Academic literature on the topic 'Crested macaque'

Abstract Although it is well established that female crested macaques (Macaca nigra) display very tolerant social styles, less is known about the extent to which crested macaque males can be characterized by the social style concept. We examined core social style traits and other measures of social interactions in three groups of wild crested macaque males in Tangkoko Reserve, Indonesia. Comparisons with males of other macaque species suggest that they display a mixture of tolerant and despotic indicators, a pattern inconsistent with tolerant, despotic or uniformly intermediate designations. Their apparent avoidance of affiliative interactions and reconciliation involving contact suggest that their relationships also contrast with the typically affiliative and relaxed social style of female crested macaques. Rather than labeling them as distinctly tolerant or despotic, we describe the social style of crested males as ‘avoidant’, which may reflect tense relationships due to high levels of risky reproductive competition.

This study aims to (1) evaluate the habitat quality of Black crested macaque at The Tangkoko Conservation Forest Management Unit, (2) analyze the population density level of Black crested macaque at The Tangkoko Conservation Forest Management Unit, (3) analyze the corelation between habitat quality and Black crested macaque density at The Tangkoko Conservation Forest Management Unit. The study was conducted from July to October 2017 in the Tangkoko Conservation Forest Management Unit, North Sulawesi. The material observed was the Black crested macaque and their habitat. The data collection method used is habitat quality data collection carried out by making sample plots measuring 25 m x 25 m for tree level observations in lanes with each distance between sample plots is 250 m. Data recorded for extraction and dominance of vegetation are species names, number of individuals and breast diameter at breast height. data collection on the density of Black crested macaque is done by way of inventorying animals directly through surveys in the field. Observations are carried out by walking at speeds of 1 - 1.5 km / h on each track and stopping at every 100 m to hear and observe the surroundings.Observations are carried out in the morning (6:00 - 11:00) and in the afternoon (14:00 - 17:00). Data recorded is the number of individuals found using the line transect method. Data analysis used (1) Important value index (INP) is a quantitative parameter that can be used to express the level of dominance (level of mastery) of species in the tree community. (2) Analysis of individual density is carried out according to the meeting of individuals in the group during observation (3) Parametric statistical tests ofPearson correlation. The results showed that (1) habitat quality parameters analyzed were important value index with the highest value of 95.63% in Cananga odorata on line A1; (2) the population density level of Black crested macaque was 9.66 individuals / km2. The highest amount of density is found on the T1 line where the T1 line is located in the Batuputih Tourism Park which routinely gets tourist visits. There are two pathways that are not found in the Black crested macaque namely T10 and A2 lines; (3) Based on the Pearson correlation analysis showed that the correlation between habitat quality and density of Black crested macaque that shows a positive value.*eprm*

AbstractThe crested black macaque Macaca nigra, endemic to Sulawesi, Indonesia, is categorized as Critically Endangered on the IUCN Red List and its population in the Tangkoko Nature Reserve is probably the only viable one within its native range. Earlier studies suggested that this population suffered a decline of 75% during 1978–1994. To evaluate its current status we conducted a line transect survey in the Reserve and assessed effects of ecological and anthropogenic variables on macaque abundance and distribution. We estimated a density of 44.9 individuals km-2 (95% confidence interval, CI, 25.6–78.8) and a total population of 1,951 individuals (CI 1,113–3,421). This estimate of density is 35% lower than that of 68.7 individuals km-2 in 1994. There were moderate to strong correlations between macaque abundance and vegetation structure (basal area and canopy tree density). We observed illegal logging in the area and therefore habitat quality for macaques may be indirectly affected by illegal human activities. If our population estimate is projected linearly M. nigra could become extinct in Tangkoko within 46 years, highlighting the urgent need to improve management of illegal hunting and logging in the Reserve.

A research about gestational length of Sulawesi crested black macaque (Macaca nigra) has conducted to determine the length between conception and birth. Five adult females of Rambo II Group at Tangkoko-Batuangus Nature Reserve, North Sulawesi, were used as samples. Data collection used focal animal sampling to observe the sex swelling cycle and the time when they gave birth. The length of gestation was determined by counting the time duration between middle fully swollen until giving birth. Data was analyzed descriptively to count the mean and standard deviation. Result showed that the gestational length of Sulawesi crested black macaque was 183.6 ± 11.6 days. From this result can be concluded that the gestational length of this species is longer than other Macaca species.

