Vocalization before grooming interactions in Japanese macaques

Abstract

Japanese macaques, Macaca fuscata, often utter girneys and 'short low' coos when they begin grooming interactions. In a captive group of Japanese macaques, instances of grooming of others by females were compared to cases in which they received grooming with regard to kinship and dominance relations. For unrelated females, dominant females vocalized more frequently when they received grooming than when they groomed subordinates. In contrast, subordinate females vocalized more frequently when they groomed a dominant female than when they received grooming. However, even when each case was examined individually, grooming was not consistently preceded by vocalizations. Generally, females uttered these vocalizations more frequently to unrelated females than to related females. On the other hand, solicitation of unrelated dominant females was infrequent. These results suggest that grooming partners and roles in grooming do not always determine the pattern of vocalization; instead, female monkeys may utter these vocalizations to reduce tension.