Conflict and postconflict behaviour in captive black-and-white snub-nosed monkeys (<Emphasis Type="Italic">Rhinopithecus bieti</Emphasis>)

Black-and-white snub-nosed monkeys (Rhinopithecus bieti) have almost never been the subject of any behavioural observations in captivity. This study was aimed at providing preliminary information about agonistic and reconciliation behaviour in a group kept at the Kunming Institute of Zoology in China. Established procedures were used for this investigation (i.e., the postconflict/matched-control method and the time-rule method). Intra-group aggression rates were quite low. Postconflict affiliation as well as selective attraction of former opponents to each other following conflicts was demonstrated. Former opponents contacted each other earlier in postconflict periods than in matched-control periods. The average conciliatory tendency of all focal individuals combined was 54.5%. After an agonistic interaction, the first affiliative contact between former aggressors usually took place within the first minute. The behaviours most often shown as first affiliations after a conflict were body contact, mount, touch, and hold-lumbar, of which the latter is an explicit reconciliatory gesture. Furthermore, the adult male intervened non-aggressively in 84% of all conflicts (n=25) among the adult females. Overall, the patterns of aggression and reconciliation observed in R. bieti bear many of the traits that characterise tolerant primate species.     

Reconciliation, consolation and postconflict behavioral specificity in chimpanzees

Conflicts of interest arise regularly in the lives of all group-living animals and may escalate into aggressive conflicts. The costs of aggressive escalation can be reduced through peaceful postconflict interactions. This study investigated the postconflict behavior of 22 adult chimpanzees at Chester Zoo. The occurrence of reconciliation, i.e. the postconflict affiliative reunion between conflict opponents, and consolation, i.e. a postconflict affiliative interaction directed from a third party to the recipient of aggression, were demonstrated. Consolation was more likely to occur in the absence of reconciliation than after reconciliation, and reconciliation was more likely to occur in the absence of consolation than after consolation, supporting the hypothesis that consolation acts as a substitute for reconciliation when the latter fails to occur. Evidence for behavioral specificity, i.e. context-specific use of certain behaviors, was found for both reconciliation and consolation, which, along with high conciliatory tendencies, suggests an explicit style of postconflict behavior in the study subjects.     

Postconflict Behavior of Spectacled Leaf Monkeys (Trachypithecus obscurus). II. Contact with Third Parties

We studied the postconflict interactions with group members other than the former opponent in two groups of spectacled leaf monkeys. We found no evidence of redirection of aggression towards other group members. Victims and aggressors sought affiliative contacts with uninvolved third parties. There was no evidence for consolation—affiliative contact initiated by an uninvolved third party, directed towards victims of aggression—in either group when all affiliative behaviors were considered. However, embracing was a characteristic first-contact interaction between individuals involved in aggression and third parties. This finding mirrors the results concerning reconciliation in spectacled leaf monkeys. Accordingly, embracing may be a true consolatory behavior in this species. When contacts with third parties occurred before or in the absence of reconciliation, the timing of such contacts fell within the time window during which reconciliation normally occurs. These contacts also resulted in affiliation levels twice that of baseline levels, supporting the idea that these contacts may function as a form of substitute reconciliation. We discuss these results in light of recent theories concerning postconflict behavior in primates.     

Reconciliation and consolation in captive bonobos (Pan paniscus)

Although reconciliation in bonobos (Pan paniscus) has previously been described, it has not been analyzed heretofore by the postconflict (PC) match-control (MC) method. Furthermore, although reconciliation has been investigated before in this species, consolation has not. In this study we analyzed agonistic and affiliative contacts in all sex-class combinations to clarify and reevaluate the occurrence of reconciliation in bonobos via the PC-MC method. We also investigated the occurrence of consolation by analyzing the victims' triadic contact tendency (TCT), the influence of the sex of victims, and the relative occurrence of consolation and reconciliation. We collected 167 pairs of PC-MC observations in a captive group of bonobos (in Apeldoorn, The Netherlands). The conciliatory tendency (CCT) we obtained was tendentially lower than the mean value previously found for Yerkes captive chimpanzees. Close relationships, which were present in all female-female (FF) and some male-female (MF) dyads, positively affected reconciliation rates. When only adult PC-MC pairs (157) were considered, the mean TCTs and CCTs did not differ significantly. When we focused on types of PC affiliative contact, in the case of consolation we found a striking preference for sociosexual patterns. As to the relative occurrence of consolation and reconciliation, the highest level of the former was found in the absence of the latter. When reconciliation took place, consolation generally preceded it, suggesting that consolation may be a substitutive behavior. Our findings suggest that even if reconciliation remains the best option, consolation may be an alternative substitute for reconciliation that is used to buffer the tension originating from an unresolved conflict. Reconciliation and consolation are complex phenomena that are probably related to the life history of a group. Given that few studies have been conducted on this subject, we can not at this time make any generalizations regarding conflict resolution in certain species by comparing results among studies.     

