A preliminary study on the activity budget of post released Eastern Hoolock Gibbon Hoolock leuconedys (Mammalia: Primates: Hylobatidae) in Mehao Wildlife Sanctuary, Arunachal Pradesh, India

Main Article Content

Kuladeep Roy
Himani Nautiyal
Soumya Dasgupta


The Wildlife Trust of India has taken a long term responsibility to identify a suitable habitat for the threatened families of Eastern Hoolock Gibbon from a village called Dello in Arunachal Pradesh to a nearby forested area which was the earlier home of this species. There is an ongoing successful rescue and translocation programme since November, 2011 in which four Eastern Hoolock Gibbon families comprising 11 individuals were translocated in three different habitat types in and around the forested area of the Mehao Wildlife Sanctuary.  Post-release monitoring is an obvious and required technique to study the rescued families of Eastern Hoolock Gibbons after translocation to confirm their post-release survival and better livelihood.  The regular monitoring of the activity patterns has helped to understand the habitat utilization and resource use in the newly released sites. Along with the rescue operation, there is an additional task to find out the potential habitats to define as ideal release sites for gibbons.  The post release monitoring was studied through the instantaneous scan sampling method to collect the information mostly about their activity patterns.  The present study describes the overall activity patterns and resource use in the released gibbons on the basis of utilization of different habitat types.  It was observed that the ranging pattern was mostly influenced by the resource availability and forest type.  The gibbon family released in the denser forest habitat developed a general food habit whereas the family from the thinner forest area became the specialist consumer.  However, further detailed study with sufficient data is required to comment on their general ecology. 


Article Details

Author Biographies

Kuladeep Roy, F-13, Sector-8, Noida, Uttar Pradesh 201301, India

Dr. Kuladeep Roy worked as an Assistant Manger and Project lead in Dibang Valley Conservation Project under Wildlife Trust of India. He personally took the responsibility of the Hoolock Gibbon Translocation Project as well as its associated works. He recently joined as a Programme Officer in ENVIS Centre of Zoological Survey of India, Kolkata. 


Himani Nautiyal, School of Natural Science and Engineering, National Institute of Advance studies, IISc Campus, Bengaluru, Karnataka 560012, India

Ms. Himani Nautiyal joined in the Hoolock Gibbon Translocation Project as a volunteer and for her partial fulfilment of the bachelor dissertation work on eastern Hoolock Gibbon in Mehao Wildlife Sanctuary. Presently she works on ecology, behaviour and conservation programme of Central Himalayan Langur in Kedarnath Wildlife Sanctuary as a research associate of National School of Advance Studies.


Soumya Dasgupta, School of Natural Science and Engineering, National Institute of Advance studies, IISc Campus, Bengaluru, Karnataka 560012, India

Mr. Soumya Dasgupta also works as an Assistant Manager in Wildlife Trust of India for last eight years mostly in Arunachal Pradesh and eastern Himalayan region. Presently, he continues his works in central India landscape under the same organization. 



Abes, T. (2001). Flowering phenology, display size, and fruit set in an understory dioecious shrub, Aucuba japonica (Cornaceae). American Journal of Botany 88: 455–461.

Altmann, J. (1974). Observational study of behaviour: Sampling methods. Behaviour 49: 227–267.

Armstrong, D.P., T. Soderquist & R. Southgate (1994). Designing experimental reintroductionsas experiments, pp. 27–29. In:

Serena, M. (ed.). Reintroduction Biology of Australian and NewZealand Fauna. Surrey Beatty & Sons, Chipping Norton, New South Wales

Boesch, C. (1994). Cooperative hunting in wild chimpanzees. Animal Behavior 48: 653–667

Bollen, A. & G. Donatl (2005). Phenology of the littoral forest of Sainte Luce, Southeastern Madagascar. Biotropica 37: 32–43.

Cluttion-Brock, T. & P. Harvey (1977). Primate ecology and social organization. Journal of Zoology 183: 1–3.

