Dienstag, 28 März 2023 14:37

MERZ, E. (1978)

Male-male interactions with dead infants in Macaca sylvanus.

Primates 19: 749–754. https://doi.org/10.1007/BF02373640

Arbeit durchgeführt in der Montagne des Singes, Kintzheim


Infants ofMacaca sylvanus are often involved in male-male interactions. Very similar interactions occur also with dead infants. The present paper describes male-male interactions with dead infants and emphasizes similarities and differences between these and those involving live infants. Causation is also briefly discussed.


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Coalitions in male Barbary macaques, Macaca sylvanus: strength, success and rules of thumb.

Animal Behaviour 78 (2): 329-335. https://doi.org/10.1016/j.anbehav.2009.05.010

Arbeit durchgeführt im Affenberg Salem


Several quantitative models of coalition formation assume that a coalition is successful if the strength of the coalition is greater than the strength of the target, but unsuccessful otherwise. However, strong empirical evidence in favour of this hypothesis is still lacking. In this study, we provide an empirical test of this assumption in Barbary macaque males, by using a field-based estimate of individual competitive ability from which coalition strength is derived. Coalition success was determined for 90 coalitions composed of two partners and targeted at one male. Of these, 72.2% were behaviourally successful and 27.8% were unsuccessful. Asymmetry in strength was a significant predictor of coalition success, as this factor alone could explain up to 78.6% of coalition outcomes in the study group. Males behaved as if they were at least partially informed about the nature of this asymmetry. The targets of attacks by coalitions were more likely to counterattack as asymmetry in strength decreased, and coalition partners formed coalitions that produced on average a greater asymmetry in strength than would be expected by chance. However, we provide evidence that males may have used simple rules of thumb based on their knowledge of dyadic and third-party relationships, rather than estimates of asymmetry in strength per se. We conclude that competitive ability is an important factor in coalition formation in Barbary macaque males and discuss additional factors not included in this study, which may account for the unexplained outcomes.


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Intra-specific Variation in the Social Behavior of Barbary macaques (Macaca sylvanus).

Front. Psychol., Sec. Comparative Psychology 12. https://doi.org/10.3389/fpsyg.2021.666166

Arbeit durchgeführt in der La Montagne des Singes Kintzheim, im Tiergarten Nürnberg und im Zoo Cordoba.


Non-human primates show an impressive behavioral diversity, both across and within species. However, the factors explaining intra-specific behavioral variation across groups and individuals are yet understudied. Here, we aimed to assess how group size and living conditions (i.e., captive, semi-free-ranging, wild) are linked to behavioral variation in 5 groups of Barbary macaques (N=137 individuals). In each group, we collected observational data on the time individuals spent in social interactions and on the group dominance style, along with experimental data on social tolerance over food and neophobia. Our results showed that differences in group size predicted differences in the time spent in social interactions, with smaller groups spending a higher proportion of time in close spatial proximity, but a lower proportion of time grooming. Moreover, group size predicted variation in dominance style, with smaller groups being more despotic. Social tolerance was affected by both group size and living conditions, being higher in smaller groups and in groups living in less natural conditions. Finally, individual characteristics also explained variation in social tolerance and neophobia, with socially integrated individuals having higher access to food sources, and higher-ranking ones being more neophobic. Overall, our results support the view that intra-specific variation is a crucial aspect in primate social behavior and call for more comparative studies to better understand the sources of within-species variation.


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Coalition formation among male Barbary macaques (Macaca sylvanus).

Am. J. Primatol. 50 (1):37–51. https://doi.org/10.1002/(SICI)1098-2345(200001)50:1<37::AID-AJP4>3.0.CO;2-3

Arbeit durchgeführt im Affenberg Salem.