Sleeping cluster patterns and retiring behaviors during winter in a free-ranging band of the Sichuan snub-nosed monkey

Little information is available on the sleeping cluster pattern and retiring behavior of Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Here, we provide observational data on a provisioned free-ranging band in the Qinling Mountains, central China. The results suggest that winter night activity of R. roxellana is a compromise between antipredator and thermoregulatory strategies and an adaptation to ecological conditions of their temperate habitat. Monkeys retired between 1804 and 1858 h in winter. In support of the antipredation hypothesis, all monkeys slept in trees at night, whereas 18.8% of individuals slept on the ground during the day. Also, the study band was more spatially cohesive at night than in daytime, with shorter distances between one-male units. Keeping warm is critical for survival in freezing temperatures. Monkeys often slept in the lower stratum of the tree canopy, avoiding the upper canopy where it is cold and windy. They formed larger sleeping clusters at night than in daytime. The most common types of night-sleeping clusters were adult females and juveniles, followed by adult females with other adult females. These accounted for 60.2% of the total records. The frequency of female–male clusters is two times greater, and that of adult male–juvenile clusters was four times less at night than during the day. The variations in composition of sleeping clusters suggest affiliative patterns at night-sleeping sites differ from those during the day.     

Postconflict affiliative contacts between former opponents among wild moor macaques (Macaca maurus)

Agonistic interactions and postconflict behavior of moor macaques (Macaca maurus) were studied in their natural habitat, South Sulawesi, Indonesia. Individuals were involved in 0.28 agonistic interactions per hour. Forty-two percent of agonistic interactions were followed by affiliative contacts between the former opponents. Such affiliative contacts occurred within 2 minutes of the agonistic interaction and were most often initiated by the victim's approach to the aggressor. The most common postconflict behavior was grooming of the aggressor by the victim. The present study provides further evidence of a positive correlation between a high tendency for postconflict affiliative contact and a relaxed dominance style. Captivity might not alter the expression of postconflict behavior. The present study suggests that it is possible to demonstrate the occurrence of reconciliation a posteriori by using data obtained by general focal observation protocols. © 1996 Wiley-Liss, Inc.     

Social play behavior in infant Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in Qinling Mountains, China

We describe the development of social play behavior and assess factors influencing the development of play in infant Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Infant snub-nosed monkeys began to exhibit social play at 3 months of age, when they spent an average 0.89% of time engaging in this behavior (range: 0.7-1.12%). At 6 months of age, there was a significant increase in the proportion of time spent in social play, averaging 9.78% of observation time (range: 4.92-17.08%). However, from 7 to 9 months of age during the winter, social play decreased gradually before rising again from 10 months of age in the spring. Play behavior in infant snub-nosed monkeys is influenced by environmental temperature. Males were observed to play more than females, although further data on this are required. Social rank did not influence the social play of wild Sichuan snub-nosed monkey infants.     

Terrestrial behavior and use of forest strata in a group of black-and-white snub-nosed monkeys Rhinopithecus bieti at Xiaochangdu,Tibet

Food distribution and predation pressure are considered to be the main ecological factors that influence the use of forest strata(basically arboreality vs.terrestriality)in non-human primates.Here,we investigate ground use of wild,unprovisioned black-and-white snub-nosed monkeys Rhinopithecus bieti by means of the scan sampling method.The results show that the monkeys spent 15.0% of the day time on the ground;16.6%,12.7%,and 15.6% for adult males,adult females and juveniles,respectively.Adult males and juve...     

Do Adult Male Spider Monkeys (Ateles geoffroyi) Preferentially Handle Male Infants?