Chetry, D., R. Chetry, A. Das, C. Loma & J. Panwor (2008). New distribution records for Hoolock leuconedys in India. Primate Conservation 23: 125–128.

Cheyne, S.M. (2004). Assessing rehabilitation and reintroduction of captive-raised gibbons in Indonesia. (Doctoral dissertation). University of Cambridge, Cambridge, England

Di Fiore, A. (2004). Diet and feeding ecology of Woolly Monkeys in a western Amazonian rain forest. International Journal of Primatology 25: 767–801.

Fox, E., C. van Schaik, A. Sitompul & D. Wright (2004). Intra-and interpopulational difference in Orangutan (Pongo pygmaeus) activity and diet: implications for the invention of tool use. American Journal or Physical Anthropology 125: 162–174.

Foster, S.A. & C.H. Janson (1985). The relationship between seed size and establishment conditions in tropical woody plant. Ecology 66: 773–780.

Go, M. (2010). Seasonal changes in food resource distribution and feeding sites selected by Japanese macaques on Koshima Islet, Japan. Primates 51: 149–158.

Goodall, J. (1986). The Chimpanzees of Gombe: Patterns of Behavior, Harvard University Press, Cambridge, MA.

Houle, A., C.A. Chapman & W.L. Vickery (2004). Tree climbing strategies for primate ecological studies. International Journal of Primatology 25: 237–260.

IUCN (1998). IUCN Guidelines for Reintroductions. IUCN/SSC Re-introduction Specialist Group, Gland and Cambridge.

Kapos, V., A. Bzlmford, R. Aveling, P. Bubb, P. Carey, A. Entwistle, J. Hopkins, J. Mulliken, R. Safford, A. Stattersfield, M. Walpole & A. Monica (2009). Outcomes, not implementation predict conservation success. Oryx 43(3): 336–342.

Kleiman, D. & A. Rylands (2002). Lion Tamarins: Biology and Conservation. Smithsonian Institution Press, Washington, DC, 422pp.

Knott, C.D. (1998). Changes in orangutan caloric intake, energy balance and ketones in response to fluctuating fruit availability. International Journal of Primatology 19: 1061–1079.

Knott, C.D. (2005). Energetic Responses to Food Availability in The Great Apes: Implications for Hominoid Evolution, pp. 351–378. In: Brockman, D.K. & C.P. van Schaik (ed.). Seasonality in Primates: Studies of Living and Extinct Human and Non-human Primates. Cambridge University Press, Cambridge.

Lahann, P. (2008). Habitat utilization of three sympatric cheirogaleid lemur species in a littoral rain forest of southeastern Madagascar. International Journal of Primatology 29: 117–134.

Lehner, P.N. (1996). Handbook of Ethological Methods. Cambridge University Press, Great Britain.

Leighton, M. & D.R. Leighton (1982). The relationship of size of feeding aggregate to size of food patch: Howler Monkeys (Alouatta palliata) feeding in Trichilia cipo fruit trees on Barro Colorado Island. Biotropica 14: 81–90.

Loiselle, B.A. & J.G. Blake (1990). Diets of understory fruit eating birds in Costa Rica: Seasonality and resource abundance. Studies in Avian Biology 13: 91–103.

Masi, S., C. Cipolletta & M.M. Robbins (2009). Western Lowland Gorillas (Gorilla gorilla gorilla) change their activity patterns in response to frugivory. American Journal of Primatology 71: 91–100; http://dx.doi.org/10.1002/ajp.20629

Miller, K.E. & J.M. Dietz (2004). Fruit yield, not DBH or fruit crown volume, correlates with time spent feeding on fruits by wild Leontopithecus rosalia. International Journal of Primatology 25: 27–39.

Mootnick, A.R. & R.D. Nadler (1997). Sexual behavior of maternally separated gibbons (Hylobates spp.). Developmental Psychobiology 2: 149–161.