Macaca nigra (kera jambul hitam) adalah salah satu satwa endemik di Pulau Sulawesi yang populasinya di alam semakin berkurang. Menurunnya populasi satwa ini utamanya disebabkan oleh meningkatnya populasi penduduk yang secara tidak langsung mempengaruhi tingkat perburuan satwa ini, yang umumnya dikonsumsi sebagai makanan tradisional masyarakat setempat. Perburuan ini dilakukan semata-mata hanya untuk tujuan komersial. Akses jalan Trans-Sulawesi yang semakin baik juga telah membuka peluang yang lebih besar bagi para pemburu dan pedagang dalam melakukan perdagangan satwa liar. Selain itu, status kawasan, lemahnya penegakan hukum, minimnya sumberdaya manusia pengelola kawasan, dan lemahnya manajemen kawasan serta aktivitas wisata yang tidak bertanggung jawab juga turut berperan dalam menurunnya populasi kera jambul hitam. Tulisan ini mencoba untuk mengetengahkan isu-isu yang mempengaruhi populasi M. nigra di alam dan mengidentifikasi tantangan-tantangan yang harus dihadapi dalam konservasi satwa ini. Rekomendasi untuk mempertahankan populasi dan melestarikan satwa ini juga dibahas dalam tulisan ini. Key words: wild meat, wildlife trade, wildlife tourism, north sulawesi References

AbstractPrimates are one of the most threatened groups of mammals. Understanding their patterns of population occurrence and abundance, especially in response to threats, is critical for informing conservation action. The crested black macaque Macaca nigra is the only Critically Endangered species of Sulawesi's seven endemic macaques. Little is known about its distribution or its response to deforestation and hunting. We conducted a camera-trap survey across the entire species range using an occupancy-based analytical approach to (1) establish the first range-wide baseline of occurrence, (2) investigate how environmental and anthropogenic factors influence occurrence, (3) identify priority conservation subpopulations, and (4) test the efficacy of the sampling and analytical protocol for temporal monitoring of M. nigra using occupancy as the state variable. From 9,753 camera-trap days, M. nigra was detected on 473 days at 77 of the 111 camera locations. Species occupancy was 0.66 and highest inside protected areas and closed canopy forest. We identified eight distinct subpopulations, based on distribution and forest fragment size. To inform future monitoring, we used a power analysis to determine if our effort would allow us to detect inter-annual occupancy declines of 10%, and found that 90 camera locations surveyed for 3 months (8,100 camera days) across three consecutive seasons is the effort required to detect such change with 80% certainty. Our study underscores the importance of well-managed protected areas and intact forests for the long-term survival of the crested black macaque, and tests the effectiveness of camera traps to monitor primates at the landscape scale.

Crested macaque (Macaca nigra), one of the seven endemic primates in Sulawesi is the most endangered macaque species that has been categorized as critically endangered by International Union for Conservation of Nature (IUCN). However, almost nothing is known about the reproductive biology in associated with the behavioral during pregnancy. The data is important to support a management and breeding programs such as pregnancy diagnostic and conservation program in this species. The research aimed was to study the behavior of the crested macaques during pregnancy. Observations were performed on the 10 adult females of the group of Rambo 1 (R1) which has been habituated at Tangkoko-Batuangus Nature Reserve, North Sulawesi. Behavioral data were collected using focal animal sampling and recorded using instantanaeous sampling on females during menstrual cycling, pregnancy, and after parturition (lactation). During five months observations, a total of 393.63 observation hours were recorded. The results showed that daily activities of the M. nigra during menstrual cycling were dominated by feeding (26.60%), foraging (15.95%), and locomotion (16.16%). Daily activities during pregnancy was dominated by feeding (27.03%), foraging (16.37%), and resting (13.45%), whereas after parturition (lactation) period is dominated by resting (26.12%), foraging (19.51%), and feeding (14.98%). The resting was the most activity in the end of pregnancy and few day after parturition. The diets were collected successfully composed of the fruits (34 species), arthropods (3 species, 2 families, 4 orders), fungi (4 genus), and plants (5 species). Climate was influenced on the composition of the diet, especially on fruit and arthropods. In conclusion, the activity budgets were different during menstrual cycling, pregnancy, and lactation, especially feeding, foraging, locomotion, and resting.

