Male–Male Relationships in Lion-tailed Macaques (<Emphasis Type="Italic">Macaca silenus</Emphasis>) and Bonnet Macaques (<Emphasis Type="Italic">Macaca radiata</Emphasis>)

Socioecology suggests that female distribution in space is determined by the distribution of food resources and the male distribution is influenced by female distribution. Though studies have traditionally focused on females, males have received increasing attention in recent years. We compared male–male relationships in lion-tailed macaques and bonnet macaques. Because bonnet macaques have a high adult male:female sex ratio and are seasonal breeders whereas lion-tailed macaques have a low adult male:female sex ratio and are largely aseasonal breeders, we predicted that bonnet macaque males would be spatially and socially more tolerant of each other and would have less linear dominance relationships than lion-tailed macaques. We recorded male–male and male–female relationships in 1 group of wild macaques of each species via scan sampling and 1–0 sampling. The results revealed that lion-tailed macaque males largely remained at a distance from each other whereas bonnet macaque males remained in close proximity to one another. Lion-tailed macaque males were more agonistic toward each other whereas bonnet macaque males showed more affiliative interactions. The dominance hierarchy among lion-tailed macaque males was more linear than among bonnet macaque males. Our data support the hypothesis that the study of spatial structuring, temporality of interactions, and linearity of social relationships may contribute to a better understanding of macaque social systems.     

Blood groups of bonnet macaques (Macaca radiata), with a brief introduction to seroprimatology

The human-type A-B-O blood groups of 52 bonnet macaques (Macaca radiata) were determined. Application of method of population genetics indicated the gene frequences to be O = 0.173, A = 0.480 and B = 0.347. Cross testing of sera and red cells of the bonnet macaques revealed two blood-type-specific isoagglutinins, one of them strong enough for use as a blood typing reagent. No blood group polymorphism was revealed by testing bonnet macaque red cells with isoantisera produced in rhesus monkeys (M. mulatta) and in crab-eating macaques (M. fascicularis). The rhesus and crab-eating macaque isoantisera reacted either with all or with none of the bonnet macaque red cells tested.     

Allogrooming in two species of macaque (Macaca nemestrina andMacaca radiata)

This paper analyzes allogrooming (social grooming) data collected from two large, fully integrated and long established social groups of macaques (one of pigtail macaques and one of bonnet macaques). The data demonstrates a species and sex difference for total allogrooming given with females of both species giving more grooming than the males and with pigtails as a species giving more grooming than bonnets. Also, pigtail females gave more allogrooming to clan members than to nonclan members, but this was not true for pigtail males, bonnet males, and bonnet females. Allogrooming given and allogrooming received by age class for both species showed development of a sexual dichotomy at three to four years. The analysis characterized some of the social structures extant in two closely related species of macaque, particularly the somewhat different use of allogrooming in pigtail females as opposed to the other three categories of animals. Social implications with relation to macaque societies are discussed.     

Social Relationships in Free-Ranging Male Macaca arctoides

Macaque social relationships differ greatly between species. Based on captive studies that focus mainly on females, researchers have classified stumptail macaque (Macaca arctoides) social relationships as tolerant, as indicated by a high rate of affiliation, frequent aggression, and symmetrical conflicts. To accumulate more data on male social relationships, which are relatively understudied, and to generate comparative data, we investigated male social relationships in a provisioned group of 68 free-ranging, naturally dispersing stumptail macaques in southern Thailand. We collected continuous focal animal and ad libitum data on 7 adult and 2 subadult males, recording social behavior during 283 contact hours between December 2006 and March 2007. Stumptail macaques of this population were less tolerant than predicted based on previous studies on captive groups: Rates of spatial proximity, affiliation, and aggression were low, most males directed affiliative behavior toward higher-ranking males, and conflicts were generally of low intensity and relatively asymmetrical. Thus, male stumptail macaques of the focal group appear to differ in their social style from a previous study of a captive group that mainly comprised of females. In some traits, they are even more intolerant than rhesus macaques, an intensively studied intolerant macaque species. We also compare our data on stumptail macaque males to those on other male macaques, but available data are too sparse to draw final conclusions.     

