Grooming relationships of adolescent orphans in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama: a comparison among orphans with sisters, orphans without sisters, and females with a surviving mother

Abstract

The present study examined grooming relationships of adolescent females in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama. To assess whether the loss of the mother influenced the grooming relationships of adolescent females (5-7 years old), we compared the time spent in grooming interactions and the number of grooming partners among the following three groups: 6 adolescent orphans with sisters, 9 adolescent orphans without sisters, and 11 adolescent non-orphans with surviving mothers. In Japanese macaques, grooming most frequently occurs between mothers and their daughters. Therefore, it is expected that if the mother is lost, orphans will devote less time to grooming interactions than non-orphans. However, the time spent in overall grooming interactions did not differ among the three groups. While non-orphans maintained grooming relationships with their mothers, orphans acquired alternative grooming relationships with other group members. Orphans adopted two kinds of tactics to compensate for the loss of the mother. First, adolescent orphans with sisters developed more affiliative grooming relationships with their sisters than non-orphans with sisters. Secondly, adolescent orphans without sisters spent more time in grooming interactions with same-aged females and non-related adult females. Moreover, regarding grooming interactions with same-aged females and non-related adult females, orphans without sisters had a larger number of grooming partners than non-orphans. These results indicate that adolescent females have enough flexibility to develop their grooming network after the loss of their mothers, and that the lack of mother and sisters might accelerate socialization of adolescent females and enable them to be integrated in reciprocal adult grooming relationships.

Disability, Compensatory Behavior, and Innovation in Free‐Ranging Adult Female Japanese Macaques (Macaca Fuscata)

“…On the other hand, Lemur catta with dental impairment, engaged in more feeding time during a period of the day when others tended to rest [Millette et al, 2009]. Hands are normally used to perform many life-sustaining activities; in addition to feeding and climbing, hands are usually used for both auto and allogrooming, behaviors that are important socially and in terms of reduction of ectoparasite burdens [Nakamichi and Shizawa, 2003;Tanaka, 1995;Tanaka and Takefushi, 1993;Yamada et al, 2005]. Furthermore, physical impairment has potential consequences for locomotor ability.…”

“…CLMs can affect manual functionality, dexterity, and the ability to grasp objects. Hands are normally used to perform many life-sustaining activities; in addition to feeding and climbing, hands are usually used for both auto and allogrooming, behaviors that are important socially and in terms of reduction of ectoparasite burdens [Nakamichi and Shizawa, 2003;Tanaka, 1995;Tanaka and Takefushi, 1993;Yamada et al, 2005].…”

A novel methodological approach for group classification during fission of a semi‐free‐ranging group of Japanese macaques (Macaca fuscata)

“…To analyze the degree of kinship across the newly formed groups, we assessed the closest living relative of each individual (Table 2 ). Which individual was regarded as the closest living relative was based on the care providing function during the ontogeny of infants and juveniles in Japanese macaques (MacDonald Pavelka et al, 2002 ; Nakamichi, Onishi et al, 2010 ; Nakamichi & Yamada, 2010 ; Nozaki, 2009 ; Yamada et al, 2005; 2005 ). If the mother of a male was still alive, she would be the closest care‐providing relative and therefore included in this analysis.…”

Grandmothers care for orphans in a provisioned troop of Japanese macaques (Macaca fuscata)

“…At Takasakiyama, according to Itani (1959), high-ranking adult males cared for infants during the birth season. On the other hand, at Katsuyama, Yamada et al (2005) found that adolescent orphans without sisters spent more time grooming with same-aged females as well as other unrelated adult females.…”