Food transfer between chimpanzee mothers and their infants
- 333 Downloads
Food sharing among chimpanzees is known to occur particularly between mothers and infants and has been proposed to be a form of parental investment. To explore the function of food sharing, it is essential to know how and what is transferred to an infant from its mother. We investigated details of interactions leading to food transfer and characteristics of items transferred in three mother–infant (<2 years old) pairs in captivity. We gave one kind of fruit or vegetable to a mother and observed interactions between the mother and her infant. Tested items consisted of familiar and novel foods for infants. Two patterns of direct food transfer, so-called sharing, were recognized: (1) “infant-initiated sharing” in which the infant attempted to take food and the mother did not resist, and (2) “mother-initiated sharing” in which the mother spontaneously offered a part of her food without the infant’s attempts to take it. There were clear differences in the characteristics of items transferred in these two patterns of sharing. In infant-initiated sharing, palatable parts of the same food that the mother was eating were transferred. In contrast, in mother-initiated sharing, only unpalatable parts of food in the mother’s possession were transferred. Mothers seemed to be reluctant to give nutritious foods to their infants during this study period. Infants, rather than mothers, were responsible for initiating and experiencing the diversity of adult foods in chimpanzees.
KeywordsFood transfer Food sharing Mother–infant Chimpanzee
Video clip of a trial with Ai and Ayumu which was recorded by two video cameras outside and inside an experimental booth.
ESM1 An infant (Ayumu) approached green pepper held by his mother (Ai), extended his hand, pulled it toward his mouth, and then infant-initiated sharing occurred (corresponding to Fig. 1a).
(MPEG 5.9 MB)
ESM2 Ai offered a fig skin to Ayumu after she had chewed it up, and then mother-initiated sharing occurred (corresponding to Fig. 1b).
(MPEG 2.8 MB)
- Goodall J (1986) The chimpanzees of Gombe: patterns of behavior. Harvard University Press, Cambridge, Mass.Google Scholar
- Hiraiwa-Hasegawa M (1990a) A note on the ontogeny of feeding. In: Nishida T (ed) The chimpanzees of Mahale mountains. Tokyo University Press, Tokyo, pp 279–283Google Scholar
- Hiraiwa-Hasegawa M (1990b) Role of food sharing between mother and infant in the ontogeny of feeding behavior. In: Nishida T (ed) The chimpanzees of Mahale mountains. Tokyo University Press, Tokyo, pp 267–275Google Scholar
- King BJ (1994) The information continuum—evolution of social information transfer in monkeys, apes, and hominids. School of American Research Press, Santa Fe, N.M.Google Scholar
- Lefebvre L (1985) Parent–offspring food sharing: a statistical test of the early weaning hypothesis. J Hum Evol 14:255–261Google Scholar
- McGrew WC (1975) Patterns of plant food sharing by wild chimpanzees. In: Kondo S, Kawai M, Ehara A (eds) Contemporary primatology. Karger, New York, pp 304–309Google Scholar
- Nishida T, Turner L (1996) Food transfer between mother and infant chimpanzees of the Mahale mountains national park, Tanzania. Int J Primatol 17:947–968Google Scholar
- Nissen H, Crawford M (1936) A preliminary study of food-sharing behavior in young chimpanzees. J Comp Psychol 22:383–419Google Scholar
- Plooij FX (1984) The behavioral development of free-living chimpanzee babies and infants. Ablex, Norwood, N.J.Google Scholar
- Ueno A, Matsuzawa M (2003) Mother–infant interactions over foods and food sharing. In: Tomonaga M, Tanaka M, Matsuzawa T (eds) Cognitive and behavioral development in chimpanzees—a comparative approach (in Japanese). Kyoto University Press, Tokyo, pp 243–247Google Scholar