Jurnal Biologi Indonesia 7(2):213-220 (2011)

Javan Leaf Monkey (Trachypithecus auratus) Movement in a Frag- mented Habitat, at Bromo Tengger Semeru National Park, East Java, Indonesia

M.Hari Subarkah ¹, Novianto Bambang Wawandono ², Satyawan Pudyatmoko ³, Subeno ³, Sandy Nurvianto ³, & Arif Budiman ¹

¹ Wildlife researcher at Wildlife Laboratory Faculty of Forestry Gadjah Mada University, ² Biodiversity Conservation, Departement of Forestry ³Faculty of Forestry Gadjah Mada University. E-mail: [email protected]

ABSTRAK

Pergerakan Lutung budeng (Trachypithecus auratus) didaerah habitat terfragmentasi Taman Nasional Bromo Tengger Semeru, Jawa Timur, Indonesia. Pergerakan lutung budeng di daerah habitat terfragmentasi diamati dengan metode transek. Hasil kajian menunjukkan bahwa ada empat kelompok masing masing beranggotakan 12 (grup A), 16 (grup B), 15 (grup C) dan 12 lutung (grup D). Penelitian yang dilakukan disekitar hunian penduduk, jalan, hutan terdegradasi dan jalan-jalan setapak mengindikasikan bahwa lutung dalam aktivitas hariannya memerlukan waktu 32,82% diantaranya digunakan untuk makan, 30,97% untuk istirahat dan sisanya 31,79 untuk pergerakan perpindahan. Lutung dalam aktivitasnya 50,53% menggunakan wilayah puncak kanopi tumbuhan, 41,99%menggunakan kanopi tumbuhan bagian tengah dan hanya 2,49 % yang menggunakan kanopi bawah.

Kata kunci: Lutung budeng (Trachypithecus auratus), habitat terfragmentasi

INTRODUCTION adapt to changes in order to survive; fail- ure to adapt dooms species to extinction Most primate species live in tropical (Isabirye-Basuta & Jeremiah 2008; forests, (Mittermeier & Cheney 1987; Sharkley1996, Newsome et al. 2005). Chapman et al. 2006) where 2 major Habitat loss and fragmentation are threats are habitat destruction and hunt- associated with fewer resources, greater ing by human (Mittermeier & Cheney isolation, and more intense and far-reach- 1987). Alteration of forests into agricul- ing edge effects (Laurance & Bierregaard tural land, degraded function of the con- 1997), and both are considered was ma- servation area, are several causes de- jor threats to wildlife. Unless the current creasing the primate population. Primate rate of forest conversion is halted, it is populations, like those other organisms, inevitable that more and more primate face the challenges of coping with the populations will live in an isolated frag- dynamic of their habitat, because habitat ment (Isabirye-Basuta & Jeremiah 2008). are continually changing and primate must Understanding the biology behind the dis