Crested macaque live in multimale-multifemale social groups where temporary association (consortship) typically occurs. Current theory and these limited qualitative observations suggest the hypothesis that behavior functions as a means for males to gain access to fertile females. The aim of this study was to investigate follower status based on quantitative method. Males were classified as either “consort males,” “followers,” and “non-followers” based on proximity maintanance every 15 minute uses scan sampling. Tactics used by followers were classified into 1) individual challenge, 2) coalitionary challenge, 3) abandoned takeover, and 4) opportunistic takeover. The proportion of successful takeovers by followers was calculated by dividing the number of takeovers by followers by the total number of observed takeovers. The proportion of followers is higher than average on D-5 and earlier, D-4, and D-3. Only two of the four consort takeover tactics were used by followers. For abandoned which made up 40% and for individual tactic was made up to 11.5% of consort takeovers tactic used. This study contribute to our understanding of alternative mating strategy in primate and provide the first quantitative data demonstrating that following is an alternative mating strategy in crested macaque (Macaca nigra).

Direct fitness is measured as the number of surviving offspring. Thus adult males may try to produce as many offspring as possible or to increase the survival of their offspring. Recent findings have shown the many potential benefits of fathers’ presence and support on infants’ development and survival. However, little is known about the influence of socio-ecological factors on male-infant interactions. The main aim of this thesis was therefore to investigate male-infant interactions in wild crested macaques (Macaca nigra). In particular, we aimed to examine the affiliative and agonistic interactions taking place in this species, along with the factors influencing these interactions and offspring survival. Data collection for this thesis took place in the Tangkoko-Duasudara Reserve in Sulawesi, Indonesia, on 3 wild groups of crested macaques. For the first study, data were collected on migrations, births, disappearances, and encounters between groups over 5 years. We analyzed the influence of socio-ecological factors (e.g. rainfall, alpha-male position takeover, and male hierarchy stability) on pre- and post-natal loss. The results showed that high infant mortality was mainly associated to male alpha-position takeover, which suggests that infanticide may indeed occur in this species. In addition, we found that female within-group competition for food sources and between-group resource defense influenced fetal and infant loss. Based on these findings, we were interested to see whether fathers protected their own offspring against male attacks. Thus, in the second study, we investigated the social determinants and characteristics of male-infant affiliations. Our results indicate that adult males and infants form preferential association, and that infants initiate the majority of male-infant affiliations. Infants initiated affiliations mainly towards a high ranking male or a male in a close relationship with their mother. In addition, infants affiliated mainly with adult males in the absence of their mother, while males affiliated mostly with infants when the infants‘ mother was present in proximity. Furthermore, males initiated affiliations towards an infant when they held a high rank or when they had a strong bond with the infant‘s mother. Interestingly, paternity did not affect male-infant affiliations. In conclusion, these studies provide insights in the specifics of both infant survival strategies and male reproductive strategies. In addition, we show that infants are active agents in establishing and maintaining preferential relationships with males. This thesis, thus, confirm that male-infant interactions, although rare, have a strong influence both on males’ and infants’ direct fitness.

Dominance rank often determines the share of reproduction an individual male can secure in group-living animals (i.e. dominance rank-based reproductive skew). However, our knowledge of the interplay between individual and social factors in determining rank trajectories of males is still limited. The overall aim of this thesis was therefore to investigate mechanisms that underlie individual dominance rank trajectories in male crested macaques (Macaca nigra) and to highlight potential individual and social determinants of how males can achieve and maintain the highest rank possible. Data for this thesis were collected on 37 males during a field study on a natural population of crested macaques living in the Tangkoko-Batuangus Nature Reserve in Indonesia. In study 1, I validate Elo-rating as a particularly well suited method to quantify dominance hierarchies in animal species with dynamic dominance relationships. In studies 2 and 3, I suggest a personality structure for crested macaque males consisting of five distinct factors and further demonstrate that two personality factors determine whether males will rise or fall in rank. Finally, in study 4, I present results on how males utilize coalitions to increase their future rank. Together, these results shed light on how individual attributes and social environment both can impact male careers. Ultimately, in order to understand what determines rank-based reproductive skew, we need to consider the complexity and likely diversity of the mechanisms underlying rank trajectories of individual males which are likely to differ across different species.