Symmetrical patterns in non-agonistic social interactions found in unprovisioned Japanese macaques

Non-agonistic social interactions in an unprovisioned troop of Japanese macaques (Macaca fuscata yakui) were analyzed with the spacing between individuals, leading-following interactions, and exchange of social grooming. The most frequent interactions were found between kin-related females. Unrelated females stayed with one another rather frequently, but rarely exchanged social behaviors. Interactions between males and females were infrequent though they were occasionaly observed between high-ranking males and high-ranking females. Very frequent exchange of grooming was observed between males, and even high-ranking males exchanged grooming more frequently with males than with females. Most non-agonistic social interactions in the study troop were based on bidirectional exchange of social behaviors, in which no clear tendency relevant to dominance or sex was found; while in provisioned Japanese macaque troops, associations between males and females, between unrelated females, and between males were formed mainly be subordinates' active roles in associative behaviors. This seems relevant to the idea that dominance grealty influence social life in provisioned troops. The present study provides guidelines for interspecific comparison of social interaction patterns of macaque species.     

Evaluating Dominance Styles in Assamese and Rhesus Macaques

Researchers have suggested that several types of agonistic and affiliative behavior covary as a set of species-specific traits, and have used the term dominance style to describe the covariation. We compared measures of dominance style between a group of Assamese macaques (Macaca assamensis) and a group of rhesus macaques (M. mulatta), though kinship information was unknown. Assamese and rhesus female-female dyads each showed a low proportion of counter aggression and a low conciliatory tendency, suggesting that they have despotic social relationships. They also showed a despotic pattern on several other types of agonistic and affiliative behavior, such as approach outcomes and grooming distributions, which is consistent with the covariation of dominance style traits. Assamese male-male dyads showed relatively high levels of reconciliation and counter aggression versus other macaque males portrayed in the literature, suggesting that Assamese males have a tolerant dominance style. Insofar as macaque dominance style depends on the behavior of females, we suggest that Assamese macaques, like rhesus macaques, have despotic social relationships, which contrasts with evidence of a strong correlation between phylogeny and dominance style in macaques. Further, our results indicate that strong male bonding and tolerant dominance relationships among males are independent of female dominance style. Lastly, some measures of agonistic behavior, such as rate of aggression or proportion of bites, are likely altered in competitive environments and thus are not useful indicators of dominance style.     

Of Least Concern? Range Extension by Rhesus Macaques (<Emphasis Type="BoldItalic">Macaca mulatta</Emphasis>) Threatens Long-Term Survival of Bonnet Macaques (<Emphasis Type="BoldItalic">M. radiata</Emphasis>) in Peninsular India

Rhesus and bonnet macaques are the 2 most common and widely distributed of the 8 macaque species of India. Rhesus macaques are widely distributed across southern and southeastern Asia, whereas bonnet macaques are restricted to peninsular India. We studied the current distributional limits of the 2 species, examined patterns of their coexistence in the interspecific border zones, and evaluated losses in the distributional range of bonnet macaques over the last 3 decades. Our results indicate that whereas rhesus macaques have extended their geographical range into the southern peninsula, bonnet macaques have been displaced from many areas within their former distributional range. The southern and the northern distributional limits for rhesus and bonnet macaques, respectively, currently run parallel to each other in the western part of the country, are separated by a large gap in central India, and converge on the eastern coast of the peninsula to form a distribution overlap zone. This overlap region is characterized by the presence of mixed-species troops, with pure troops of both species sometimes occurring even in close proximity to one another. The range extension of rhesus macaque—a natural process in some areas and a direct consequence of introduction by humans in other regions—poses grave implications for the endemic and declining populations of bonnet macaques in southern India.     

Affiliative relationships and reciprocity among adult male bonnet macaques (Macaca radiata) at Arunachala Hill, India