A coalition is formed when one animal intervenes in an ongoing conflict between two parties to support one side. Since support of one party is also an act against the other party, coalitions are triadic interactions involving a supporter, a recipient, and a target. The purpose of this study was to test which of three possible theories explains coalition formation among male Barbary macaques: 1) Males support kin to enhance their indirect fitness (kin selection). 2) Males support nonkin to receive future reciprocal support (reciprocal altruism). 3) Males pursue self-interests and immediately benefit via nonkin support (cooperation). Coalition formation was investigated among 31 semi-free male Barbary macaques in the Salem Monkey Park, Germany during the mating season. The results show: 1) Males intervened more often in dyadic conflicts in which a related opponent was involved and supported related opponents more than unrelated opponents. Close kin supported each other more often than distant kin. 2) Some evidence for reciprocal support was found. However, reciprocity was probably a by-product of targeting the same individuals for dominance. 3) Coalition formation among nonkin is best interpreted as cooperation, based on self-interests. Male Barbary macaques seem to intervene more often to stabilize and less often to improve their rank. Although our data were limited, the results revealed that kin support, reciprocal support, and cooperative support were all involved in coalition formation among male Barbary macaques.


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Dienstag, 28 März 2023 13:18

PAUL, A. & KUESTER, J. (1996)

Infant handling by female Barbary macaques (Macaca sylvanus) at Affenberg Salem: testing functional and evolutionary hypotheses.

Behavioral Ecology and Sociobiology 39: 133–145. https://doi.org/10.1007/s002650050275.

Arbeit durchgeführt im Affenberg Salem


Assisting the genetic parents in the rearing of young, a widespread phenomenon in many birds and mammals, is usually regarded as an altruistic or mutualistic behavior. Infant handling by females other than the mother is also common in many primates, but due to high within- and between-species variation and limited knowledge about fitness consequences there is no consensus about its evolutionary and functional significance. Analysis of female infant-handling patterns and its reproductive consequences in three groups of semifree-ranging Barbary macaques revealed that nulliparous females significantly more often handled infants than parous females, but infant handling experience did not affect survival of their own first live-born offspring. Females interacted preferentially with closely related infants, but infant handling frequency improved neither infant survival nor maternal fecundity. Reciprocation of infant handling by mothers was rare. Although “aunting to death” occurred in the population, the hypothesis that infant handling serves to reduce the fitness of competitors was not supported. Limited evidence suggests that females at least sometimes use infants as strategic tools in the course of alliance formation. In concert with this poor evidence for a functional basis of the behavior, several lines of evidence support the hypothesis that infant handling evolved as a non-adaptive by-product of a strong selection for mother-offspring bonding. (1) Rates of infant handling were highest among females that experienced early infant loss. (2) Females caring for infants or yearlings of their own handled other infants significantly less often than females without dependent offspring. (3) Infant handling by females was most prevalent during the infants’ first month of life. (4) Both “aunting to death” and a successful adoption occurred irrespective of kinship relations. Although the by-product hypothesis appears to be the only one able to explain all results of this study, the apparent rarity of infant handling in non-female-bonded species suggest that kin selection is a possible alternative explanation for the evolution of female infant-handling in primates.


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Dienstag, 28 März 2023 13:12


The sociobiology of male–infant interactions in Barbary macaques, Macaca sylvanus.

Animal Behaviour 51 (1): 155-170. https://doi.org/10.1006/anbe.1996.0013.

Arbeit durchgeführt im Affenberg Salem.


Unlike most Old World monkeys, male Barbary macaques frequently associate with and care for infants shortly after birth. Three functional hypotheses have been proposed to explain male–infant interactions in this and other species. (1) The ‘paternal investment hypothesis’ proposes that males invest in their own progeny or otherwise related infants, (2) the ‘mating effort hypothesis’ proposes males care for infants to increase their access to mothers, and (3) the ‘agonistic buffering hypothesis’ proposes that males use infants to regulate their relations with other males. These hypotheses were tested using data on male–infant interactions, paternity and sexual behaviour obtained during a longitudinal study on Barbary macaques living in a large outdoor enclosure. Paternity of 91 infants was determined by DNA fingerprinting. Hypothesis 1 was not supported, because males did not preferentially interact with closely related infants. Similarly, hypothesis 2 was not supported because male caretakers were not more likely to sire the next infant of the mother than non-caretakers. Hypothesis 3 was supported because (1) the direction of at least one type of triadic interactions was significantly biased towards higher-ranking males, (2) the patterning of triadic interactions was strongly dependent on the rank distance between the males, and (3) interaction frequency increased significantly during periods of high inter-male tension. While kin relations were unimportant, the use of infants familiar with the opponent suggests that males make use of their knowledge of relationships between other group members. Beyond agonistic buffering, triadic interactions may serve an important function in coalition formation.