Comparative research into animal communication has been and continues to be highly informative regarding the general principles underlying the evolution of communication (including human communication). However, our tendency to focus on specific modes of production of these signals (i.e. facial expressions, gestures or vocalisations) in isolation of each other, and in a limited number of species, may be obstructing our progress. Therefore, in this thesis, I adopted a novel and more comprehensive approach to a highly understudied primate, the crested macaques (Macaca nigra). First, I consider the effects of the strength of social bonds and dominance relationships between individuals (and, when possible, their kin relationships) when investigating the function of communicative signals. The findings show that communication can be flexible depending on social factors, possibly reflecting functional relevance to the context. Social bonds in particular, influenced communication between individuals facing immediate socio-ecological challenges (finding food and deterring predators). Second, I address the significance of multimodal communication in this species. I test the influence of the composition of communicative signals on the outcome of social interactions. The results show that subtle changes in the composition of communicative signals (multicomponent and multimodal) can have a profound effect on the outcome of social interactions. The findings resulting from this work constitute one of the first quantitative accounts of the communication system of crested macaques, thereby adding to the pool of data available to study communication from a comparative perspective. The comprehensive approach adopted in this thesis provides much needed insight into the importance of considering communication as multimodal and highly intertwined with species’ social style. Such an approach seems highly productive and provides insight into aspects of social and communicative complexity that have been overlooked so far.

Direct fitness is measured as the number of surviving offspring. Thus adult males may try to produce as many offspring as possible or to increase the survival of their offspring. Recent findings have shown the many potential benefits of fathers’ presence and support on infants’ development and survival. However, little is known about the influence of socio-ecological factors on male-infant interactions. The main aim of this thesis was therefore to investigate male-infant interactions in wild crested macaques (Macaca nigra). In particular, we aimed to examine the affiliative and agonistic interactions taking place in this species, along with the factors influencing these interactions and offspring survival. Data collection for this thesis took place in the Tangkoko-Duasudara Reserve in Sulawesi, Indonesia, on 3 wild groups of crested macaques. For the first study, data were collected on migrations, births, disappearances, and encounters between groups over 5 years. We analyzed the influence of socio-ecological factors (e.g. rainfall, alpha-male position takeover, and male hierarchy stability) on pre- and post-natal loss. The results showed that high infant mortality was mainly associated to male alpha-position takeover, which suggests that infanticide may indeed occur in this species. In addition, we found that female within-group competition for food sources and between-group resource defense influenced fetal and infant loss. Based on these findings, we were interested to see whether fathers protected their own offspring against male attacks. Thus, in the second study, we investigated the social determinants and characteristics of male-infant affiliations. Our results indicate that adult males and infants form preferential association, and that infants initiate the majority of male-infant affiliations. Infants initiated affiliations mainly towards a high ranking male or a male in a close relationship with their mother. In addition, infants affiliated mainly with adult males in the absence of their mother, while males affiliated mostly with infants when the infants‘ mother was present in proximity. Furthermore, males initiated affiliations towards an infant when they held a high rank or when they had a strong bond with the infant‘s mother. Interestingly, paternity did not affect male-infant affiliations. In conclusion, these studies provide insights in the specifics of both infant survival strategies and male reproductive strategies. In addition, we show that infants are active agents in establishing and maintaining preferential relationships with males. This thesis, thus, confirm that male-infant interactions, although rare, have a strong influence both on males’ and infants’ direct fitness.:Contents ........................................................................................................................................ 5 List of Figures .............................................................................................................................. 