ABSTRACT. Demographic and reproductive data were analyzed for a period of 28 years in the females of a free-ranging group of Japanese macaques at Katsuyama, Okayama Prefecture, Japan. The overall mean, age-specific fecundity rates were 5.43% for 4-year-olds and 41.86% for 5-year-olds, increasing to a peak of 66.67% for 13-year-olds. Fecundity remained relatively high (52.31 -54.24%) in 16-19-year-olds, but decreased sharply (45.45 -17.86~ in 20-23-year-olds, and became very low in 24-26-year-olds. Females aged 27 years or more did not produce infants. The average age at first birth was 5.41 years. Births peaked in mid-May. The timing of the first births each year remained essentially unchanged during the study period, whereas the timing of the median and last births shifted towards the later part of the season. The mean interbirth interval for all females was 1.56 years. The value was 1.54 years for multiparous females and 1.29 years for females following infant loss. These intervals were significantly shorter than those for primiparous females, and females with surviving infants. The overall mean infant mortality within the first year of life was 10.2%. The value was 8.6% for 10-14-year-olds, and 7.5% for 15-19-year-olds. The timing of birth differed among the four female matrilineal dominance rank-classes. The female fecundity rates increased as a function of matrilineal dominance rank. It is suggested that all demographic and reproductive data should be analyzed in detail with respect to the group's history.
Dominance relations among adult females in the Katsuyama group of Japanese monkeys (Macaca fuscata) were analyzed. Dominance relations among female relatives of 6 or more years of age corresponded almost exactly to those predicted by Kawamura's principles [Primates, 1:149-156,19581 in the four highest-ranking kin-groups. According to these principles, 1) a mother is dominant to her daughter and 2) among sisters, the younger is dominant to the older. However, 9 of the remaining 11 middleand low-ranking kin-groups included dyads in which dominance relations did not correspond to those expected from Kawamura's principles. Within the dominance rank order, of all 74 adult females of 6 or more years of age, individuals of the high-ranking kin-groups always ranked adjacent to members of their own kin-group, while individuals in middle-and lowranking kin-groups tended to be ranked independently of members of their own kin-groups. These results indicate that, since females of a high-ranking kin-group form a cohesive matrilineal unit, it may be very difficult for females of other kin-groups to break into the dominance rank order that exists among females of the high-ranking kin-groups. o 1995 Wiley-Liss, Inc.
ABSTRACT. This report documents the social interactions among adult Japanese macaques in a free-ranging troop before and after the death of the alpha male, who died at 28 years of age after occupying his rank position for 17 years. The alpha male's physical condition had deteriorated due to his extreme age for several months before his death. However, he maintained his alpha position. When he was attacked by the second-ranking adult male, he was rescued by the alpha female. Thereafter, whenever the second-ranking male approached him, the alpha male screamed for the alpha female's support. The number of adult females to whom the alpha male maintained proximity during his last four months was similar to that during the same period of the previous year. Prior to his death, the alpha male was observed in close proximity to the alpha female much more frequently than was the second-ranking male. These results indicate that the alpha male maintained his position by depending on female support and particularly that of the alpha female.
ABSTRACT. Parturition behavior of a multiparous female and her interactions with group members throughout the birth process were recorded for a free-ranging Japanese monkey (Macaca fuscata).The female showed evidence of 18 contractions during the 35 min prior to delivery, with a mean duration and a mean intercontraction interval of 30 sec and 96 sec, respectively. These values were similar to those in individually caged Japanese monkeys. Some adult females remained in proximity to the female who was giving birth during the prepartum phase, and her 2-year-old daughter watched the delivery of the infant. Even during the prepartum phase the female moved in order to keep up with the group which traveled from the feeding site to a sleeping site in the forest.
The playmate relationships of immature Japanese monkeys were analyzed with respect to age, sex, and dominance rank class of the matrilines in a larger-sized free-ranging group.One-year-old immature males showed the largest number of play partners and the highest frequency of social play. Older immature females tended to play with younger animals of both sexes, whereas immature males of all ages played with same-sexed and like-aged peers. While high-ranking immature males continued their play partnerships with other animals until 4 years of age, middle/low-ranking males did not. The large number of peers and possible play partners may intensify their selectivity of play partners in relation to dominance. The forming of playmate networks by high-ranking immature males may explain the delay in group shifting of high-ranking animals.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.