Captive Group Of Japanese Macaques Research Articles

Postconflict Affiliation Among Bystanders in a Captive Group of Japanese Macaques (Macaca fuscata)

Social animals benefit from group living. However, competition for limited resources may lead to agonistic conflicts. These conflicts can affect the behavior and the social relationships, not only of the individuals involved in the confrontation, but also of bystanders. The aim of this study was to describe postconflict affiliative interactions among bystanders (quadratic affiliation) in a captive group of Japanese macaques (Macaca fuscata) and test whether 1) after observing a conflict bystanders tend to interact with other bystanders, 2) conflicts increase bystanders’ rates of self-directed behaviors (SDBs), 3) postconflict rates of SDBs mediate affiliative interactions between bystanders, and 4) quadratic affiliation decreases rates of SDBs to baseline levels. We used the postconflict matched-control (PC-MC) method (5 min focal samples) to record bystanders’ behavior (156 PC-MC pairs from 15 subjects). Results show that bystanders’ rates of SDBs increased above baseline levels after conflicts. Bystanders responded to conflicts by increasing affiliation with other bystanders (mainly with close associates) but not with former combatants. After quadratic affiliation, rates of SDBs decreased to baseline levels. Together with previous findings, these results support the idea that quadratic affiliation is a tension reduction mechanism in less tolerant species.

Successive aggression: another pattern of polyadic aggressive interactions in a captive group of japanese macaques

Several patterns of polyadic aggressive interactions have been previously reported. Here, we describe another pattern of polyadic interactions in a captive group of Japanese macaques (Macaca fuscata fuscata) that we designate as "successive aggression". We defined successive aggression as aggression by the original actor toward a second recipient within a very short time interval after the initial aggression toward the first recipient. We compared the patterns and characteristics of successive aggression to those of redirection. Among 2,698 recorded aggressive interactions, 80 involved successive aggressions and 75 were classified as redirections. Females, especially adult females, performed and received more successive aggression, whereas males, especially adult males, performed and received more redirection. Successive aggression often occurred when the first recipient exhibited counter-aggression. Successive aggression was then directed toward an individual related to the first recipient, such as the mother, offspring or sibling. The targets of redirection were not relatives of the first recipient in most cases, but were clearly subordinate individuals. The dominance relationships among the aggressor, the first recipient and the second recipients were usually non-linear for successive aggression, but were linear for most cases of redirection. These results suggest that monkeys can anticipate possible opponents who may intervene in ongoing aggressive interactions and suppress them, even though they are not yet hostile toward these individuals. Successive aggression may function to establish and maintain dominance relationships among matrilineal groups through repeated confirmations.

Grooming and aggression in captive Japanese macaques

This study investigated the relations between allogrooming and aggression in a captive group of Japanese macaques (Macaca fuscata). Our aim was to test whether evidence of an interchange between allogrooming and a reduction in aggression could be identified at a group level. Female Japanese macaques did not direct less aggression to those group mates that groomed them most. Although generally they did not direct more grooming to those group mates that attacked them most, they did show increased grooming towards those nonkin group mates that showed the most aggression. These results are interpreted in light of the conflicting processes that are likely to underlie macaque social choices.

Variability in behavior frequencies and consistency in transactions across seasons in captive Japanese macaques (Macaca fuscata)

AbstractConsistent interspecific differences are found in macaque species, ranging from highly hierarchical and nepotistic societies to more tolerant and open social organizations. It still remains to be demonstrated whether intraspecific variation is narrower than interspecific variation. Herein, we quantified social behavior in a captive group of Japanese macaques (Macaca fuscata) to estimate the range of intraspecific variation for a full array of measurements in three different seasons. Despite an increased frequency of aggression found on the part of males during the mating season, the form of the behaviors performed remained relatively unchanged. Transactions during conflicts, approaches, or grooming did not undergo significant variations in relation to season. Frequencies and durations seemed more sensitive to demographic and environmental variations. The values measured in the study group are representative of the Japanese macaque. The results validate the use of transaction measurements in interspecific comparisons, providing that additional factors such as age and sex are taken into account. Aggr. Behav. 29:81–93, 2003. © 2003 Wiley‐Liss, Inc.

Vocalization before grooming interactions in Japanese macaques

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.

Female mating strategy in an enclosed group of Japanese macaques.