7 List of Tables ................................................................................................................................ 8 Summary ....................................................................................................................................... 9 Zusammenfassung .................................................................................................................. 13 1 General Introduction .......................................................................................................... 17 1.1 Infants and adult males in mammals ...................................................................... 18 1.2 Primate males’ use and abuse of infants ................................................................ 19 1.3 Male care and paternal care in primates ............................................................... 20 1.4 Crested macaques as study species ......................................................................... 21 1.5 Aims of this thesis ........................................................................................................... 23 2 Social and ecological factors influencing offspring survival in wild macaques ................................................................................................................................... 25 2.1 Abstract ............................................................................................................................... 26 2.2 Introduction ...................................................................................................................... 26 2.3 Methods .............................................................................................................................. 29 2.4 Results ................................................................................................................................. 34 2.5 Discussion .......................................................................................................................... 37 3 Mother-male bond, but not paternity, influences male-infant affiliation in wild crested macaques .......................................................................................................... 45 3.1 Abstract ............................................................................................................................... 46 3.2 Introduction ...................................................................................................................... 46 3.3 Methods .............................................................................................................................. 50 3.4 Results ................................................................................................................................. 58 3.5 Discussion .......................................................................................................................... 61 4 Thesis Conclusion ................................................................................................................ 71 Appendices ................................................................................................................................ 75 Supplementary figure and tables for Chapter 2 ......................................................... 76 Supplementary methods and tables for Chapter 3 ................................................... 79 Bibliography ............................................................................................................................. 83 Acknowledgements ................................................................................................................ 99 Contributions of co-authors .............................................................................................. 101 Curriculum vitae .................................................................................................................... 105 Publications and conference contributions ................................................................. 107 Selbstständigkeitserklärung ............................................................................................. 109

Sozialität ist vorteilhaft für Individuen. Sozialbeziehungen zwischen Individuen können als langfristige Investitionen betrachtet werden, die letztlich individuelle Fitness beeinflussen. Die Analyse der Kosten und Nutzen von Sozialbeziehungen kann daher dazu dienen, herauszufinden wie Individuen mit den Kosten (Wettbewerb) und Vorteilen (Kooperation) vom Gruppenleben umgehen. Theoretische Modelle, die zur Erklärung der existierenden Diversität von Sozialstrukturen im Tierreich dienen, basieren auf der Analyse ökologischer, genetischer, ontogenetischer, phylogenetischer und anderer sozialer Faktoren. In Säugetieren entwickeln Weibchen häufig intensive soziale Bindungen. Diese Bindungen werden häufig stark von Dominanz- und Verwandtschaftsbeziehungen geprägt, was wiederum Konsequenzen hat für Kooperation im Allgemeinen. Es ist jedoch noch größtenteils unklar, wie Unterschiede