In captivity, male bonnet macaques (Macaca radiata) frequently express "friendship" toward one another, including affiliative behavior such as huddling, grooming, coalitionary support, and sitting in close proximity. The purpose of this study was to determine whether wild adult male bonnet macaques also express "friendship" by investigating whether or not (1) adult male bonnet macaques have affiliative social relationships with other males, (2) the strength of social relationships varies among dyads, (3) there is time-matched reciprocity in allogrooming among dyads, and if so, whether the level of reciprocity occurs within a bout of grooming, a day, or over 2 months (the limit of this study), and (4) a correlation exists between the strength of social relationships and dominance ranks among adult males. Focal samples totaling 150 hr on all seven adult males in one study group were conducted to record both agonistic and affiliative interactions. Agonistic interactions were used to construct a dominance hierarchy, whereas affiliative interactions (sitting in proximity to within 1 m with and without grooming) were used to quantify the existence and strength of social bonds within dyads. Results show that adult male bonnet macaques had differentiated affiliative relationships with other males in their group. There was little reciprocity of grooming within a bout of grooming or within a day, but greater reciprocity over the study period of 2 months. There was no correlation between dominance ranking distance and the strength of affiliative relationship within dyads; however, within dyads lower-ranking males groomed higher-ranking males more than vice versa. This study suggests that friendships in male bonnet macaques are characterized not by immediate tit-for-tat reciprocal altruism, but by reciprocity over a longer time span, and that affiliative social relationships may be less constrained by agonistic relationships than is the case in more despotic species of macaques.     

The Influence of Age,Sex, and Rank on Yawning Behavior in Two Species of Macaques (Macaca fascicularis and M. fuscata)

Yawning behavior was studied in two species of macaques: the long-tailed macaque (Macaca fascicularis) and the Japanese macaque (M. fuscata). Japanese macaques yawned much more than long-tailed macaques. Age, sex, and dominance rank exerted different effects on yawning in the two species. In the long-tailed macaques, sex differences in frequency of yawning emerged only after sexual maturity; yawning rates increased significantly in both males and females as they reached sexual maturity; and, among males, dominance rank was positively correlated with frequency of yawning. Differently, in the Japanese macaques, males, both mature and immature, yawned more than same-aged females; sexual maturity was associated with an increase in yawning in males only; and male rank did not correlate with the frequency of yawning. Regardless of interspecific differences, the overall results supported only in part the finding that, in Old World monkeys, yawning is largely influenced by plasma concentrations of androgens. There was evidence that social factors were also important in influencing the age-sex class distribution of yawning.     

Population genetical study of Japanese macaques,Macaca fuscata,in the shimokita A1 troop,with special reference to genetic variability and relationships to Japanese macaques in other troops

The genetic variations of 35 individuals of the Shimokita A1 troop of mainland Japanese macaques,Macaca fuscata fuscata, which live at the northern end of the habitat of the species, were investigated using 33 electrophoretically detectable blood protein loci. Among the loci examined, six were polymorphic. The average heterozygosity per individual was calculated as 0.0442. This was the highest value among all troops of Japanese macaques so far investigated. The mainland macaques of the Shimokita A1 troop were more differentiated genetically from other mainland macaque troops than were Yaku macaques, the subspeciesM. f. yakui.     

Inter-male associations in a wild Japanese macaque troop on Yakushima Island,Japan

Adult male association and its annual change were studied in a wild population of Japanese macaques (Macaca fuscata yakui) on Yakushima Island, Japan. Unlike many other Japanese macaque troops, adult troop males frequently maintained proximity and exchanged grooming with one another in both the mating and non-mating seasons, and the dominance relationship rarely appeared in such inter-male associations. The few cases of agonistic interactions occurred mostly when estrous females or food resources were immediately concerned. Although troop males were very intolerant to newly appeared solitary males (new males) during the mating season, close associations were formed between troop males and new males as soon as the mating season terminated. The consort of new males and lower-ranking troop males with estrous females was frequently disturbed, but these males could copulate no less frequently than higher-ranking males. A comparison among macaque species suggests the existence of two forms of inter-male association: (1) the frequent association based on the symmetrical exchange of social behaviors; and (2) the infrequent and asymmetrical association related to the dominance relationship. The form of inter-male association seems to be influenced by whether or not males can keep close associations with females throughout the year.     