213 Subarkah et al. tinction between species at risk and more vegetation data collected using Point persistent species should help inform con- Centered Quarter-Method (Mueller- servation efforts (Gibbons & Harcourt Dumbois & Ellenberg 1974) only to the 2009). level of the tree with a minimum diam- Coban Trisula are an intensive used eter of 35cm, measured at breast height, areas in Bromo Tengger Semeru National and 3) observations of daily activity of Park, consist of 3 natural waterfalls, and Javan langurs using Focal Animal Sam- also the habitat for the vurnerable of javan pling method (Lehner 1976) by observ- leaf monkey (IUCN 2010). In addition to ing the feeding, social, resting and mov- tourism, this region is also intensively used ing. by local people to take the wood, fodder, mushrooms, honey, medicine and kinds RESULTS of forest fruits for consumption. The lo- cation immediatelies adjacent to the cul- Coban Trisula and surounding are tivation, split by a highway connecting intensif used areas, as ecotourism object. Bromo and district of Malang and located The object were consisting three natural between Gubugklakah and Ngadas vil- waterfalls, namely upper coban, middle lages. This condition has turned the area coban and down coban, flows in Lajing fragmented. This study aims to determine river. The management has created semi the daily movements in the area of Coban permanent trail to reach the object, about Trisula as forms of javan leaf monkey ad- 600 meters long. The object was opened aptation in fragmented habitat. only in weekend, and visited by tourist about 50 - 100 peoples a day. MATERIALS AND METHODS Coban Trisula located as the border of Bromo Tengger Semeru National The study sites was at Coban Trisula Park, directly connected with resort conservation area, Bromo Tengger localvillagers cultivation. The area is also Semeru National Park, at coordinate 08o cut by permanent road connecting Bromo 00'11.5"- 07o 59'52.3"LS and 112o mountain and district Malang and 3 vil- 51'51.6"-112o 52'21.4"BT, at 1335-1591 lages that are Ranu Pani village, Ngadas m asl, covering 89 hectares. Administra- village and Gubugklakah village. Inside tively it is located in the Gubugklakah vil- the area there are many trail used by lo- lage Malang, East Java. This research cal villagers taking any resources needed. was conducted in August-December These facilities make villagers and visi- 2009 and January 2010. tors can access freely. Inside the loca- The methods used during the study tion, there are three natural rivers that is were: 1) Population survey of Javan lan- Sadam river, Lajing river and Amprong gurs using Line Transect Method river. (Strukhsaker 1981) conducted onece Illegal cutting for cabin, firewood each month, and then calculated the av- and cattle food for cows and goat are erage number of individuals found; 2) the biggest contribution to the habitat loss

214 Javan Leaf Monkey (Trachypithecus auratus) Movement

Figure 1. Habitat type of javan leaf monkey (Trachypithecus auratus) at Coban Trisula.

Figure 2. Ilegal cutting for cabin and cattle food. and habitat fragmentation inside and out- viduals that are divided into four groups. side the area. It was done by local vil- Group 1 was up to 12 individuals, group lagers from Gubugklakah village, Tosari 2 was 12 individuals, group 3 was 15 in- village and Duwet village. Illegal cutting dividuals and group 4 was16 individuals. is intensive in the dry season, and de- Sex ratio is 1:1.5 (19 males and 29 fe- creasing in rainy season. It was created males). The age structure and sex ratio a "hole" in the area and formed a liaison of each group are presented in the Table at each habitat corridor that is used for 1. moving by Javan leaf monkey to explore The table shows, density of javan the home range. leaf monkey at Coban Trisula is 0,6 The population survey was con- individu per hectare. The density was ducted a month over study period. It higher than in Blok Ireng-Ireng which showed a population density of 55 indi- consisted of 64 individuals at area 428

215 Subarkah et al.

hectars, means 0,1 individu per hectare. ranga sp), Dadap (Erythrina orien- The observation samples consist of group talis), Nyampuh Sentul (Actinodaphne 1 and group 2, while group 3 and group 4 sp) and Salam (Syzygium polyanthum). are considered equal. Observations were done on daily behavior, exploiting strata DISCUSSION canopies, canopy height and density of trees used in its daily activities. Canopy level used by javan leaf To determine the density of trees monkey were different from any activi- used for moving, feeding and other ac- ties. During the observations, canopy tivities, vegetation analysis was con- level used by javan leaf monkey is pre- ducted using the Centre Point-Quadrat sented in the Figure3 Method. The density of trees is 228.7 The charts shows (Table 2), canopy individuals per hectare, the average dis- used at top level are 50,53%, at middle tance between trees is 7.34 meters, the level are 41,99% and lower canopy used average tree height is 8.40 meters, av- 4,98%. It seems associated with the habit erage canopy width is 7.13 meters and of javan leaf monkey as arboreal primate. canopy density is 41.51% (scale 3 of Utilization of canopy level was associ- Braun-Blanquet Scale). Species found ated with the height and canopy density, include Danglo (Engelhardtia spicata), and diversity of tree species such as feed- Tritih (Nitrocous sp), Preh (Ficus spp), ing trees, shelter and so forth. For ex- Anggrung (Trema orientalis), Bodak ample, Preh (Ficus spp), was used as a (Nauclea orientalis), Blarang (Maca- feeding trees, resting and social activi-

