeys are currently managing tosurvive by changing their food habits, including consumption of unpredictableand exotic items such as coffee and tea berries [Singh et al., 2001].
98 / Singh et al.
Group identity and number of individuals in each group in rainforest fragments
Group identity and number of individuals in each group in rainforest complexes
GROUP IDENTITY
Pt2AndAn2KorWa1Pt2TatAn1Wa2PanHin
NU
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GROUP IDENTITY
Ip3Ip2Va2Ma2Va1Ip4Ip1Pa1Ay1AkkKurMa2
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60
50
40
30
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0
Fig. 2. Identities and size of lion-tailed macaque groups in forest complexes and forest fragments.
Lion-Tailed Macaque in Anaimalai Hills / 99
Habitat fragmentation has shown a remarkable effect on the socionomic sexratio in lion-tailed macaque groups. In the Anaimalai Hills, there were 2.11 adultfemales per each adult male. On the other hand, the average number of adultfemales for each adult male was 5.6 in Silent Valley [Ramachandran & Joseph,2000] and 9.87 in Sringeri [Singh et al., 2000]. The rainforest in Silent Valley andSringeri is contiguous. The 14 groups of Silent Valley ranged in about 70 km2 ofrainforest, and the 10 groups of Sringeri had about 115 km2 of rainforestavailable. The result is a linear increase in the number of adult females relative toadult males with increased available area. Increased habitat size presumablyfacilitates adult male migrations. Natal males in fragmented forest do notdisperse from their natal group, whereas in larger and contiguous forests, thesemales tend to migrate. Migrating males may also be more prone to predationresulting in a higher ratio of adult females to adult males in contiguous forests.The increased number of males in fragments of Anaimalai Hills may result inincreased food competition between the sexes.
The effect of fragmentation on demography was visible even withinpopulations of lion-tailed macaques in the Anaimalai Hills. The average groupsize was higher in forest fragments than in large forest complexes, and higher in
Group identity and number of individuals ineach group in maximum disturbance habitats
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Group identity and number of individuals in eachgroup in medium disturbance habitats
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Group identity and number of individuals ineach group in relatively undisturbed habitats
GROUP IDENTITYAn2Ip3Va2Ip2An1Va1Ip4Ip1Pa1Ay1AkkKurMa2Hin
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Fig. 3. Identities and size of lion-tailed macaque groups in habitats with maximum, medium, andlittle disturbance.
100 / Singh et al.
private forests (which are all fragmented) than in government-owned forestsinside the Sanctuary, though the difference was not statistically significant.Further, group size in forest fragments showed a high SD, indicating groups ofvery small and very large size. On the other hand, the groups in large forestcomplexes maintained a more or less uniform small size.
The fragmented habitats are under constant human pressure, and the forestcontinues to degrade. The resource base in fragments remains unpredictable onan annual basis, and hence, isolated populations may find it difficult to cope withthe demands of such pressures in the long run. Such isolated populationsresemble island populations which have a higher probability of extinction due tochance disasters [MacArthur & Wilson, 1967]. Already, in the Anaimalai Hills,fragmentation and the increased habitat disturbance has resulted in a significantincrease in group size and density, although the overall age-sex ratio has notshown much variation over the years. Unlike in many other macaque specieswhere commensal groups get access to human food such as crops, garbage, etc.,which may in turn support a larger group size, the lion-tailed macaques have notbeen observed to utilize such resources, except in one degraded fragment atPuthuthotam.
There are several ways in which the macaque groups in fragments can bemanaged. Although not impossible, it is difficult to currently link these fragmentsthrough rainforest corridors. However, a characteristic behavior of lion-tailedmacaques is frequent inter-group adult male migrations [Kumar, 1987; Kumaret al., 2001]. Kumar et al. [2001] suggested that if selected tree species whosefruits are preferred by lion-tailed macaques could be raised along streams or hillslopes between the fragments, it could at least provide paths for males to migratebetween fragments. Coupled with this, attempts could also be made to growselected tree species in the fragments themselves to increase the resource base.This is important because the quality of the habitat in fragments appears to bemore important for animals than the size of the fragment [Kumar et al., 1998].We also suggest that an immediate study on genetics should be undertaken todetermine the extent of homozygosity in groups that have been isolated forseveral decades. Kumar et al. [2001] suggested that if inbreeding is high,swapping adult males among groups should be considered a potential manage-ment technique since lion-tailed macaque females do not exhibit a high degree ofxenophobia towards new adult males.
