References

1. Taylor A.B. 2006. Feeding behavior, diet, and the functional consequences of jaw form in orangutans, with implications for the evolution of Pongo. Journal of Human Evolution 50:377-393. [PDF]

2. Leighton, M. 1993. Modeling dietary selectivity by Bornean orangutans: Evidence for integration of multiple criteria in fruit selection. International Jouranl of Primatology 14(2):257-313. [PDF]

3. Lockwood C.A., W.H. Kimbel, and J.M. Lynch. 2004. Morphometrics and hominoid phylogeny: support for a chimpanzee-human clade and differentiation among great ape subspecies. PNAS 101(13):4356-4360. [PDF]

4. van Schaik, C.P., M. Ancrenaz et. al. 2003. Orangutan cultures and the evolution of material culture. Science 299:102-105. [PDF]

5. Knott, C.D. 1998. Changes in orangutan caloric intake, energy balance, and ketones in response to fluctuating fruit availability. International Journal of Primatology 19(6):1061-1079. [PDF]

6. Koop B.F., D.A. Tangle et. al. 1989. A molecular view of primate phylogeny and important systematic and evolutionary questions. Molecular Biological Evolution 6(6):580-612. [PDF]

7. Galdikas, B.M.F. 1989. Orangutan tool use. Science 243(4888):152. [PDF]

8. http://www.fas.harvard.edu/~gporang/ [Link]

9. van Schaik, C.P., Ancrenaz, M., Borgen, G., Galdikas, B., Knott, C.D., Singleton, I., Suzuki, A., Utami, S.S., & Merrill, M.Y. 2003. Orangutan cultures and the evolution of material culture. Science 299: 102-105

10. MacKinnon, J. 1971. The orangutan in Sabah today. Oryx 11:141-191.

11. Galdikas, B.M.F. 1982. An instance of tool-use among wild orang-utans in tanjung puting reserve, Indonesian Borneo. Primates 23(1):138-139.

12. Feeding Ecology in Apes and Other Primates: Ecological, Physiological and Behavioural Aspects. Ed. Hohmann, G., Robbins, M.M., Boesch, C. 2006. Cambridge University Press. [Summit]

13. Primate Info Net (http://pin.primate.wisc.edu/factsheets/entry/orangutan/behav) -- This is a good source of information on a wide variety of topics about orangutans.

Images

1. Male Orangutan: www.bio.miami.edu/dana/pix/orangutan.jpg

2. Orangutan with tool: http://spot.colorado.edu/~humphrey/fact%20sheets/orangutan/images/orangutan_photo.jpg

3. Orangutan Feeding: http://www.fas.harvard.edu/~gporang/rob_in_baccaurea.jpg