|| 要旨トップ | 目次 |||日本生態学会第68回全国大会 (2021年3月、岡山) 講演要旨
一般講演（口頭発表） H01-07 （Oral presentation）
The dietary shift from mother’s milk to solid foods is the common challenge for all mammals. Some neotropical primates are known to fill the gap by the frequent food transfer from caregivers to infants. The importance of food transfer should be high especially for primates in the subfamily Pitheciinae which is recognized as “seed eater”, because of their extractive foraging style requiring manual dexterity, robust teeth, and powerful jaws. However, little is known about their food transfer or the developmental process of the feeding behavior. We observed two free-ranging groups of Golden-faced Saki (Pithecia chrysocephala) in Manaus, Brazil. Through 908 hours of observation, we recorded 398 food transfer events. All events were initiated by juveniles' begging and no proactive food offerings was observed. Among them, 52% of the begging were by 4 individuals of 0-year-old, and 48% were by 7 individuals of 1-year-old. The begging frequency was not different between 0-year-old and 1-year-old, but the success rate of the begging was higher in 1-year-old. The diversity of begged fruits was less in 1-year-old. They begged more frequently for fruits that require longer handling time. These results suggested that older juveniles were begging more selectively to optimize their food-intake efficiency.