Infant tolerance by adult males has been observed in many primate species with multimale–multifemale mating systems, but males do not usually initiate interactions with infants. In male philopatric species, such as spider monkeys, adult males within a community exhibit high levels of cooperation and affiliation, and they might therefore be motivated to create bonds with potential future allies. Based on this hypothesis we predicted that adult male spider monkeys would participate in infant handling more than adult females and they would preferentially direct handling toward male infants. Between January 2008 and July 2010, we collected 884?h of observation on a community of wild spider monkeys at Runaway Creek Nature Reserve in Belize. During this period we observed 120 incidences of affiliative interactions between infants and adults other than their mother. The adult initiated the majority of nonmother adult–infant interactions (78?%). All available infants (5 males, 7 females) were handled during the study. All 9 of the community adult males handled infants but only 7 of 14 adult females did so. Adult males handled infants significantly more often than did adult females and males also handled young infants more often than older infants. Significant infant sex differences in handling appeared in infants >6?mo when adult males handled males significantly more than females. The patterns of infant handling among age–sex class dyads reflect the affiliative social patterns that we see in adult spider monkeys. These results provide support for the hypothesis that adult males preferentially handle male infants as a strategy for fostering social bonds.     

Distribution of affiliative behaviors among adult females within a group of wild patas monkeys in a nonmating,nonbirth season

The distribution of four affiliative behaviors (proximity within 3 m, allogrooming, contact calling, and co-night-resting) were examined in a group of wild patas monkeys (Erythrocebus patas) during a nonmating, nonbirth season. To a greater or lesser extent, dominance rank and kinship influenced these behaviors of the adult females. Since high-ranking females tended to exhibit some of these behaviors with high frequency, they were considered to be acting as the focus of affiliative behaviors and as the center for group cohesion. Furthermore, related adult females also tended to exhibit some of these behaviors with a high frequency toward one another, so that matrilineal kinship was also seen to be an important factor for group cohesion. In contrast, the harem male tended to exhibit these behaviors at a low frequency and/or had no affiliative partner for any of them. Thus, it appears that the social organization of the patas group is concentric, being composed of high-ranking females in the center, low-ranking females at the periphery, and the harem male at the distant periphery.     

Female social relationships in a captive group of Campbell's monkeys (Cercopithecus campbelli campbelli)

A study group of Campbell's monkeys (Cercopithecus c. campbelli) provided data on affiliative and agonistic relationships between females. Over a period of two years (involving 111 hr), we conducted observations of a captive group which had a composition similar to wild groups. We were able to identify a monitor-adjust social system with frequent affiliative interactions, directed gazing and avoidances rather than aggressive acts. We described long-term differentiated affiliative bonds: adult females interacting more often with some group mates than others, especially if they were relatives. Interactions between matrilines concerned essentially play and young adult females. We found a significant linear hierarchy of dominance with rare reversals and a stable intermatriline dominance. In contrast to other single-male groups, our adult male was socially integrated into the group although this may have been because of the housing conditions. Comparisons with the social organization of other captive and wild guenon groups are discussed.     

First direct evidence of infanticide and cannibalism in wild snub-nosed monkeys (Rhinopithecus bieti)

Although infanticide has been witnessed in many species of Colobinae, and a case was observed in a captive group of golden snub-nosed monkeys (Rhinopithecus roxellana), observed cases of infanticide in wild snub-nosed monkeys (Rhinopithecus spp.) have not previously been recorded. Here we describe the killing of a 1-month-old infant by a male in a black-and-white snub-nosed monkey (R. bieti) group at Xiaochangdu in Tibet. The infanticidal attack was witnessed as part of a long-term observational study of ecology and behavior that began in June 2003. The male was observed killing and eating the infant. The literature proposes three main explanations for infanticide: two adaptive hypotheses (sexual selection and resource competition), and one nonadaptive hypothesis (social pathology). Individual cases of infanticide, such as this one, are important for comparative purposes, but when examined on their own they are difficult to interpret in relation to established theoretical frameworks. The cases we describe here show some consistency with the sexual selection hypothesis, but the lack of critical information (i.e., as to paternity) makes it impossible to draw a firm conclusion. This is also the first described case of cannibalism in snub-nosed monkeys.     