in der Stärke und Qualität von solchen sozialen Bindungen auftreten, insbesondere in Bezug auf den Typ der Gesellschaft in der sie auftreten, beispielsweise ob eine Gesellschaft eher despotisch oder egalitär organisiert ist. Obwohl alle Makakenarten (Gattung Macaca) eine gemeinsame Art von sozialer Organisation teilen (Mehrmännchen/Mehrweibchen Gruppen, Philopatrie der Weibchen), treten gleichzeitig markante Unterschiede im Sozialverhalten zwischen den einzelnen Arten auf. Die Unterschiede wurden anhand verschiedener Faktoren erklärt, die von Ökologie bis hin zu Phylogenie reichen, was wiederum zur Klassifizierung der Arten in verschiedene Kategorien führte. Ein Problem dabei ist, jedoch, dass bisher nur einige wenige Makakenarten sehr intensiv erforscht wurden, während viele andere Arten bisher stark vernachlässigt wurden. Diese Unausgeglichenheit unterhöhlt unser Verständnis der Diversität der verschiedenen Sozialsysteme. Das übergeordnete Ziel dieser Arbeit ist es, durch die Erforschung einer der bisher weniger bekannten Arten, dem Schopfmakaken M. nigra, unser Wissen und Verständnis über die Verhaltensdiversität innerhalb der Makaken zu erweitern. Das erste untergeordnete Ziel dieser Arbeit ist es, den Grad sozialer Toleranz zwischen Weibchen zu quantifizieren (Studie 1). Danach erläutere ich die Struktur und Funktion von Sozialbeziehungen zwischen Weibchen. Ich beschreibe die Interaktionen die direkt nach Konflikten stattfinden (Studie 2), und untersuche den Einfluss von Dominanz- und Verwandtschaftsbeziehungen auf Sozialverhalten (Studie 3). Insgesamt können die Ergebnisse dieser Arbeit dazu beitragen, das Zusammenspiel verschiedener Faktoren besser zu verstehen, insbesondere durch den Vergleich der in Schopfmakaken gefundenen Muster mit denen anderer Arten. Darauf aufbauend wird ein theoretischer Rahmen vorgeschlagen, der die Evolution unterschiedlicher Sozialstrukturen im Tierreich zu vereinen sucht. In der ersten Studie quantifiziere ich eine umfangreiche Reihe von Verhaltensparametern, die dazu geeignet sind den sozialen Stil einer Art zu bestimmen. Die Ergebnisse dieser Studie bestätigen einen toleranten sozialen Stil weiblicher Schopfmakaken, der sich durch Konflikte mit niedriger Intensität, häufiger bidirektionalität, und versöhnung ausdrückt. Asymmetrie in Dominanzbeziehungen ist moderat, was unter anderem durch den bidirektionalen und affiliativen Gebrauch der bared-teeth Geste ausgedrückt wird. Weiterhin tolerieren Weibchen gegenseitige räumliche Nähe. Diese Muster stimmen mit denen anderer toleranter Makakenarten überein und liegen außerhalb der für despotische Arten beschriebenen Variation. In der zweiten Studie untersuche ich die Determinanten und Funktionen von Interaktionen die nach Konflikten stattfinden. Die Kosten von Aggression werden durch Verhaltensindikatoren für Stress gemessen. Weiterhin untersuche ich, ob Charakteristika von Konflikten (z.B. Intensität, Entschiedenheit, Kontext) und der beteiligten Paare (Stärke der sozialen Bande, Häufigkeit von Unterstützung in Konflikten), das Auftreten von Interaktionen nach einem Konflikt beeinflussen. Dabei teste ich vier mögliche Funktionen von nach-Konflikt-Interaktionen. Wenig spricht dafür, dass Aggression Kosten beinhaltet, gemessen durch Verhaltensindikatoren für Stress. Es scheint deshalb unwahrscheinlich, dass Interaktionen nach einem Konflikt dazu dienen solchen Stress zu reduzieren. Ebenso unwahrscheinlich scheint es, dass solche Interaktionen dazu dienen die Beziehung zwischen den Tieren zu „reparieren“. Im Gegensatz dazu unterstützen die Muster der Initiationen und Richtungen der nach-Konflikt Interaktionen die Hypothese, dass Versöhnung ein Signal für freundliche Intention ist, und dass Interaktionen mit Dritten dem Schutz vor erneuter Aggression dienen. Auch diese Ergebnisse weisen auf den toleranten sozialen Stil von Schopfmakaken hin und kontrastieren mit den Ergebnissen von Studien anderer Makaken- und Tierarten. Die abschließende Studie beschreibt den Einfluss von Dominanz und Verwandtschaft auf Sozialbeziehungen. Dafür untersuche ich Verbindungen zwischen Dominanz, Verwandtschaft, Alter, sozialen Bindungen, Unterstützung in Konflikten, und soziale Toleranz (Versöhnung und Nahrungsaufnahme in der Nähe anderer Individuen). Die Ergebnisse zeigen, dass hochrangige Weibchen als soziale Partner nicht attraktiver sind als niederrangige Weibchen, und dass Dominanzbeziehungen unabhängig vom Verwandtschaftsgrad sind. Weiterhin kann ich zeigen, dass die stärksten sozialen Bindungen zwischen verwandten Weibchen auftreten, die einen ähnlichen Rang haben und gleichaltrig sind. Im Gegensatz dazu, tritt Unterstützung in Konflikten am häufigsten zwischen Tieren gleichen Ranges und Alters auf, unabhängig vom Verwandtschaftsgrad und der Stärke der sozialen Bindung. Des weiteren konnte keine Beziehung zwischen den getesteten Parametern und sozialer Toleranz gefunden werden. Diese differenzierten Effekte von Beziehungs-Charakteristika unterstreichen die Komplexität des sozialen Lebens in Schopfmakaken. In solch toleranten Gesellschaften formen Weibchen weitreichende und diversifizierte Netzwerke. Durch die Kombination von Verhaltens- und genetischen Daten, stellt diese Arbeit die erste umfassende Studie über Sozialverhalten unter natürlichen Bedingungen dar, an einer Art über die bisher relativ wenig bekannt ist. Die erste Studie unterstützt die Idee, dass soziale Stile als „Cluster“ von sozialen Verhaltensweisen betrachtet werden können. Diese Cluster variieren um einen Modalwert und ähneln sich innerhalb von Arten mehr als zwischen Arten und Gruppen von Arten. Damit können sie auch als coping Strategien oder Verhaltenssyndrome betrachtet werden. Weiterhin konnte der geringe Einfluss von Dominanz- und Verwandtschaftsbeziehungen auf die Stärke von sozialen Bindungen nachgewiesen werden, sowie die Abwesenheit eines Effektes der Stärke von sozialen Bindungen auf Koalitionen, Versöhnung, und Nahrungsaufnahme in der Nähe anderer Individuen. Diese Ergebnisse werfen die Frage auf, welchen adaptiven Wert starke soziale Bindungen haben, angesichts ihrer Diversität in Arten in denen soziale Netzwerke gebildet werden. Es kann daher angenommen werden, dass solche Unterschiede zwischen toleranten und despotischen Strategien im evolutionären Kontext bedeutungsvoll waren. Die vorherrschenden Theorien sozialer Evolution können einen großen Teil der auftretenden Variation im Sozialverhalten nicht ausreichend erklären. Mit dieser Arbeit schlage ich deshalb vor, soziale Stile von Makaken besser als coping Strategien oder Verhaltenssyndrome zu betrachten, die sich evolutiv entwickelten, um letztlich die Probleme zu lösen, die mit dem Leben in sozialen Gruppen einhergehen. Im Rahmen von Verhaltenssyndromen betrachtet können nicht nur verschiedene Verhaltensstrategien in verschiedenen Kontexten und zwischen verschiedenen Individuen erklärt werden, sondern diese erlauben ebenfalls die Integration von Ansätzen um gleichzeitig proximate Mechanismen, ultimate Funktionen, und Ontogenie von Verhalten zu untersuchen. Die Ergebnisse dieser Arbeit sollten in folgenden Studien durch Quantifizierung weiterer ökologischer (bspw. Wettbewerb um Zugang zur Nahrung) und sozialer Einflussfaktoren (bspw. Männchen) ergänzt werden. Insgesamt weicht das Sozialverhalten von Schopfmakaken, wie ich in dieser Arbeit beschreibe, substantiell von dem ab, was normalerweise als typisch für cercopithecine Primaten angesehen wird. Dies unterstreicht letztlich die Wichtigkeit, sowohl externe (Umwelt), als auch interne Komponenten (Sozialsystem) zu betrachten, um die Diversität von Tiergesellschaften zu erklären.
La vie sociale est extrêmement bénéfique pour les individus. Les relations sociales entre individus, compétitives et coopératives, sont considérées comme des investissements à long-terme influençant leur valeur adaptative. L’analyse des coûts (compétition) et bénéfices (coopération) de la vie sociale à ce niveau permets donc de determiner les stratégies comportementales des individus, qui sont très diverses. Pour expliquer cette diversité dans les structures sociales animales, les modèles d’évolution sociale prennent en compte l’influence de facteurs écologiques, génétiques, sociaux, développementaux et l’histoire phylogénétique des espèces. Chez les mammifères sociaux, les femelles, étant philopatriques, forment des liens sociaux forts. Ces liens peuvent être influencés par les relations de dominance et le degré de parenté. La variation dans la force et la diversité des relations sociales a d’importantes implications pour la coopération entre femelles. Cependant, les facteurs déterminant cette variation restent ambigus, surtout en relation avec le type de société dans laquelle les femelles vivent, par exemple despotique ou égalitaire. Les macaques (genre Macaca) partagent la même organisation sociale (groupes multi-males multi-femelles où les femelles sont philopatriques), mais les relations sociales des différentes espèces varient largement. Ces différences sont expliquées par différent facteurs, de l’écologie à la covariation des caractères, et ont généré plusieurs classifications des structures sociales. Un problème majeur est le manque de connaissance de certaines espèces au détriment d’autres qui empêche une compréhension exhaustive de la diversité sociale des macaques. L’objectif principal de ma thèse est donc d’approfondir la connaissance de la diversité sociale des macaques par l’étude détaillée d’une des espèces les moins connues, les macaques à crête de Sulawesi, M. nigra, dans son milieu naturel. Ma 1ère étude consiste à évaluer le style social des femelles. J’examine ensuite de manière approfondie la structure et la fonction des relations sociales par l’étude des interactions conciliatoires (2ème étude) et de l’influence de la dominance et de la parenté sur les interactions sociales (3ème étude). Finalement, je propose une réflexion sur l’interaction des facteurs diverses dans une perspective comparative et une idée de modèle permettant une prise en compte globale de ces facteurs dans l’évolution de la diversité sociale. Dans la première étude, j’évalue un ensemble de