Naro, E., E.L. Mero, E. Naro, K. Kapfo, K. Wezah, K. Thopi, K. Rhakho, L. Akami, L. Thopi, M. Chirhah, T. Chirhah, T. Tsuhah, T. Thopi, W Wezah, W.L. Mero, W. Thopi, K. Thopi, T. Naro, W. Tsuhah, N. Dahanukar & P.B. Molur (2015). Project hunt: an assessment of wildlife hunting practices by local community in Chizami, Nagaland, India. Journal of Threatened Taxa 7(11): 7729–7743; http://dx.doi.org/10.11609/JoTT.o4219.7729-43

Reddy, C.S., S. Babar, A. Giriraj, K.N. Reddy & K.T. Rao (2008). Structure and floristic composition oftree diversity in tropical dry deciduous forest of Eastern Ghats, southern Andhra Pradesh, India. Asian Journal of Scientific Research 1: 57–64.

Remis, M.J. (1994). Feeding Ecology and Positional Behavior of Western Lowland Gorillas (Gorilla gorilla gorilla) in the Central African Republic. PhD Thesis, Yale University, New Haven.

Sayers, K. & M.A. Norconk (2008). Himalayan Semnopithecus entellus at Langtang National Park, Nepal: diet, activity patterns, and resources. International Journal of Primatology 29: 509–530.

Seddon, P.J. (1999). Persistence without intervention: assessing success in wildlife reintroductions. Trends in Ecology & Evolution 14: 503.

Seddon, P.J., D.P. Armstrong & R.F. Maloney (2007). Developing the science of reintroduction biology. Conservation Biology 21(2): 303–312; http://dx.doi.org/10.1111/j.1523-1739.2006.00627.x

Singh, M., H.N. Kumara, M.A. Kumar & A.K. Sharma (2001). Behavioural responses of Lion-tailed Macaques (Macaca silenus) to a changing habitat in atropical rain forest fragment in the Western Ghats, India. Folia Primatologica 72: 278–291.

Srivastava, A. (2006). Conservation of threatend primates of northeast india. Primate Conservation 20: 107–113.

Strum, S.C. (2005). Measuring success in primate translocation: A baboon case study. American Journal of Primatology 65: 117–140; http://dx.doi.org/10.1002/ajp.20103

Takahashi, H. (2002). Female reproductive parameters and fruit availability: factors determining onset of estrus in Japanese macaques. American Journal of Primatology 57: 141–153.

Tickell, S.R. (1864). Notes on the gibbon of Tenasserim, Hylo­bates lar. Journal of the Asiatic Society of Bengal 33: 196–199.

Tilson, R., U.S., Seal, K. Soemarna, W. Ramono, E. Sumardja, S. Poniran, S.C. van Schaik, M. Leighton, H. Rijksen & A. Eudey (1993). Orangutan population and habitat viability analysis report. Orangutan population and habitat viability analysis workshop, Medan, North Sumatra, Indonesia

Watts, D.P. (1988). Environmental influences on Mountain Gorilla time budgets. American Journal of Primatology 15: 295–312.

Watts, D.P. (1996). Comparative socio-ecology of Gorillas, pp. 16–28. In: McGrew, W., L. Marchant & T. Nishida (ed.). Great Apesocieties. Cambridge University Press, Cambridge.

Watts, D.P. (1998). Long-term habitat use by Mountain Gorillas (Gorilla gorilla beringei). Consistency, variation, and home range size and stability. International Journal of Primatology 19: 651–680.

Wich, S.A., G. Fredriksson & E.H.M. Sterck (2002). Measuring fruit patch size for three sympatric Indinesian primate species. Primates 43: 19–27.

Zimmerman, J.K., S.J. Wright, O. Calderon, M.A. Pagan & S. Paton (2007). Flowering and fruiting phenologies of seasonal neotropical forests: the role of annual changes in irradiance. Journal of Tropical Ecology 23: 231–251.