Impact of male takeover on intra-unit sexual interactions and subsequent interbirth interval in wild Rhinopithecus roxellana

Data were collected on sexual interactions before and after a male takeover of a one-male unit (OMU) of Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Qinling Mountains, China. The original unit consisted of an adult male, 2 adult and 2 subadult females, 2 female juveniles and a single infant. Following the takeover, the new resident male copulated with 1 adult female, which was not lactating. Subsequent to the disappearance of her infant, the second (lactating female) entered breeding condition and began to solicit copulation with the new resident male. The subadult females also engaged in matings with the new male. The new resident male was observed mating, on 3 occasions, with females in 2 other OMUs. These are the first observations of sexual behaviour in free-ranging Sichuan snub-nosed monkeys after an OMU takeover. Sexual interactions play an important role in establishing relationships between the new male and resident females in the OMU.     

Affiliation Between Aggressors and Third Parties Following Conflicts in Long-Tailed Macaques (Macaca fascicularis)

Studies on cercopithecine monkeys have shown that soon after an agonistic conflict, victims have increased rates of affiliation with the agressor—reconciliation—but not with other group members. Postconflict affiliation is thought to function to restore disturbed relationships and to reduce social tension. This study on a captive group of long-tailed macaques (Macaca fascicularis) is focused on postconflict affiliative behavior of the aggressor. Increased rates of contact between female aggressors and kin of the victim occurred, as well as between female aggressors and their own kin. Furthermore, there were increased rates of contact between aggressors—males and females—and other group members. The increase in contacts with the victim's kin was selective, i.e., it could not be ascribed to the increased contact tendency with group members in general, and was not a side effect of the aggressor's proximity to the victim due to reconciliation. The increase in contacts with own kin was not selective. The fact that male aggressors do not have increased postconflict contacts with their kin or with kin of the victim is in agreement with the notion that males are less integrated in the nepotistic matrilineal network than females are. The fact that studies by others that focused on the victim evidence no increase in postconflict contacts with kin of the opponent or with other group members may be explained by the aggressor's larger influence over the postconflict situation: to reduce social tension, it might be more effective to affiliate with the aggressor than with the victim. Our findings emphasize that conflicts influence the behavior of other monkeys besides the direct contestants and, thus, indicate that the disturbance of social homeostasis is a matter of concern for all group members.     

Postconflict Affiliation of Aggressors in <Emphasis Type="Italic">Papio hamadryas</Emphasis>

Researchers have associated variation in the occurrence of postconflict behaviors with variation in the relationship quality between involved individuals. Apart from those on the great apes, the vast majority of postconflict studies involved female-bonded species and focused on the victim. We examined postconflict affiliation involving the aggressor in a non-female-bonded species, hamadryas baboons (Papio hamadryas), and investigated the influence of relationship quality on the occurrence of 2 types of postconflict affiliative behaviors. Hamadryas baboons reconciled after a conflict and the highest rate of reconciliation was between one-male unit (OMU) leader males and their females. Via direct measures of relationship characteristics we also found that partners with higher-quality relationship, e.g., highly affiliative dyads and allies, showed higher levels of conciliatory tendency than dyads with lower-quality relationship, e.g., less affiliative dyads and non-allies. We found evidence of postconflict third-party affiliation initiated by aggressors, but not by third parties. Further, aggressor-initiated affiliation was more likely with individuals of the same OMU and individuals with which the aggressor maintained a strongly affiliative relationship. Our findings provide further support for relationship quality as a fundamental underlying factor not only in reconciliation, but also in postconflict affiliations involving third parties.     

Social Behavior,Reproductive Strategies,and Population Genetic Structure of <Emphasis Type="Italic">Lagothrix poeppigii</Emphasis>

