Abstract
Reintroduction of Sumatran orangutans can be an important tool to conserve the species in the face of the current decline of wild populations. Monitoring ex-captive orangutans during the reintroduction process provides insight into their adaptation to forest life and is important for evaluating the success of such programs. We investigated activity patterns, food choice, height use, and nest-building abilities of 8 immature orangutans at a reintroduction station in Sumatra. All focal individuals spent most of their time in the forest feeding, but at a lower proportion than wild conspecifics. Among the focal individuals, the behavior of orangutans that avoided human contact differed in several aspects from those that were human bonded. Their diet was composed mainly of fruits, similar to the food choice of wild orangutans, and their ground-avoidance and superior nest-building abilities indicated more effective predation-avoidance behavior vs. that of human-bonded animals. Finally, these immatures showed regular social contact with more experienced conspecifics, which ultimately may facilitate the social learning of local feral expertise. Human-bonded individuals, in contrast, preferentially stayed on the ground and at low heights and rarely built nests, thereby increasing predation risk. Their choice of leaves over fruits as foods indicated a less effective foraging strategy. Nevertheless, this group exhibited individual learning trends toward an adult-like foraging pattern and height use. We conclude that social interactions with conspecifics and humans, especially during an early developmental period, can affect adaptation to forest life and probably also influence the success of orangutan reintroduction processes.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Baker, L. R. (2002). Guidelines for nonhuman primate re-introductions. Newsletter of the Re-introduction Specialist Group of the IUCN´s Species Survival Commission (SSC), 21.
Beck, B., Walkup, K., Rodrigues, M., Unwin, S., Travis, D., & Stoinski, T. (2007). Best practice guidelines for the re-introduction of Great Apes. Gland: SSC Primate Specialist Group of the World Conservation Union.
Byrne, R. (1997). The technical intelligence hypothesis: And additionally evolutionary stimulus to intelligence? In A. Whiten & R. Byrne (Eds.), Machiavellian intelligence II: Extensions and evaluations (pp. 289–311). Cambridge: Cambridge University Press.
Delgado, R. A., Jr., & van Schaik, C. P. (2000). The behavioural ecology and conservation of the orangutan (Pongo pygmaeus): a tale of two islands. Evolutionary Anthropology, 9, 201–218.
Fox, E. A., van Schaik, C. P., Sitompul, A., & Wright, D. N. (2004). Intra-and interpopulational differences in orangutan (Pongo pygmaeus) activity and diet: implications of the invention of tool use. American Journal of Physical Anthropology, 125, 162–174.
Galdikas, B. M. F. (1988). Orangutan diet, range, and activity at Tanjung Putting, Central Borneo. International Journal of Primatology, 9, 1–35.
Goller, K. (2004). Verhaltensbeobachtungen an ausgewilderten Sumatra Orang-Utans. MSc thesis, University of Munich, München.
Hauser, M. D. (1992). The transition to foraging independence in free-ranging vervet monkeys. In B. G. Galef Jr., M. Mainardi, & P. Valsecchi (Eds.), Behavioural aspects of feeding, basic and applied research in mammals, 6th Workshop of the International School of Ethology, Erice, Sicily, Italy (pp. 165–202). Chur: Harwood Academic.
Jaeggi, A. V., van Noordwijk, M. A., & van Schaik, C. P. (2008). Begging for information: Mother-offspring food sharing among wild Bornean orangutans. American Journal of Primatology, 70, 533–541.
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.
Leighton, M. (1993). Modeling dietary selectivity by Bornean orangutans: evidence for integration of multiple criteria in fruit selection. International Journal of Primatology, 14, 257–313.
MacKinnon, J. (1974). The behaviour and ecology of wild orang-utans (Pongo pygmaeus). Animal Behaviour, 22, 3–74.
Martin, P., & Bateson, P. (2000). Measuring behaviour: An introductory guide. Cambridge: Cambridge University Press.
Meyer, D. (2005). Adaptation an den natürlichen Lebensraum: Verhaltensbeobachtungen an zu rehabilitierenden Sumatra Orang Utans (Pongo abelii) im Bukit Tigapuluh Nationalpark Sumatra. MSc thesis, University of Berlin, Berlin.
Morrogh-Bernard, H., Husson, S., & McLardy, C., (2002). Orang-Utan data collection standardisation. In Orang-Utan Cultural Workshop, San Anselmo, CA. http://www.aim.unizh.ch/orangutannetwork/FieldGuidelines (Accessed September 26, 2006).
