抄録
Eight mother-young pairs of free ranging Japanese macaques, sampled equally from two groups and divided in two set of young (weaned infant less than one year old and juveniles aged between 1.5 and 2 years old), were followed during three months in winter 2005-2006. I systematically recorded the intense behavioural observation directed toward elder by young of the two age-classes, the items manipulated by the elder and closely observed and the immediate post-behaviour displayed by young as well as the items or the location explored. Moreover, I estimated the mothers and juveniles diet from the proportion of occurrences for each food items ingested and from the quantity of fresh matter ingested. It appeared that the intense behavioural observation of both infants and juveniles were directed toward elders engaged in a feeding behaviour on the main food items (mainly fruit, seed) or in an insect foraging behaviour. Infants exhibited the intense behavioural observation more frequently than juveniles. They also showed the intense observational behaviour toward elder other than their mothers, while juveniles did not. Moreover, after having paid an attentive attention the elder's foraging behaviour, infants displayed the same behaviour as the elders and that more frequently than juveniles. These results match the juveniles-adult dependent model of social transmission of information described by King (2005). Furthermore, the intense behavioural observations relevant of late infant stage corresponded to the phase of transition between a milk diet and a solid diet and might be certainly considered as a behavioural process to obtain information about critical survival skills as edible and rich-food in sugar, lipid and protein selection and location.