Male life history in natural populations of Japanese macaques: Migration, dominance rank, and troop participation of males in two habitats

This paper compares male life history parameters of two populations of Japanese macaques (Macaca fuscata Blyth, 1875), studied without provisioning: Yakushima (M. f. yakui), a subtropical forest habitat in southwestern Japan, and Kinkazan (M. f. fuscata), a temperate, deciduous forest habitat in northeastern Japan. The males of the two sites experienced similar life histories with respect to several traits. Age at natal dispersal was at about 5 years. Average troop residence was about three years. Most males joined troops at the bottom of the rank order, although a few males joined troops at the top rank. Dominance ranks of males tended to rise with the death or departure of higher ranking males. Visiting males accounted for about 41% of observed mating at both sites. However, the two sites differed in the sex ratio of troops, partly because a larger proportion of males apparently lived outside of troops in the Kinkazan site compared to Yakushima. In particular, non-natal young males were absent from the main study troop at Kinkazan. Large within-species variation may exist in the degree to which males associate with troops.     

Threat-Related Acoustical Differences in Alarm Calls by Wild Bonnet Macaques (Macaca radiata) Elicited by Python and Leopard Models

Wild and urban bonnet macaques (Macaca radiata) were studied in southern India to record alarm calls during presentations of realistic models of spotted and dark leopards (Panthera pardus) and an Indian python (Python molurus). Recordings of alarm calls were made from members of four forest troops at feeding stations who observed brief and prolonged presentations of fully exposed spotted and dark leopard morphs and partially concealed views of the spotted morph. Four different forest troops were presented a slowly moving python near feeding stations. Two predator‐inexperienced urban troops from the city of Bangalore were presented either the spotted leopard morph briefly or the python. Analyses of alarm calls revealed differences in acoustic structure, such as a lower harmonic to noise ratio, which can be interpreted as reflecting the level of perceived threat rather than predator type. Noisy alarm calls likely indicate high states of physiological arousal that might provide eavesdropping troop members with information useful for assessing the urgency of the predatory threat. Lack of alarm‐call distinctiveness characterizing predator type is complemented by explicit contextual information in which alarm calling to leopards never occurred on the ground whereas nearly all initial python‐elicited alarm calls were made by individuals on the ground monitoring the python. The alarm calls of Bangalore monkeys distinguished the leopard and python models, with the latter engendering the noisiest calls and immediate flight to trees. Such flight is unnecessary with the python and suggests that, without appropriate experience with pythons, bonnet macaques adopt less predator specific refuge‐seeking behavior.     

A case of simple tool use in wild liontailed macaques (Macaca silenus)

Three members of a group of liontailed macaques (Macaca silenus) were seen to use leaves for food preparation. Other examples of prey-selection and hunting behaviour in liontailed macaques reflect individual- and group-specific skills. The absence of similar patterns in bonnet macaques (Macaca radiata) living in the same habitat might be related to differences in the social design and indicate the high significance of social aspects for the occurrence and manifestation of innovative behaviour.     

The social position of male Barbary macaques (Macaca sylvanus) in a semifree-ranging population

A study was carried out on the social position of 12 subadult males of a semifreeranging Barbary macaque population during the non-mating season. The social position was measured in terms of spatial as well as interactive parameters. The subadult males had social contacts to members of nearly all other age-sex classes but showed clear preferences for same-sexed partners. Besides this differences were found between 5- and 6-year-old males with respect to their interaction profiles and the preference for special classes of interaction partners. The terms “peripheral-central” is discussed with reference to the social structures of macaque societies. The data of the present study indicate that the social position of subadult male Barbary macaques can not be described by one of these terms exclusively. The results are compared to other studies on Barbary macaques and other macaque species. It is concluded that in macaque societies subadult males are not obligatorily forced to live at the periphery or to abide. It is proposed not to postulate stiff social structures but to put more emphasis on the range of variation among macaque species.     

Preliminary report on yellow long-tailed macaques (Macaca fascicularis) at Kosumpee Forest Park, Thailand

We conducted a census on long-tailed macaques (Macaca fascicularis) at Kosumpee Forest Park, Thailand, and found 15 individuals of yellow pelage color out of a total of 287 individuals. There were three troops, designated A, B and C, but the yellow macaques were found only in B and C troops. The frequency of yellow macaques was 5.2% in the total population and 4.2 and 9.9% in B and C troops, respectively. These frequencies are much higher than those in rhesus macaques (M. mulatta) reared at Cayo Santiago (0.52%). They are, however, lower than those of 10 years ago.     