Table 1. Population, age structure and sex ratio of javan leaf monkey at Coban Trisula and surrounding Population, age structure and sex ratio No Groups Adult Sub-adult Juvenile Total Male Female Male Female 1 Group 1 3 6 2 - 1 12 2 Group 3 2 4 1 1 4 12 3 Group 2 3 6 3 2 1 15 4 Group 4 3 6 2 4 1 16 Total 11 22 8 7 7 55

Table 2. Height and canopy density (in average) of trees at core area in home range.

Resting Feeding Social Sleeping Item/ Canopy Canopy Canopy Canopy Heigh Height Heigh Heigh Activities Density Density Density Density t (m) (m) t (m) t (m) (%) (%) (%) (%) Group 1 23.86 47.95% 24.77 53.33% 26.47 57.35% 27.67 58.33% Group 2 24.08 47.88% 20.87 45.00% 25.00 52.78% 25.57 52.86% Overlapping 25.11 53.42% 23.55 54.50% 28.92 55.00% 29.20 59.50%

216 Javan Leaf Monkey (Trachypithecus auratus) Movement ties, also as moving trees to other areas. eral species of plants and shrubs around Equitable form of branching, 45% canopy the river, some areas where there are no density, 20 meters height and shape of human activities. the rounded canopy javan leaf monkey Daily activities of javan leaf monkey, used top, middle and lower canopy level. showed on Figure 4 But, Anggrung (Trema orientalis), av- Average percentage of daily activity erage height 20 meters and a canopy of javan leaf monkey for rest and social density 25%, more often utilized as a activities amounted to 30.97%. Both resting trees and social activities at the activities were performed in the same middle canopy. While types of Bodak span of time before afternoon (07.30 - (Nauclea orientalis), with the same 10.00 am) and in the afternoon (12.00 - height and canopy density 40%, more 14.30 pm). Social activities that were often utilized as resting trees social ac- found during the observation is grooming tivities on top, middle and lower canopy and playing, but no breeding activity had level. During observations, sometimes been found. Foraging and eating javan leaf monkey found above the approximately 31.82% & were ground to find insects, consuming sev- performed by all individuals' javan leaf

