Visual preference in a human-reared agile gibbon (Hylobates agilis)
- 196 Downloads
Visual preference was evaluated in a male agile gibbon. The subject was raised by humans immediately after birth, but lived with his biological family from one year of age. Visual preference was assessed using a free-choice task in which five or six photographs of different primate species, including humans, were presented on a touch-sensitive screen. The subject touched one of them. Food rewards were delivered irrespective of the subject’s responses. We prepared two types of stimulus sets. With set 1, the subject touched photographs of humans more frequently than those of other species, recalling previous findings in human-reared chimpanzees. With set 2, photographs of nine species of gibbons were presented. Chimpanzees touched photographs of white-handed gibbons more than those of other gibbon species. The gibbon subject initially touched photographs of agile gibbons more than white-handed gibbons, but after one and two years his choice patterns resembled the chimpanzees’. The results suggest that, as in chimpanzees, visual preferences of agile gibbons are not genetically programmed but develop through social experience during infancy.
KeywordsAgile gibbon Sensory reinforcement Visual preference Social experience
The first author has now moved to the Wildlife Research Center, Kyoto University. This study was financially supported by MEXT Grants-in-Aid for Scientific Research (Nos. 20002001, 19530653), the Global COE Programs A06 and D07 to Kyoto University, and a research fellowship to M. Uchikoshi from JSPS (No. 171163). We thank the members of the Language and Cognition Section of KUPRI for technical assistance and encouragement. We also thank the staff members of the Center for Human Evolution Modeling Research, KUPRI, for taking care of the subjects’ health.
- Brockelman WY, Gittins SP (1984) Natural hybridization in the Hylobates lar species group: implications for speciation in gibbons. In: Preuschoft H, Chivers DJ, Brockelman WY, Creel N (eds) The lesser apes. Evolutionary and behavioral biology. Edinburgh University Press, Edinburgh, pp 498–532Google Scholar
- Gittins SP (1978) Hark! The beautiful song of the gibbon. New Sci 80:832–834Google Scholar
- Marshall JT, Sugardjito J (1986) Gibbon systematics. In: Swindler DR, Erwin J (eds) Comparative primate biology, vol 1: systematics, evolution, and anatomy. Alan R. Liss, New York, pp 137–185Google Scholar
- Mather R (1992) A field study of hybrid gibbons in central Kalimantan, Indonesia (Ph.D. thesis). Department of Veterinary Anatomy, Cambridge University, CambridgeGoogle Scholar
- Matsuzawa T, Tomonaga M, Tanaka M (eds) (2006) Cognitive development in chimpanzees. Springer, TokyoGoogle Scholar
- Uchikoshi M, Matsuzawa T (2002) Behavioral development of agile gibbons: the first four years after birth (in Japanese with English summary). Jpn Psych Rev 45:483–499Google Scholar
- Uchikoshi M, Matsuzawa T (2007) Tooth eruption in two agile gibbons (Hylobates agilis). Gibbon J 3:66–73Google Scholar