Application of paternity discrimination by DNA polymorphism to the analysis of the social behavior of primates

Paternity in many primate species cannot be established reliably on behavioral grounds. For instance, Japanese macaques (Macaca fuscata) have a multi-male group structure and promiscuous mating patterns. On the other hand, accurate evaluation of male reproductive success is needed to analyze primate behavior. DNA finger-printing techniques were applied to 2 captive groups of Japanese macaques in the Primate Research Institute of Kyoto University for identification of paternity. Also, mating behavior of a captive group was observed in order to compare the reproductive success of each male with that expected on the basis of his observed mating activity. The number of offspring of full adult males was not related to their social rank although the number of copulations with ejaculation was highly correlated with their social rank. Monitoring of the female sexual cycles from the plasma profiles of gonadotropins and ovarian hormones suggested that males could not choose females at days of ovulation. The results of two-free-ranging wild troops, like those of the captive groups, indicated that high-ranking males could not monopolize the paternity of offspring. The results of paternity discrimination in Japanese macaques were compared with results from patas monkeys (Erythrocebus patas) in a discussion of social structure and male reproductive success. Some aspects of polymorphism detection techniques are also discussed.     

Social Behavior of Captive Indochinese and Insular Long-Tailed Macaques (Macaca fascicularis) Following Transfer to a New Facility

There are measurable differences in behavior, physiology, social organization, and geographic distribution within and between various species of macaques. We collected information on the social behavior of captive Macaca fascicularis from Indochina and island populations after they had been transferred to a new environment and new social groups. While some changes in behavior occurred over time, we found no decrease in high levels of agonistic behaviors. We interpret this finding in light of previous research reporting that long-tailed macaques show low levels of habitatuation to novelty and are highly aroused in comparison to other macaque species. We found predictable differences in behavior for males, females, and infants, in which infants played more, females had higher levels of contact proximity to other individuals, and males exhibited more sexual and threat behavior. A comparison of social behavior in long-tailed macaques from different origins indicate that Indochinese macaques are generally less affiliative and Indochinese males are more aggressive than their insular counterparts. Differences among macaque species, and within the fascicularis-group, should be considered in management of captive colonies and when interpreting research data.     

Early environment shapes the development of gaze aversion by wild bonnet macaques (<Emphasis Type="Italic">Macaca radiata</Emphasis>)

Among many species of primates, staring is perceived as a sign of aggression and averting the gaze usually serves to reduce such conflict. The current study conducted in southern India documented developmental differences among wild bonnet macaques (Macaca radiata) in their latency to gaze avert after establishing eye contact with other individuals. Feeding stations were used to gather macaques within a small area to facilitate the video recording of group dynamics and eye contact between subordinate and dominant individuals. Individuals were grouped into three age classes: juveniles, subadult males, and adult males. Comparisons were also made between urban and forest dwelling troops. In the forest, juveniles established eye contact with older males for significantly longer periods of time than did adults. A linear trend was observed in which the latency to gaze avert after establishing eye contact decreased with age. This trend was not evident in the urban troops, for which the latency to gaze avert did not change significantly with age. Urban juveniles were also more likely to be chased when they established eye contact with adults compared with their forest counterparts. These differences could be the result of increased predatory risk in the forest setting — the necessity for heightened predator vigilance in forests may reduce the frequency with which juveniles are monitored and chased or attacked as a result of their eye contact. Conversely, the rarity of predators in the city may engender more intense aggressive behavior between monkeys, accelerating the rate of learning to signal appeasement to dominant males.     

Organization of Group Members at Departure Is Driven by Social Structure in Macaca

Researchers have often explained order of progression of group members during joint movement in terms of the influence of ecological pressures but rarely that of social constraints. We studied the order of joining by group members to a movement in semifree-ranging macaques with contrasting social systems: 1 group of Tonkean macaques (Macaca tonkeana) and 1 group of rhesus macaques (M. mulatta). We used network metrics to understand roles and associations among individuals. The way the macaques joined a movement reflected the social differences between the species in terms of dominance and kinship. Old and dominant male rhesus macaques were more often at the front of the movement, contrary to the Tonkean macaques, which exhibited no specific order. Moreover, rhesus macaques preferred to join high-ranking or related individuals, whereas Tonkean macaques based associations during joining mostly on sexual relationships with a subgroup of peripheral males.