van Schaik CP, M. Ancrenaz, G. Borgen, B. Galdikas, C.D. Knott,
I. Singleton, A. Suzuki, S. Utami, M. Merrill (2003) Orangutan
cultures and the evolution of material culture. Science 299(1):
102-105.
van Schaik CP, Fox EA, and Sitompul AF (1996) Manufacture
and use of tools in wild Sumatran orangutans. Naturwissenschaften
83:186-188.
van Schaik CP (1999) Fission-fusion sociality in Sumatran
orangutans. Primates 40: 73-90.
Fox EA, Sitompul AF, and van Schaik CP (1999) Intelligent
tool use in wild Sumatran orangutans. In ST Parker, HL Miles and
RW Mitchell (eds.): The Mentality of Gorillas and Orangutans.
Cambridge, UK: Cambridge University Press.
van Schaik CP, Deaner R and Merrill M (1999) A primate
model for the evolution of material culture. Journal of
Human Evolution June 1999
van Schaik CP, Azwar, and Priatna D (1995) Population estimates
and habitat preferences based on line transects of nests. In RD
Nadler, BFM Galdikas, LK Sheeran and N Rosen (eds.): The Neglected
Ape. New York: Plenum Press, pp. 129-147.
You can see an orangutan from Suaq Balimbing make and use a tool
with a Neesia sp. fruit by downloading this 2MB video.
To learn more about the illegal logging situation at Suaq, you may
wish to read or see the following:
