Male and female agonistic and affiliative relationships in a social group of farm cats (Felis catus L.)

A dominance hierarchy based on the outcome of agonistic encounters was found among male and female domestic cats. A female dominated over some males. The dominance concept is also discussed in terms of social bonding. The relationships among adult females were amicable, whereas adult males showed reciprocal tolerance. The flow of affiliative behaviour was directed mainly from females to one male of the group. The analysis of marking behaviour showed that this male sprayed urine and rubbed the perioral and cheek regions of the face on the objects of the environment at a higher rate than the other members of the group. Nevertheless, rubbing the perioral and cheek regions of the face on objects was not correlated to dominance rank, possibly because it has some function in social communication other than territorial defence against strangers. No relationships have been found between claw scratching, rolling on the ground and social rank, or between the former and other marking behaviour. It is concluded that claw scratching and rolling were not utilised to mark territory.     

Social behaviour and heart rate in tammar wallabies (Macropodidae: Macropus eugenii)

In an enclosed group of tammar wallabies the behaviour of all individuals and the heart rate (HR) of three males were recorded simultaneously. The social structure was characterized by the dominance relationships between the males and the sexual preference of all males for the oldest female. During non-oestrus, dominance was obvious when a male intervened terminating the sexual behaviour of a subdominant one. The relatively low amount of agonistic behaviour between the males is assumed to be due to the clear dominance relationships. Locomotion as well as sexual and agonistic behaviour were accompanied by an acceleration of HR. The HR pattern depended on the intensity of the behaviour, its duration and the animal's identity. Commonly performed sexual behaviour and approach/retreat encounters gave rise to HR values not different from HR values during locomotor activity without interactive components. Social events that occurred infrequently—like fights, and the mating of an oestrous female—were accompanied by strong accelerations of HR indicating high cardiac effort. The mild cardiac activity during common social encounters is consistent with a strategy of maximizing energy conservation. HR patterns during specific behaviour could not entirely be accounted for by the energetic costs of activity. Spreading the forelimbs in response to specific stimuli—like the fly-over of raptors—was indicative of a strong HR response even if the animal was motionless. During specific social encounters like the sexual behaviour of the alpha-male following an intervention—HR responses revealed that arousal might exceed motor activity in affecting HR. Individual differences of these HR responses are attributed to the age, experience and social status of a male.     

Hierarchical structure and the influence of individual attributes in the captive squirrel monkey (<Emphasis Type="Italic">Saimiri collinsi</Emphasis>)

The dominance structure of primate social groups varies widely. In addition to the groups’ composition, intrinsic attributes such as sex, body size and life experience are important factors that can affect hierarchical dominance relations. All primates are social animals, and the social environment has a direct influence on the physiological conditions of vital systems such as immunological, reproductive and cardiovascular systems. In this study, we analyze the hierarchical structure of Saimiri collinsi in captivity, including the hierarchical structure type, the influence of individual intrinsic characteristics (sex, age, weight and origin—born in captivity or in the wild) based on the prior-attributes model, the relation between agonistic behavior frequency and hierarchical position, and hierarchy steepness, which represents the dominance gradient. We found that the group order was characterized by a partial hierarchy: a dominance position could be occupied by more than one individual simultaneously, including individuals of both sexes. Intrinsic characteristics had no influence on hierarchical structure, with the exception of the male in the highest hierarchical position, which had a markedly larger body than all other group members. Thus, the prior-attributes model did not apply to hierarchical formation of S. collinsi in captivity. Only the frequency of agonistic behavior of males correlated with their hierarchical position, and they differed from all other group members in their more aggressive behavior. The steepness between adjacent positions along the dominance gradient was significant only between the dominant male and the next individual in the group, with a smooth gradient between the other positions in the rank. As the access to resources is directly related to hierarchical dominance, a smooth dominance gradient is to be expected in species that form very large groups, such as wild Saimiri populations.     

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.     

Differences in Behavior and Social Organization of Female Guinea Pigs as a Function of the Presence of a Male

Object of the study was the variability of social behavior and organization in female guinea pigs as a function of the presence of a male. Four groups of 8 females were observed. Two of these groups were without a male, the other two had a sexually experienced, sterilized male. All females were about 20 d old at the beginning of the study. In the groups without a male the females formed clear and stable dominance relationships resulting in a linear rank order. The frequency of agonistic behavior was higher compared to the other groups. Some of these females displayed male-like courtship behavior. Among the females in the groups with a male only the alpha and omega positions were stable, while the dominance relations between the other females remained unstable. These females directed about 40–50 % of their contact behavior towards the male. In relation to the presence or absence of a male the females differed in their social orientation: those who lived with a male were strongly orientated towards it, those living without a male were strongly oriented towards each other. The hypothesis is put forward, that the females in the two situations differed in their motivational states. For the females living with a male this animal was a stable point of social reference, while for the females living without a male their stable dominance structure — with more agonistic behavior — was the most important stabilizing factor.     

Male-male Interactions in Heterosexual and All-male Wild Mountain Gorilla Groups

Variation in male dispersal and behavior patterns are components of intraspecific differences in social systems. A comparison of male behavior in different social settings can be useful for determining which behavioral mechanisms contribute to variability in social systems. Two heterosexual multimale groups and one all-male group of mountain gorillas (Gorilla gorilla beringei) were observed for over 1100 h at the Karisoke Research Centre, Rwanda. Data on proximity patterns, dominance relationships, aggression, agonistic interventions, affiliation, and homosexual behavior were compared among the males in these groups to examine the influence of female presence, sex ratio, group size, and kinship on male—male interactions. Males in the all-male group stayed closer together, affiliated more, exhibited more homosexual behavior, and were more aggressive toward each other than males in heterosexual groups. However, the males in heterosexual groups showed more wounding and more consistent dominance relationships. Kinship did not influence male-male relationships in the all-male group. The males in the heterosexual groups rarely interacted with one another; they may actively avoid close proximity to reduce aggression. Results suggest that the variable social system of mountain gorillas may be more strongly influenced by demographic factors, male-female social relationships, and male-male competition for mates than by any benefits of male-male relationships.     

Inter-individual relationships in proboscis monkeys: a preliminary comparison with other non-human primates

This is the first report on inter-individual relationships within a one-male group of proboscis monkeys (Nasalis larvatus) based on detailed identification of individuals. From May 2005 to 2006, focal and ad libitum data of agonistic and grooming behaviour were collected in a forest along the Menanggul River, Sabah, Malaysia. During the study period, we collected over 1,968 h of focal data on the adult male and 1,539 h of focal data on the six females. Their social interactions, including agonistic and grooming behaviour, appeared to follow typical patterns reported for other colobines: the incidence of social interaction within groups is low. Of 39 agonistic events, 26 were displacement from sleeping places along the river, 6 were the α male threatening other monkeys to mediate quarrels between females and between females and juveniles, and 7 were displacement from feeding places. Although the agonistic behaviour matrix based on the 33 intra-group agonistic events (excluding events between adults and juveniles and between adults and infants) was indicative of non-significant linearity, there were some specific dominated individuals within the group of proboscis monkeys. Nonetheless, grooming behaviour among adult females within a group were not affected by the dominance hierarchy. This study also conducted initial comparisons of grooming patterns among proboscis monkeys and other primate species. On the basis of comparison of their grooming networks, similar grooming patterns among both-sex-disperse and male-philopatric/female-disperse species were detected. Because adult females in these species migrate to groups repeatedly, it may be difficult to establish the firm grooming exchange relationship for particular individuals within groups, unlike in female-philopatric/male-disperse species. However, grooming distribution patterns within groups among primate species were difficult to explain solely on the basis of their dispersal patterns. Newly immigrated females in some species including proboscis monkeys are eager to have social interactions with senior group members to improve their social position.     

Population size,social behaviour,and dispersal in house mice: A quantitative investigation

An experimental study was conduced to examine some relationships between population size, social behaviour, and dispersal utilizing wild genotype Mus musculus in seminatural enclosures. Groups of male and female mice were used to simulate natural populations. The results indicate that male territoriality occurred significantly more often in populations of greater size but equal density, and these groups demonstrated a significantly greater rate of agonistic interactions per animal when compared to smaller populations. No significant differences were observed for other categories of social interaction. The percentage of animals emigrating and the population density following emigration were the same in small and large groups.     

雄性大仓鼠体重对其斗殴行为及社会等级的作用

在实验室条件下测定雄性大仓鼠体重对社会等级和斗殴行为的作用模式,检验体重对雄性大仓鼠社会等级及斗殴行为序列具有重要影响的假设。本实验以16只成年雄性大仓鼠为目标个体,采用等级内部的线性概率、组内循环三元组数量（d）和优势等级的线性度（K）,排列个体的社会等级序位。研究结果表明,雄性大仓鼠可形成近似线性的优势等级,体重与个体的优势等级,攻击行为和胁腺标记行为均呈显著的正相关关系,与防御行为和攻击潜伏期存在显著的负相关关系。说明独居性物种大仓鼠雄体间可形成优势等级关系,体重对此关系具有重要的作用。     

Aggression and dominance in the weaver bird, Quelea quelea.

Previous work on agonistic behaviour in Quelea has been concerned primarily with hormonal variables. In the present series of experiments, a number of behavioural correlates of aggression and dominance are examined in male and bisexual groups. These include the effects of group arousal level on rates of agonistic encounters, the relationship between an individual's habitual level of activity and its relative dominance, aggressiveness and position on the perch in a resting "flock". The temporal patterning of encounters is analysed and the reasons why encounters tend to clump in time determined. The relationship between dominance in encounters over individual-distance infringements and dominance in encounters over access to a restricted food source is investigated and the effects of this on loss of weight in males and females determined. The results are discussed in relation to Ward's (1965) finging that in the wild females suffer higher mortality than males during the dry season and in relation to the general determinants of aggression in Quelea.     

Hierarchy,kinship and social interaction among Japanese monkeys (Macaca fuscata)

The study reports the relationship between hierarchy, genetic relatedness and social interaction in captive Japanese macaques. Grooming and proximity were found to be positively related to both dominance rank and degrees of relatedness. Ranks also positively correlated with threats while no relationship was observed between genetic relationships and agonistic interactions. The removal of a-male tightened the male hierarchy while the female hierarchy became relatively loose. Affiliative behaviour became more correlated with ranks than degrees of genetic relatedness. In the absence of α-male, the next dominant male avoided involvement in either agonistic or afliliative interactions with reintroduced animals and group females.     

Spoiled Brats: Is Extreme Juvenile Agonism in Ring‐Tailed Coatis (Nasua nasua) Dominance or Tolerated Aggression?

Ring‐tailed coatis exhibit an extreme form of juvenile agonism not found in other social mammals. Two groups of habituated, individually recognized, coatis were studied over a 2.5‐yr period in Iguazu National Park, Argentina. Dominance matrices were divided by year and group, resulting in four dominance hierarchies which were analyzed using the Matman computer program. Strong general patterns were seen in both groups during both years. Adult males (one per group) were the highest ranking individuals, followed by male juveniles, female juveniles, adult females, and male and female subadults. The pattern in which young, physically inferior individuals were able to outrank larger adults is different from other social mammal species in that the juvenile coatis aggressively defended food resources and directed aggression towards older individuals. These agonistic interactions may not reflect ‘dominance’ in the traditional sense, and appear to be a form of ‘tolerated aggression.’ This tolerated aggression leads to increased access to food, and should help juveniles during a period in which they need to rapidly gain weight and grow. Because this tolerance of juvenile aggression is reinforced through coalitionary support of juveniles by adult females, agonistic patterns are also consistent with the hypothesis that juvenile rank is being influenced by high degrees of relatedness within coati groups. Although some interesting parallels exist, there is little evidence indicating that these dominance patterns are the same as those found in other social mammals such as hyenas, lions, meerkats, or Cercopithicine primates.     

Long-term patterns of agonistic interactions in a captive group of wolves (Canis lupus)

Agonistic interactions were recorded in a captive group of wolves (Canis lupus) for a period of 21 months. Seventy-five per cent of all interactions were accounted for by only 4 or less of a possible 28 pairs during any given period of the study. Several animals were involved in very few agonistic interactions, and in many relationships such interactions were absent. Patterns of agonistic interaction alone did not suggest social relationships or an overall social structure applicable to all group members, although some evidence of a dominance hierarchy was found. Patterns of agonistic interactions were shown to involve several independent dimensions in different relationships. Further details of an underlying social organization are likely to emerge only from long-term studies which examine several dimensions of, and the interrelations between, a wide range of social interactions.     

Pattern of Social Interactions after Group Integration: A Possibility to Keep Stallions in Group

Horses are often kept in individual stables, rather than in outdoor groups, despite such housing system fulfilling many of their welfare needs, such as the access to social partners. Keeping domestic stallions in outdoor groups would mimic bachelor bands that are found in the wild. Unfortunately, the high level of aggression that unfamiliar stallions display when they first encounter each other discourages owners from keeping them in groups. However, this level of aggression is likely to be particularly important only during group integration, when the dominance hierarchy is being established, whereas relatively low aggression rates have been observed among stable feral bachelor bands. We investigated the possibility of housing breeding stallions owned by the Swiss National Stud in groups on a large pasture (5 stallions in 2009 and 8 stallions in 2010). We studied the pattern of agonistic, ritual and affiliative interactions after group integration (17–23 days), and the factors influencing these interactions (time after group integration, dominance rank, age or experience of group housing). We found that stallions displayed generally more ritual than agonistic and than affiliative interactions. The frequency of agonistic and ritual interactions decreased quickly within the first three to four days. The frequency of affiliative interactions increased slowly with time before decreasing after 9–14 days. A stable hierarchy could be measured after 2–3 months. The highest-ranking males had less ritual interactions than the lowest-ranking. Males had also less agonistic, ritual and affiliative interactions if they had already been housed in a group the previous year. Therefore, we found that breeding stallions could be housed together on a large pasture, because the frequency of agonistic interactions decreased quickly and remained at a minimal level from the fourth day following group integration. This housing system could potentially increase horse welfare and reduce labour associated with horse management.     

Special relationships instead of female dominance for redfronted lemurs,Eulemur fulvus rufus

Most lemurs yet studied in detail exhibit some mode of adult female social dominance over males. The known exception, a brown lemur subspecies known as rufous or redfronted lemurs (Eulemur fulvus rufus), forms multimale–multifemale social groups within which unambiguous dominance relations are not observed among adults. Resting groups of redfronted lemurs consistently include huddling adult male–female pairs whose males selectively scentmark and rub their heads in the scentmarks of their female huddling partners. Quantitative observations confirmed that some of these male–female pairs maintain special relationships satisfying all criteria originally developed in research on cercopithecine monkeys. Observations before, during, and after mating season, intergroup encounters, male transfers, and changes in male–female affiliations illuminated developmental and functional aspects of male–female partnerships. Each adult female in two semi-free-ranging study groups shared high rates of association, grooming, and agonistic support and low rates of agonistic interaction with one unrelated or distantly related adult male partner. Such affinity characterized small proportions of adult male–female relationships. Several males directed not only support but also aggression toward adult females with whom they sought to affiliate. All bonded males sought to copulate with their partners, and some appeared to ignore estrus in nonpartners. All females accepted copulation attempts from partners and some seemed to prefer their partners as mates. Partial synchronization of brief estrus periods together with concealed ovulation appeared to minimize chances for polygynous mating. Results support the view that the male–female pair is the fundamental social unit of E. fulvus and suggest that female partnership with individual males obviates dominance behavior, including female dominance, in this lemurid primate. Am. J. Primatol. 43:239–258, 1997. © 1997 Wiley-Liss, Inc.     

Predictors of social dominance in the adult female golden hamster (Mesocricetus auratus)

Adult female golden hamsters exhibit smaller and less pigmented flank glands than do males. Nevertheless, as has been found in male hamsters, variations in these parameters of the flank glands correlate highly (r_s=0·78) with social rank attained in a group of four females. Ovariectomy and subsequent replacement with a graded series of testosterone propionate doses produces a directly related response in the flank gland and in the social rank attained in all-female groups (r_s=0·72). Body weight of females also correlates directly with social status (r_s=0·74), but, when body weight is held constant, social rank can still be predicted from measures of the flank gland. Oestrous-related fluctuations in aggressive behaviour of females did not alter dominance relationships.     