Female Japanese macaques (Macaca fuscata) are noted for mating with multiple males and for their ability to exert mate choice. In a captive group of Japanese macaques housed at the Primate Research Institute of Kyoto University, Japan, behavioral and endocrine data were combined to examine female mating strategies. During one breeding season, daily behavioral observations were conducted on females who exhibited copulatory behavior. Blood was collected from females twice weekly and their ovulatory periods estimated by analyzing hormone profiles. Females began mating shortly before ovulation, peaked at ovulation, and continued receiving ejaculations for up to ten weeks after conception. Females were more responsible than males for inbreeding avoidance with matrilineal kin. Males sometimes approached females from their own matriline, but females avoided such males and expressed mate choice behavior preferentially toward non-matrilineal males. Over the entire mating season, females did not choose non-matrilineal males on the basis of displays, dominance rank, age, weight, or weight change during the mating season. When females were likely to conceive, however, they expressed mate choice behavior toward males who displayed most frequently. Female mating strategy may include both mate choice at ovulation and other, non-procreative functions.

Female orgasm rate increases with male dominance in Japanese macaques

Under specific circumstances, nonhuman primate females may experience orgasm. The occurrence of female copulatory orgasm appears to be highly variable, however, and its proximate causation is poorly understood. We investigated the proximate mechanisms that control orgasmic response in female macaques. During 238h of observation of sexual behaviour in a large captive group of Japanese macaques,Macaca fuscata, 240 copulations were recorded involving 68 different heterosexual pairs formed by 16 males and 26 females. Female orgasmic responses were observed in 80 of 240 copulations (33%). The frequency of orgasms was not correlated with female age or dominance rank, but it was higher for copulations lasting longer and involving a higher number of mounts and pelvic thrusts. When the level of physical stimulation experienced by females during copulation was statistically controlled, the highest frequency of female orgasms was found among pairs formed by high-ranking males and low-ranking females and the lowest frequency among pairs formed by low-ranking males and high-ranking females. These findings suggest that the proximate mechanisms that control orgasmic threshold in female macaques are more responsive to social stimuli and less constrained by physiological limitations than previously thought.

Sexual selection in Japanese macaques II: female mate choice and male–male competition

Mating and reproductive outcomes are the product of the potentially conficting strategies of breeding males and females. In a captive group of Japanese macaques,Macaca fuscata fuscatabehavioural, endocrine and genetic data were combined to assess the independent effects of male–male competition and female mate choice on mating and reproductive success. Males were ranked by social dominance and by their attractivity to females. Computer simulation and logistic regression analyses showed that male attractivity had a stronger effect than male dominance on both mating and reproductive outcome. Although male dominance and attractivity both significantly predicted mating success during fertile periods, only male attractivity significantly predicted actual male reproductive success. These results provide evidence that female mate choice can be a stronger determinant of mating and reproductive outcome in this species when male and female strategies are in conflict. The lack of a consistent correlation between male dominance rank and reproductive success in this species may be accounted for in part by female mate choice of socially subordinate males. Sires who were observed to mate with the mother during her fertile period were more likely to be socially dominant than sires who were not observed to do so. This observation suggests the existence of alternative mating strategies by subordinate males, which may also contribute to the lack of a consistent correlation between male dominance rank and reproductive success in this species.

Competing through Co-operation in Nonhuman Primates: Developmental Aspects of Matrilineal Dominance

This paper's major aim is to illustrate how competition and co-operation are causally interrelated in the social life of nonhuman primates. In many species, competition for resources and mates commonly leads to xenophobic alliances and to the formation of intra-group dominance orders in which coalitions and alliances play a major role. In this sense, competition fosters co-operation. After briefly reviewing the nature of alliances in primates, this paper focuses on matrilineal dominance systems, which characterise many species of the Cercopithecidae family (macaques, baboons, etc.). In these societies, females socially inherit their mother's rank above lower-ranking matrilines with the result that kin rank next to each other. This paper summarises 10 years of experimental research on the composition and dynamics of alliances in a captive group of Japanese macaques (Macacafuscata). The main experimental paradigm consisted in manipulating the composition of the group, thereby dismantling existing alliances and inducing the formation of new alliances and new rank orders. Results reveal the existence of a complex interplay of kin and nonkin alliances responsible for the acquisition of rank and, later, for the maintenance of rank relations within and between kin groups. Opportunistic, selfishly motivated interventions in conflicts, performed by juveniles sharing the same targets (common targeting principle), appear to account for the initial formation of alliances in these dominance systems and, possibly, in various other situations as well. Such relatively simple processes may have paved the way for ontogenetically and phylogenetically more sophisticated forms of co-operation, such as reciprocity involving delayed benefits to the donors.