comportements sociaux dont la variation est liée au degré de tolérance d’une espèce. Je confirme que les femelles macaque à crête ont un style social tolérant avec des conflits de faible intensité, souvent bidirectionnels et réconciliés. L’asymétrie de dominance est modérée et associée à une mimique faciale positive et également bidirectionnelle. De plus, les femelles ont une grande tolérance des autres à proximité. Ces observations concordent avec ce qui a été observé chez les autres macaques tolérants et contrastent avec les macaques plus despotiques. Dans la deuxième étude, j’examine les facteurs déterminants et la fonction des interactions post-agression. J’analyse les conséquences de l’agression sur l’anxiété des femelles. J’étudie ensuite l’influence des caractéristiques des conflits (intensité, direction ou contexte) et de celles des dyades impliquées sur l’occurrence des interactions post-agression afin de déterminer leur fonction. Les agressions ne semblent pas perçues comme anxiogènes. En conséquence, les interactions post-agression ne semblent pas fonctionner pour réduire l’anxiété perçue des opposants. Je n’ai pu trouver qu’un support partiel à la théorie selon laquelle les femelles utilisent les interactions post-agression pour “raccommoder” leurs relations sociales. L’initiation et la direction des interactions post-agression révèlent plutôt que la réconciliation pourrait fonctionner comme un signal d’intention pacifique et que les agressions secondaires pourraient fonctionner pour réaffirmer le rang hiérarchique des opposants initiaux. Ces observations, très distinctes de ce qui est généralement observé chez les autres macaques et animaux sociaux, sont à mettre en relation avec le style social tolérant de cette espèce. Finalement, la troisième étude a pour objectif de déterminer l’influence des relations de dominance et de la parenté sur les interactions sociales. J’analyse les liens entre la dominance, la parenté, l’âge, les liens sociaux, les coalitions, le niveau de tolérance sociale (réconciliation et proximité autour de ressources alimentaires). Je ne trouve pas de lien entre les différences de rang hiérarchique et le degré de parenté. Je mets en évidence que les femelles appartenant à la même classe d’âge ainsi que les femelles à la fois proches en rang de dominance et apparentées ont les liens sociaux les plus forts. Les coalitions sont formées entre femelles appartenant à des classes d’âge différentes ou proches en dominance, mais pas entre apparentées ou entre femelles avec des liens forts. De plus, le degré de tolérance n’est influencé par aucune des variables analysées. Les effets différents des variables analysées sur plusieurs des plus importants paramètres sociaux censés influencer la valeur adaptative des femelles met en évidence la complexité des relations sociales dans les sociétés tolérantes, qui forment des réseaux sociaux diverses et variés. En combinant des variables comportementales et génétiques, ma thèse constitue l’étude la plus exhaustive du comportement social des femelles d’une espèce de macaque peu connue en milieu naturel. Elle apporte de nouvelles perspectives empiriques essentielles pour l’étude de la variation sociale. En confirmant le style social tolérant des femelles macaque à crête, la première étude étaye la thèse selon laquelle les styles sociaux sont des associations constantes de comportements, analogues aux syndromes comportementaux. Je démontre aussi l’influence limitée de la dominance ou de la parenté sur les relations sociales des femelles. Le degré de parenté ainsi que la force des liens sociaux, déterminants majeurs de la coopération, n’expliquent pas la fréquence des coalitions, ou le degré de tolérance sociale. Ces résultats questionnent l’importance de la force des liens sociaux par rapport à sa diversité. Ils indiquent aussi que les différences entre stratégies sociales sont significatives au niveau évolutif. Les théories actuelles sur l’évolution sociale ne sont pas entièrement satisfaisantes parce qu’une grande part de la variation observée dans les comportements sociaux restent inexpliquée. Je propose de considérer les styles sociaux comme des syndromes comportementaux, ayant évolués différemment pour résoudre le même problème: comment tirer tous les bénéfices de vivre en groupe. Finalement, le cadre théorique des syndromes comportementaux permet de prendre en compte de nombreux facteurs à la fois et de faire le lien entre eux afin d’expliquer globalement la diversité sociale. Mes résultats restent à mettre en relation de manière plus approfondie avec d’autres facteurs sociaux (comme le comportement des males) et écologiques (comme la compétition alimentaire). Néanmoins, le portrait des comportements sociaux des femelles macaque à crête tracé dans cette thèse diffère substantiellement du modèle traditionnel des primates cercopithecines. Cela démontre l’importance d’intégrer au sein d’un seul modèle d’évolution sociale tous les composants (l’environnement, l’organisme et le système social) pour mieux comprendre la diversité des sociétés animales.