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.     

Female social dominance in two Eulemur species with different social organizations

Female social dominance is rare in mammals, but common in lemurs. We investigated social dominance in two Eulemur species; the polygynous crowned lemur (E. coronatus) and the monogamous red‐bellied lemur (E. rubriventer), using four and two social groups, respectively. We collected data on agonistic interactions and two types of affiliative behavior (grooming and maintaining spatial proximity). We used a combination of focal watches of individuals, instantaneous scan‐sampling of groups, and all‐occurrence of some behaviors in groups. We found that overall rates of agonistic interactions were higher in E. coronatus, and they also had more decided intersexual agonistic interactions than E. rubriventer. However, in both species the females won the vast majority of these agonistic interactions. E. coronatus females were groomed more often by males than vice versa, whereas no sex differences in grooming were observed in E. rubriventer. We found that males were responsible for maintaining spatial proximity in E. coronatus whereas in E. rubriventer, females were responsible. In one group of E. coronatus, the male was overweight and dominant to the female and this is the first observation of male dominance in a lemur species typically described as female dominant. We suggest that body weights in captivity be monitored for maintaining normal dominance relationships. Overall, agonistic behaviors were consistent with clear female social dominance in both E. coronatus and E. rubriventer. The affiliative behaviors also provided clear evidence for female dominance E. coronatus, but not for E. rubriventer. Zoo Biol 0: 1–14, 2007. © 2007 Wiley‐Liss, Inc.     

Marking behaviour in two lemur species (L. fulvus and L. macaco): relation to social status, reproduction, aggression and environmental change.

The influence of social status, reproductive and agonistic contexts and environmental change on scent-marking and allomarking rates were studied in captive groups of Lemur fulvus and Lemur macaco. No evidence of female social dominance over males appeared in either species. In L. fulvus, intrasexual relationships were characterized by the dominance of one adult male over another and by the existence of female affiliative association ('central' vs. 'peripheral' females). In L. macaco, no intrasexual dominance relationships were apparent except for a brief ostracism of one female. In both species, (1) intrasexual differences in social status were related to differences in marking rates, (2) no direct relation appeared between marking rates and aggression or reproduction, (3) allomarking was not differentially directed towards specific individuals and (4) physical environmental factors clearly influenced scent-marking and allomarking rates. These results are discussed in relation to the possible functions of marking behaviour in intragroup relations.     

Dominance hierarchy and social relationships in a group of Captive black-and-white snub-nosed monkeys (Rhinopithecus bieti)

Different types of dominance hierarchies reflect different social relationships in primates. In this study, we clarified the hierarchy and social relationships in a one-male unit of captive Rhinopithecus bieti observed between August 1998 and March 1999. Mean frequency of agonistic behaviour among adult females was 0.13 interactions per hour. Adult females exhibited a linear hierarchy with a reversal of 10.9%, indicating an unstable relationship; therefore, R. bieti appears to be a relaxed/tolerant species. The lack of a relationship between the agonistic ratio of the adult male towards adult females and their ranks indicated that males did not show increased aggression towards low-ranking females. Differentiated female affiliative relationships were loosely formed in terms of the male, and to some extent influenced by female estrus, implying that relationships between the male and females is influenced by estrus and not rank alone. A positive correlation between the agonistic ratio of adult females and their ranks showed that the degree to which one female negatively impacted others decreased with reduction in rank. Similarly, a positive correlation between the agonistic ratio of females and differences in rank suggests that a female had fewer negative effects on closely ranked individuals than distantly ranked ones. These data indicate that rank may influence relationships between females. A steeper slope of regression between the agonistic ratio and inter-female rank differences indicated that the extent of the power difference in high-ranking females exerting negative effects on low-ranking ones was larger during the mating season than the birth season, suggesting that rank may influence the mating success of females.