Dominance competition through affiliation and support in Japanese macaques: An experimental study

It has been proposed that monkeys direct grooming to high-ranking individuals in an attempt to obtain agonistic support in return. But whether these two categories of interactions are causally related has proven difficult to establish. Part of the problem stems from the fact that in stable groups social relationships reflect an equilibrium state and that behaviors need only be performed at low rates and long intervals to maintain the current social structure. In theory, however, if affiliative and supportive interactions are indeed causally related, it should be possible to accentuate their temporal relation, hence their causal dynamics. For example, destabilizing dominance relations can be expected to induce competition for status and force individuals to deploy behavioral tactics for settling new rank relations. We experimentally induced rank reversals in a captive group of Japanese macaques (Macaca fuscata) composed of three matrilines (A-B-C rank order). A reversed C-A-B order composed of three individuals per matriline was maintained for 2 weeks. The results show the close temporal relation among (i) asserting one’s rank, (ii) competing for access to dominants through affiliation and interferences in affiliation, (iii) receiving support from dominants against lower-ranking individuals, and (iv) supporting dominants against subordinates. These findings are compatible with one version of the affiliation-for-support hypothesis, namely that monkeys affiliate with dominants as a way to assert their position in the hierarchy. In a functional perspective, mutual selfishness provides a better explanation than reciprocal altruism because the possibility that both groomers and supporters derive immediate net benefits cannot be excluded.

Dominance style of Japanese macaques compared with rhesus and stumptail macaques.

In the present study, we seek to relate dominance style with group cohesion in a captive group of Japanese macaques (Macaca fuscata). Social data were gathered on approach rate, result, and direction, aggression rate and intensity, grooming rate and direction, and conciliatory tendency. Data were collected using focal animal sampling and instantaneous scan sampling. Reconciliation data were collected using ad libitum observations of aggression with ten-minute post-conflict and matched-control focal observations. Data were compared to prior studies on rhesus (M. mulatta) and stumptail macaques (M. arctoides) living in similar environments. Each species demonstrated the presence of a formalized dominance hierarchy based on the teeth-baring display. The Japanese macaque group showed a lower rate of approach with a higher proportion of negative outcomes than either of the other species. Rates of aggression and reconciliation were also lower in the study troop, suggesting a strict hierarchy while maintaining an optimal nearest-neighbor distance. Overall, this group of Japanese macaques was less sociable than other groups of the same species, perhaps due to a history of individual removals. © 1995 Wiley-Liss, Inc.

Japanese macaque microsatellite PCR primers for paternity testing

Capture and blood sampling in wild primate populations are difficult. For this reason, we need to use DNA extracted from the hair or feces of target animals. The polymerase chain reaction (PCR) method, which amplifies small volumes of DNA, provides an ideal means for studying DNA variations in wild populations. Three sets of PCR primers which amplify highly polymorphic (GT/AC)n dinucleotide repetitive regions were synthesized from DNA sequences of Japanese macaques (Macaca fuscata). One of the primer pairs detected at least seven alleles in one captive Japanese macaque group. Also, the fathers of four offspring whose mothers had died in a captive group of Japanese macaques were identified. In such cases, the father cannot be determined by the previous DNA fingerprinting method based on the polymorphism of minisatellite DNA. These primers were further tested with some species of the Cercopithecidae, e.g. grivet monkeys (Cercopithecus aethiops tantalus) and hamadryas baboons (Papio hamadryas). The results obtained suggest that these primers can detect stably inherited polymorphic regions in each species.

Non-kin alliances, and the stability of matrilineal dominance relations in Japanese macaques

Alliances among kin play a major role in a female's acquisition of her mother's dominance rank in many species of cercopithecines. It is noteworthy, however, that kin rarely form coalitions to challenge females from higher-ranking matrilines, and that matrilineal hierarchies are remarkably stable. One possible reason for the rarity of destabilizing coalitions is that members of high-ranking matrilines form alliances against lower ranking ones. In this paper the patterning of aggressive support among non-kin, and its effect on the stability of rank relations are analysed in a captive group of Japanese macaques, Macaca fuscata, composed of three unrelated matrilines. Analysis of the distribution of non-kin interventions in conflicts between matrilines over a 52-month period revealed a clear pattern of preferential support between the two dominant matrilines against the third-ranking one. This pattern was confirmed experimentally. Any member of the two dominant matrilines was unable, individually, to maintain its rank above the third-ranking matriline, but was able to do so in the presence of the other dominant matriline. Non-kin alliances appear to prevent subordinate females from challenging higher ranking females through revolutionary coalitions (formed among subordinates) or through bridging coalitions (formed among individuals ranking above and below the target). Non-kin support is interpreted in terms of cooperation versus reciprocal altruism.

Female sexual behavior in the absence of male‐male competition in captive Japanese macaques (Macaca fuscata)

AbstractA captive group of Japanese macaques (Macaca fuscata). consisting of one adult male and three adult females, was observed for 88 hr during the 1988 mating season. We focused on the group's sexual activities because understanding how social dynamics affect reproductive behavior may enhance our ability to establish self‐sustaining captive populations. The adult male exhibited distinct preferences in copulation partners, although all females were receptive and cycled during the study period. The dominant female participated in the most copulations and successfully harassed and disrupted copulations between the male and the other females. The alpha female, therefore, actively constrained the formation of mating pairs. Further, the male did not consort with his year‐round female grooming partner. This female, the least dominant member of the group, engaged in the most autosexual and homosexual behavior. Birth season data show that only the dominant female bore offspring. This study emphasizes the influence of social dynamics on a group's reproductive potential and suggests an alternative means by which females can influence consort formation.