In the Anaimalai Hills, the forest fragments, especially the privately-ownedfragments in the Valparai plateau, are also important for other wildlife species.They provide population continuity for herpetofauna and small mammals, andalso act as corridors between adjacent regions of the sanctuary for large mammals[Kumar et al., in press]. The lion-tailed macaque is a typical arboreal speciesrequiring uninterrupted canopy contiguity. By using lion-tailed macaque as aflagship species, the management of forest fragments will also benefit otherwildlife in the region.
ACKNOWLEDGMENTS
We acknowledge the help and input from Ajith Kumar, H.S. Sushma, andCornelia Bertsch. Scholarly comments by Irwin Bernstein, Matthew Cooper,Wolfgang Dittus, S.M. Mohnot, and the reviewers of AJP helped to improve thequality of this article. Thanks are due to the Tamil Nadu Forest Department forpermission to carry out research in the Anaimalai Hills, and to the managementof Waterfall Estates for logistic help.
Lion-Tailed Macaque in Anaimalai Hills / 101
REFERENCES
Fooden J. 1982. Ecogeographic segregations ofmacaque species. Primates 23:574–579.
Karanth KU. 1985. Ecological status of thelion-tailed macaque and its rainforest habi-tats in Karnataka, India. IUCN/SSC Pri-mate Specialist Group Newsletter, July. p73–84.
Kumar A. 1987. The ecology and populationdynamics of lion-tailed monkeys (Macacasilenus) in south India. Dissertation, Cam-bridge University, Cambridge.
Kumar A. 1995. The life history, ecology,distribution and conservation problems inthe wild. In: Kumar A, Mollur S, Walker S,editors. The lion-tailed macaque: populationand habitat viability assessment workshop.Coimbatore, India: Zoo Outreach Organiza-tion. p 1–11.
Kumar A, Umapathy G, Prabhakar A. 1995. Astudy on the management and conservationof small mammals in fragmented rainfor-ests in the Western Ghats of south India: Apreliminary report. Primate Conserv 16:53–58.
Kumar A, Sivaganesan N, Umapathy G,Prabhakar A. 1998. A study on the manage-ment of fragmented rainforests of theWestern Ghats for the conservation of faunawith special emphasis on small mammals.Coimbatore, India: Salim Ali Centre forOrnithology and Natural History. 10 p.
Kumar MA, Singh M, Kumara HN, SharmaAK, Bertsch C. 2001. Male migration inlion-tailed macaques. Primate Rep 59:5–17.
Kumar MA, Singh M, Srivastava SK, UdhayanA, Kumara HN, Sharma AK. Distributionpatterns, relative abundance and manage-ment of mammals in Indira Gandhi WildlifeSanctuary, Tamil Nadu, India. J BombayNat Hist Soc (in press).
Lehner PN. 1998. Handbook of ethologicalmethods. 2nd ed. Cambridge: CambridgeUniversity Press. 403 p.
MacArthur RH, Wilson EO. 1967. The theoryof island biogeography. Princeton: Prince-ton University Press. 203 p.
Menon S, Poirier FE. 1996. Lion-tailedmacaque (Macaca silenus) in a dis-turbed forest fragment: activity patternsand time budget. Int J Primatol 17:969–985.
Ramachandran KK, Joseph GK. 2000.Habitat utilization of lion-tailed macaque(Macaca silenus) in Silent ValleyNational Park, Kerala, India. Primate Rep58:17–25.
Singh M, Singh M, Kumar MA, Kumara HN,D’Souza L. 1997a. Distribution and re-search potential of non-human primates inthe Aliyar-Valparai sector of Indira GandhiWildlife sanctuary, Tamil Nadu, India. TropBiodiv 4:197–208.
Singh M, Singh M, Kumara HN, Kumar MA,D’Souza L. 1997b. Inter- and intra-specificassociations of non-human primates inAnaimalai Hills, south India. Mammalia61:17–28.
Singh M, Singh M, Kumar MA, Kumara HN,D’Souza L, Sharma AK. 1998. Behaviorof lion-tailed macaque (Macaca silenus) invulnerable and relatively secure habitatsof Western Ghats, India. Tigerpaper 25:
16–25.Singh M, Kumara HN, Kumar MA,
Sharma AK, DeFalco K. 2000. Status andconservation of lion-tailed macaquesand other arboreal mammals in tropicalrainforests of Sringeri Forest Range, Wes-tern Ghats, Karnataka, India. Primate Rep58:5–16.
Singh M, Kumara HN, Kumar MA,Sharma AK. 2001. Behavioural responsesof lion-tailed macaques (Macaca silenus) toa changing habitat in a tropical rainforestfragment in the Western Ghats, India. FoliaPrimatol 72:278–291.
102 / Singh et al.