Morrogh-Bernard, H. C., Husson, S. J., Knott, C. D., Wich, S. A., van Schaik, C. P., & van Noordwijk, M. A. (2009). Orangutan activity budgets and diet. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 119–133). New York: Oxford University Press.
Pratje, P. H. (2000). Fruit tree availability in Bukit Tigapuluh National Park as an estimator of Orang-Utan carrying capacity. In Orang-Utan Project—Bukit Tigapuluh Survey of the Frankfurt Zoological Society. Unpublished Report. Frankfurt Zoological Society, Frankfurt.
Pratje, P. H. (2006a). The Sumatran Orangutan Conservation Programmes Release Program in Bukit Tigapuluh National Park, Jambi, Sumatra. Paper presented at the ARAZPA conference 2006, Wellington, NZ.
Pratje, P. H. (2006b). Worksheets for Sumatran orang-utan (Pongo abelii) reintroduction. Frankfurt Zoological Society/Sumatran Orang-utan Conservation Program 2006. Unpublished report. Frankfurt Zoological Society, Frankfurt.
Pratje, P. H. (2009). Sumatran orangutan conservation project progress report 2002–2009. Unpublished report. Frankfurt Zoological Society, Frankfurt.
Pratseyo, D., Ancrenaz, M., Morrogh-Bernard, H. C., Utami Atamok, S. S., Wich, S. A., & van Schaik, C. P. (2009). Nest building in orangutans. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 269–277). New York: Oxford University Press.
Rijksen, H. D. (1978). A field study on Sumatran Orang-utans (Pongo pygmaeus abelii Lesson, 1827): Ecology, behaviour and conservation. Wageningen: H. Veenman & Zonen.
Rijksen, H. D., & Meijaard, E. (1999). Our vanishing relative: The status of wild orang-utans at the close of the twentieth century. Dordrecht: Kluwer Academic.
Robertson, J. M. Y., & van Schaik, C. P. (2001). Causal factors underlying the dramatic decline of Sumatran orang-utan. Oryx, 35, 26–38.
Rodman, P. S. (2000). Great ape models for the evolution of human diet. http://www.cast.uark.edu/local/icaes/conferences/wburg/posters/psrodman (Accessed January 18, 2004).
Russon, A. E. (1998). The nature and evolution of intelligence in orangutans (Pongo pygmaeus). Primates, 39, 485–503.
Russon, A. E. (2002). Return of the native: cognition and site-specific expertise in orangutan rehabilitation. International Journal of Primatology, 23, 461–478.
Russon, A. E. (2003). Innovation and creativity in forest-living rehabilitant orang-utans. In S. M. Reader & K. N. Laland (Eds.), Animal innovation (pp. 279–304). Oxford: Oxford University Press.
Russon, A. E. (2006). Acquisition of complex foraging skills in juvenile and adolescent orangutans (Pongo pygmaeus): developmental influences. Aquatic Mammals, 32, 500–510.
Russon, A. E. (2009). Orangutan rehabilitation and reintroduction. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 327–350). New York: Oxford University Press.
Russon, A. E., & Galdikas, B. M. F. (1995). Constrains on Great Apes’ imitation: model and action selectivity in rehabilitant orangutan (Pongo pygmaeus) imitation. Journal of Comparative Psychology, 109, 5–17.
Russon, A. E., Handayani, D. P., Kuncoro, P., & Ferisa, A. (2007). Orangutan leaf-carrying for nest-building: toward unravelling cultural processes. Animal Cognition, 10, 189–202.
Russon, A. E., Wich, S. A., Ancreaz, M., Kanamori, T., Knott, C. D., Kuze, N., et al. (2009). Geographic variation in orangutan diets. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 135–155). New York: Oxford University Press.
Singleton, I. (2004). Sumatran Orangutan Conservation Programme. SOCP News, 9.
Singleton, I., & van Schaik, C. P. (2002). The social organisation of a population of Sumatran orang-Utans. Folia Primatologica, 73, 1–20.
Sugardjito, J., te Boekhorst, I. J. A., & van Hoof, J. A. R. A. M. (1987). Ecological constraints on the grouping of wild orang-utans (Pongo pygmaeus) in the Gunung Leuser National Park, Sumatra, Indonesia. International Journal of Primatology, 8, 17–41.
te Boekhorst, I., Schurmann, C., & Sugardjito, J. (1990). Residental status and seasonal movements of wild orangutans in Gunung Leuser Reserve (Sumatera, Indonesia). Animal Behaviour, 39, 1089–1109.