Homosexual incest avoidance among females in captive Japanese macaques.

This paper reports a systematic pattern of homosexual incest avoidance among females in a captive group of Japanese macaques (Macaca fuscata) culled from the Arashiyama-West troop known for its high rates of female homosexuality. The study group included three matrilines and two generations. Between eight and 11 females were sexually active over four consecutive mating seasons, and all engaged in both heterosexual and homosexual activity. While all females performed homosexual acts with almost all possible non-kin partners, they systematically avoided homosexual interactions with their mother, daughters, and sisters. This pattern could not be explained either in terms of kin not being simultaneously in estrus, kin avoiding affiliative interactions in general, or non-kin utilizing the tension-reducing effect of estrus to affiliate exclusively with each other. In contrast to homosexual females, heterosexual pairs of relatives (brother-sister, mother-son) were sometimes incestuous. Assuming that female homosexuality expresses the reproductive strategy of females unconstrained by male influence, the present results point to the strong tendency of females to avoid incest and suggest that males are primarily responsible for the reported exceptions to incest avoidance.

Rank Maintenance in Female Japanese Macaques: Experimental Evidence for Social Dependency

In many species of cercopithecines characterized by a matrilineal dominance system, a female inherits her mother's rank (genealogical rank) and there is no correlation between a female's genealogical rank and her physical strength. This paper explores the determinants of rank maintenance and rank stability in such systems. Theoretically, a female might be in need of allies to maintain her rank because (1) she could be challenged by single larger females in dyadic agonistic interactions, and/or (2) she could be challenged by smaller or same-size females acting together (rebellious coalitions). A series of experiments designed to test these two possibilities were carried out in a captive group of Japanese macaques (N = 17) comprised of three families with similar age-sex compositions. Experimental subgroups of females were formed to test the capacity of a single female (i. e. with none of her relatives present) to maintain her rank above genealogically subordinate females (G-Subordinate females) in four social situations: (a) with same-age G-Subordinate females; (b) with a single, older G-Subordinate female, (c) with a group of G-Subordinate sisters, and (d) with a complete G-Subordinate family. Sixty seven experimental subgroups were formed, and 45% of these induced genealogical rank reversals. Low-ranking females appeared to be conditional opportunists who competed for rank only in situations where they clearly had more relative power than the single G-Dominant female (minimal risk strategy). In the experimental subgroups where a G-subordinate female was by herself (no kin present: situations a and b above), she challenged a single G-Dominant female only if the latter was younger and smaller than herself, and she did so only if the G-Dominant female was immature ( 3). Thus, single G-subordinate females did not challenge single same-age G-Dominant females nor did they even challenge single younger G-Dominant females if the latter were mature. In contrast, in the experimental subgroups comprised of a G-Subordinate kin group (situations c and d above), G-Subordinate females could challenge collectively, and outrank, single G-Dominant females, regardless of the latter's age (size). One important implication of these findings is that any female, regardless of her age, is dependent on allies (sensu KAWAI, 1965) to maintain her rank. Thus the hierarchy's stability in matrilineal dominance systems would reflect the existence of inter-individual differences in alliance power, such that for any dyad the G-Dominant female has more collective power than the G-Subordinate female. Two categories of mechanisms are discussed in this context. Stability might result from the dynamics of intra-familial alliances (power asymmetry or power equality among kin-based coalitions) and/or from the dynamics of inter-familial alliances (asymmetry of inter-familial dependence).

A further food-washing tradition in Japanese macaques (Macaca fuscata)

A case of food-washing tradition is reported in a captive group of Japanese macaques. Two techniques are employed, with one or both hands being used to wash food under water flowing from watering spouts. Processes of diffusion of the behaviour in the group follow the patterns previously described by Japanese scientists observing this species. It is suggested that development of such a behaviour could be related to particular environmental conditions.

Interbirth intervals in a captive group of Japanese macaques.

Interbirth intervals in a captive group of Japanese macaques were found to be shortened and inconsistently affected by stillbirth and infant loss within 6 months of life. The reduction in the length of the interval between successive births was in all probability the result of shorter periods of lactation and larger amounts of body fat stored by the well-nourished females of the study group.

Alopecia in a Captive Group of Japanese Macaques (Macaca fuscata)

Alopecia in a Captive Group of Japanese Macaques (Macaca fuscata)