50.53%

41.99%

4.98% 2.49%

Top Canopy Middle Canopy Lower Canopy Above the Ground Canopy Level

Figure 3. Percentage of time budget in javan leaf monkey daily activity

Resting and Moving & Social Activity, Ranging, 31.79% 30.97%

Foraging & Eating, 31.82%

Figure 4. Canopy level used by javan leaf monkey

217 Subarkah et al. monkey in the morning (06.00 - 07.30 am) move easily to another tree and hide. The and afternoon periods (14.30 - 17.00 pm). average number of canopy density are While moving activity and ranging is 47.95% used by group 1, 47.88% used approximately 31.79%, which is by the Group 2 and 53.42% in overlapping performed in the morning, afternoon and home range, because Javan langurs are evening at the home range in each group. adequately shielded from sunlight, rain, Based on the observation and wind, low temperature and relatively calculation above, it is known that the hidden from predators. javan leaf monkey have good adaptability At feeding activity, the average to the state of the fragmented habitat. height of trees that was used by group 1 Utilization of trees were various in daily is 24.77 m, 20.87 m in group 2 and 23.55 activities formed important areas and m in overlapping home range. The frequently visited, known as core area. average number of canopy density was Core areas used by javan leaf monkey 53.33% in Group 1, 45.00% in group 2 are closely linked with the height and and 54.50% in overlapping home range. density of tree canopies. Height of trees Canopy height and density associated was used by Javan langurs to avoid with the volume of feed that is available, harassment and threats from both human although sometimes javan leaf monkey and predator. While the canopy density also moved above the ground to eat selected by javan leaf monkey was insects, several types of shrubs and plants mainly to protect themselves from such as kecubung (Brugmansia sp), sunlight, rain, wind and low temperatures. kaliandra (Calliandra calothyrsus), Utilization of core areas in resting, mencokan (Debregeasia sp). feeding, social activities and sleeping was Social activities carried out during different one to another, and are resting time such as grooming, playing presented in the Table 2 below. In the and mating. At the core areas, social observation of home range, there is activities are carried out on trees with overlapping between home range group an average height of 26.47 m in group 1, 1 and group 2. At each home range of 25.00 m in group 2 and in overlapping two groups, there are a core area used home range 28.92 m. Canopy density in jointly by the Group 1 and Group 2. Group 1 amounted to 57.35%, in Group Resting activities were spread on 2 was 52.78% and in overlapping home several trees on the top and middle range of 55.00%. While playing, javan canopy level, on average height of 23.86 leaf monkey used top and middle canopy meters in home range of Group 1, 24.08 level to practice running, jumping, meters in home range of Group 2 and wrestling and climbing. This activity was 25.11 meters in overlapping home range. carried out by sub-adult and juvenile, Higher trees were used by javan leaf occasionally watched by their mother. monkey in circumstances of potential Sometimes another adult female or males nuisance and threat. When interference occasionally join into. Grooming and or threat appears, javan leaf monkey can other social activities are often carried

218 Javan Leaf Monkey (Trachypithecus auratus) Movement out by two or more individuals, alternately, sunlight, wind, rain, low temperature as conducted on middle canopy level or a well as a place to hide from threats and branching tree or large tree trunks and predators and human disturbance. flat. Another social activity is breeding. In Coban Trisula Resort, conflict of However, during observations the social interest between human and javan leaf activity was not found. monkey could become a serious threat Javan leaf monkey stopped their to the existence or the preservation of activities by entering the aleeping trees these animals, which are death and/or at 17:30 to 18:00. Selection of trees to displacement to another areas or habitats sleep are very important because javan that are more supportive. Therefore, leaf monkey must ensure that the tree conservation action to conserve javan has well-height and high density leaf monkey has to be taken in the future. canopies. The average numbers of tree height are 27.67 m in group 1, 25.57 m in ACKNOWLEDGEMENTS group 2 and 29.10 m in overlapping home. Canopy density in sleeping tree Many thanks to Mr. Novianto of group 1 was 58.33%, group 2 was Bambang Wawandono, Director of 52.86% and in overlapping home range Biodiversity Conservation, Departement were 59.50%. Sleeping trees used were of Forenstry, The Nature Conservancy higher and more densely than the height (TNC), Directorate General of Higher and canopy density trees for other Education (DIKTI), Bogor Agricultural activities. Tree height based on a better University (IPB), The Indonesian sense of security from the threat of Biological Society (PBI), Association for predators, whereas high canopy density Tropical Biology and Conservation for shelter from the wind and cold air, (ATBC), Bromo Tengger Semeru and from the rain. National Park and all staff, and many many people are not name here. CONCLUSIONS REFERENCES These observations concluded that javan leaf monkey was able to adapt to Chapman, CA., MJ. Chapman & HAC. the fragmented habitat areas. Height and Eeley. 2006. What hope for canopy density of trees have important African Primate Diversity?. functions in supporting the daily activities African J. Ecol. 44: 116-133 of Javan langurs such as feeding Dumbois, DM. & H. Ellenberg. 1974. behavior, resting, social activities and Aims and Method of Vegetation moving. Tree height associated with a Ecology. John Wiley & Sons. New sense of preferential because they feel York, London, Sydney, Toronto safe from harassment and threat of Gibbons, MA. & AH. Harcourt. 2009. predators. While the density of the Biological correlates of extinction canopy allows protecting the body from and persistence of primates in small

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Received: July 2010 Accepted: Aprl 2011

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