For species of primates in which females emigrate, we would expect males within groups to be related to one another. Kin selection theory suggests that these males should associate preferentially with one another, be more affiliative and cooperative with one another than females are, and compete less overtly with one another over reproductive opportunities than males in female philopatric taxa do. Precisely these patterns of social behavior characterize well-studied populations of 2 of the 3 atelin primate genera: spider monkeys (Ateles) and muriquis (Brachyteles). For the third atelin genus, Lagothrix, patterns of intragroup social behavior have been less well-documented. We studied the social and reproductive behavior of lowland woolly monkeys (Lagothrix lagotricha poeppigii) in Ecuador during a one-year observational study and subsequently used molecular techniques to investigate population genetic structure and dispersal patterns for this taxon. Among adult male woolly monkeys, both affiliative and agonistic interactions were rare, and males were seldom in close proximity to one another. Relationships among male woolly monkeys are best characterized as tolerant, especially in the context of mating wherein direct competition among males was minimal despite the fact that females mated with multiple males. Relationships among females were likewise generally tolerant but nonaffiliative, though females often directed harassment towards copulating pairs. Affiliative interactions that did occur among woolly monkeys tended to be directed either between the sexes—primarily from female to male—or from younger towards older males, and the proximity partners of females tended to be members of the opposite sex. These results suggest that bonds between the sexes may be more important than same-sex social relationships and that direct female-female competition is an important feature of woolly monkey reproductive biology. Our genetic results indicate that, as in other atelins, dispersal by females is common, but some male dispersal likely occurs as well. In some but not all groups we studied, nonjuvenile males within social groups were more closely related to one another on average than females were, which is consistent with greater male than female philopatry. However, differences in these patterns among our study groups may reflect local variation in dispersal behavior.     

Reconciliation in three groups of lion-tailed macaques

We studied postconflict behavior in three captive groups of lion-tailed macaques (Macaca silenus). After a conflict, we monitored the aggressee as the focal individual during a 10-min postconflict period and made control observations the following day on the same individual. Selective attraction between former opponents occurred in the first minutes of the postconflict period. The conciliatory tendency was relatively high, about 40%. Although no specific behavior was used to reconcile, postconflict contacts were especially intense and a rich repertoire of affiliative patterns was exihibited. With regard to the rate and form of reconciliation, lion-tailed macaques resemble Sulawesi macaques, which belong to the same phyletic lineage. We also discuss the possible interrelations between conciliatory patterns and other characteristics of social organization.     

Market powers predict reciprocal grooming in golden snub-nosed monkeys (Rhinopithecus roxellana)

Social grooming is a common form of affiliative behavior in primates. Biological market theory suggests that grooming can be traded either for grooming or other social commodities and services. When no other services are exchanged, grooming is predicted to be approximately reciprocated within a dyad. In contrast, the amount of reciprocal grooming should decrease as other offered services increase. We studied grooming patterns between polygamous male and female in golden snub-nosed monkeys (Rhinopithecus roxellana) from the Qinling Mountains of central China and found that about 29.7% of grooming bouts were reciprocated. However, the durations of grooming bouts offered and returned was asymmetrical within dyads. In bisexual dyads, more grooming was initiated by females than males, which became more pronounced as the number of females per one-male unit increased. The rate of copulation per day for each female was positively correlated with the total duration of grooming time females invested in males.. Females without an infant (non-mothers) directed more grooming towards females with an infant (mothers) and were significantly more likely to be non-reciprocated. There was a significant negative relationship between non-mother and mother grooming duration and the rate of infants per female in each one-male unit. High-ranking females also received more grooming from low-ranking females than vice versa. The rate of food-related aggressive interactions was per day for low-ranking females was negatively correlated with the duration of grooming that low-ranking females gave to high-ranking females. Our results showed that grooming reciprocation in R. roxellana was discrepancy. This investment-reciprocity rate could be explained by the exchange of other social services in lieu of grooming.     

Female social dynamics in a provisioned free-ranging band of the Sichuan snub-nosed monkey (Rhinopithecus roxellana) in the Qinling Mountains, China

Little information is available on the social dynamics of the Sichuan snub-nosed monkeys (Rhinopithecus roxellana). Here, we provide 5-year observational data on a provisioned free-ranging band in the Qinling Mountains, central China, from October 2001 to December 2005. The results of this study suggested that females place a high priority on maintaining long-term relationships with other female in their one-male units (OMUs). Females had more social interactions with unit members than with nonunit individuals. They showed relatively high rates of affiliation with their unit females, intermediate levels with the resident males, and low levels with individuals outside the unit. Females had few interactions with other resident males. Social interactions, especially affiliative interactions, were more symmetrical between focal females and their unit females than between focal females and the resident males. Thus female social interactions appeared to resemble those of other female-bonded primate societies. On the other hand, female transfers occurred sometimes. We recorded 11 cases of female immigration and 5 cases of female disappearance, 1 case of female intraband shift, and 2 cases of "merging of OMUs," which suggested that unit females might be loose-knit in this species. We discussed influencing factors on female Sichuan snub-nosed monkey social dynamics, by comparing them with those of Hamadryas and gelada baboons that also have multilevel societies.