映像アーカイブを用いたニホンザルにおける稀にしか見られない行動に関するアンケート調査結果報告： 個体群の文化的変異に焦点を当てて

抄録

A web-based questionnaire of infrequently observed behaviors (IOBs) in Japanese macaques (Macaca fuscata) referring to their video footage is administered to primatologists. The first aim was to confirm that the questionnaire methodology had improved relative to that of conventional paper-based questionnaire. The main aim is to extract inter-population differences that could be considered cultural by focusing on IOBs that can be seen in one population but not in another. Participants were asked to report whether they had observed 99 candidate IOBs by answering “yes,” “no,” or “impossible to answer because of ambiguous memory or lack of awareness of the behavior.” In total, 62 answer sheets were returned. As expected, the percentage of “impossible to answer because of lack of awareness” among all respondents decreased due to the use of video footage. Following the percentage of respondents answering “yes” to all giving definite answers (“yes” or “no”), each population was classified as frequently seen (100% ≥ p > 75%), seen (75% ≥ p > 0%), or never seen (0%). The behaviors that were seen in only one population but never seen in others cannot be called cultural yet, as they are not likely to have spread to an extent that could be considered habitual; instead, they should be regarded as innovations of behavior. The following behaviors were extracted: rump–rump contact between males, detachment of branches for branch-dragging social play, and pulling the hair of a female’s chin as courtship by a male. Behaviors that were never seen in at least one but were frequently seen in at least one population, and seen in others, and cannot be explained by environmental differences, can be considered cultural. The following behaviors were extracted: embracing behaviors and stone-handling, both of which have known cultural variations, as well as spitting allo-grooming, spitting self-grooming, self-wrist biting, and breaking-bubbles solo play.