Thorpe, S. K. S., & Crompton, R. H. (2009). Orangutan positional behaviour. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 33–47). New York: Oxford University Press.
Utami, S. S., Wich, S. A., Sterck, E. H. M., & van Hoof, J. A. R. A. M. (1997). Food competition between wild orangutans in large fig trees. International Journal of Primatology, 18, 909–927.
van Adrichem, G. G. J., Utami, S. S., Wich, S. A., van Hoof, J. A. R. A. M., & Sterck, E. H. M. (2006). The development of wild immature Sumatran orangutans (Pongo abelii) at Ketambe. Primates, 47, 300–309.
van Noordwijk, M. A., & van Schaik, C. P. (2005). Development of ecological competence in Sumatran orangutans. American Journal of Physical Anthropology, 127, 79–94.
van Noordwijk, M. A., Sauren, S. E. B., Nuzuar, Abulani, A., Morrogh-Bernard, H. C., Utami Atmoko, S. S., et al. (2009). Development of independence. In S. A. Wich, S. S. Utami Atmoko, T. Mitra Setia, & C. P. van Schaik (Eds.), Orangutans—Geographic variation in behavioral ecology and conservation (pp. 189–203). New York: Oxford University Press.
van Schaik, C. P. (1999). The socioecology of fission-fusion sociality in orangutans. Primates, 40, 69–86.
van Schaik, C. P. (2000). Securing a future for wild orang-utan. The apes: Challenges for the 21st century. Chicago: Brookfield Zoo.
van Schaik, C. P. (2004). Among orangutans: Red apes and the rise of human culture. Cambridge and London: Belknap Press of Harvard University Press.
van Schaik, C. P., Deaner, R. O., & Merrill, M. Y. (1999). The conditions for tool-use in primates: implications for the evolution of material culture. Journal of Human Evolution, 36, 719–741.
van Schaik, C. P., Monk, K. A., & Robertson, J. M. Y. (2001). Dramatic decline in orang-utan numbers in the Leuser Ecosystem, Northern Sumatra. Oryx, 35, 14–25.
van Schaik, C. P., Ancrenaz, M., Borgen, G., Galdikas, B. M. F., Knott, C. D., Singleton, I., et al. (2003). Orangutans cultures and the evolution of material culture. Science, 299, 102–105.
van Schaik, C. P., Husson, S., Meijaard, E., Singleton, I., & Wich, S. A. (2004). The status of the orangutan in Indonesia 2003. Orangutan population and habitat viability assessment: Final report to the Orangutan Foundation, Jakarta, Indonesia.
Wich, S. A., Singleton, I., Utami-Atmoko, S. S., Geurts, M. L., Rijksen, H. D., & van Schaik, C. P. (2003). The status of the Sumatran orang-utan Pongo abelii: an update. Oryx, 37, 49–54.
Wich, S. A., Utami-Atmoko, S. S., Mitra Setia, T., Rijksen, H. D., Schürmann, C., van Hooff, J. A. R. A. M., et al. (2004). Life history of wild Sumatran orangutans (Pongo abelii). Journal of Human Evolution, 47, 385–398.
Wich, S. A., Utami-Atmoko, S. S., Mitra Setia, T., Djoyosudharmo, S., & Geurts, M. L. (2006). Dietary and energetic responses of Pongo abelii to fruit availability fluctuations. International Journal of Primatology, 27, 1535–1550.
Yeager, C. P. (1997). Orangutans rehabilitation in Tanjung Puting National Park, Indonesia. Conservation Biology, 11, 802–805.
Acknowledgments
We thank the Indonesian Institute of Science (LIPI) for permission to work in Indonesia, and the Directorate General of Forest Protection and Nature Conservation and the Nature Conservation Departments of the Provinces of Riau and Jambi for permission to conduct research at Bukit Tigapuluh National Park. We thank the University of Vienna for providing financial support for this study and the Frankfurt Zoological Society for logistic as well as financial support. We thank Isa, Damson, Suparman, Arlen, Habib, Josua, Krismanko, Marjuni, Sumarno, Puji, Syarif, and all local guides for their help in the field, and Betty for administrational advice. Finally, we thank 2 anonymous reviewers for many helpful comments on an earlier version of this manuscript.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Riedler, B., Millesi, E. & Pratje, P.H. Adaptation to Forest Life During the Reintroduction Process of Immature Pongo abelii . Int J Primatol 31, 647–663 (2010). https://doi.org/10.1007/s10764-010-9418-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10764-010-9418-2