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Dienstag, 28 März 2023 13:08

PAUL, A. & THOMMEN, D. (1984)

Timing of Birth, Female Reproductive Success and Infant Sex Ratio in Semifree-Ranging Barbary Macaques (Macaca sylvanus).

Folia Primatologica 42 (1): 2-16. ISSN: 0015-5713 (Print); eISSN: 1421-9980 (Online).

Arbeit durchgeführt im Affenberg Salem.


Examined were 5 years of data on the reproduction of a semifree-ranging population of Barbary macaques (Macaca sylvanus). In this seasonally breeding species – birth season: mid-March to beginning of August – primiparous 4-year-old females gave birth significantly later in the year than older primiparous and multiparous females, respectively. Multiparous females without an infant from the preceding season gave birth significantly earlier than females who had raised an infant. 88.4% of birth intervals were approximately 1 year, 11.6% about 2 years. Infant loss did not influence the length of the interbirth interval, but after the birth of the next surviving infant the interval was significantly longer. The interval following the 1st infant was significantly longer than after subsequent infants. After the birth of daughters primiparous females had markedly longer birth intervals than after the birth of sons. Infant mortality was 9.1%. Neonatal mortality was influenced by rank and parity of the mother and sex of the infant. Allomothering and aggression by older group members are thought to be the main causes of infant mortality. Female reproduction rates were not dependent on rank. High-ranking females, however, bore their 1st infant significantly earlier than low-ranking females. Low-ranking females had more daughters than sons, in high-ranking females the reverse was found. Differences from findings of other species are discussed with regard to differences in social organization and the reproductive strategies resulting from them.


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Donnerstag, 28 Mai 2015 07:57

BÜSCHING, O. (2014)

Eine Studie zum Verhalten der Berberaffen (Macaca sylvanus) im Opel-Zoo

A study on the behaviour of the Barbary macaques (Macaca sylvanus) in the Opel-Zoo

Lehramt, Wissenschaftliche Hausarbeit

118 Seiten

Didaktik der Biowissenschaften, Goethe-Universität Frankfurt am Main
Leitung: Prof. Dr. Paul Dierkes
Opel-Zoo Kronberg


In dieser Arbeit wurde Studie zum Verhalten der männlichen Berberaffen im Opel-Zoo durchgeführt, um verschiedene Aspekte der Interaktion zwischen Mensch und Affe zu beleuchten und in Beziehung zueinander zu setzen. Die Leitfrage, die sich durch die Untersuchung zieht, ist wie folgt formuliert: Werden bestimmte Verhaltensweisen der beiden männlichen Berberaffen im Opel Zoo von den Besuchern ausgelöst? Zusätzlich zu den Untersuchungen der Mensch-Tier-Interaktionen wurde über einen längeren Zeitraum das Verhalten der Berberaffen in Abwesenheit von Besuchern dokumentiert. Hier konnten Verhaltensänderungen der Tiere mit und ohne Besucher ermittelt, verglichen und in Bezug zueinander gesetzt werden. Für die Studie kamen zwei Methoden zum Einsatz. Während der Vorbereitungsphase wurde mit der Ad libitum- Methode gearbeitet und während der Hauptdatenerhebungsphase kam die Ereignismethode (behavior sampling) zum Einsatz.

Die Ergebnisse zeigen, dass sich die beiden Fokustiere von der Anwesenheit der Besucher generell beeinflussen lassen, sich jedoch in ihrem Verhalten zu den Besuchern sehr unterscheiden. Sie zeigten in vielen Kategorien dieselben Verhaltenselemente, jedoch in anderer Intensität und Häufigkeit. Die gezeigten Verhaltensweisen von den Berberaffenmännchen sind von bestimmten Eigenschaften der Besucher abhängig. Zum einen gibt es Unterschiede im Geschlecht, Alter und Gruppengröße. Zum anderen hat das Verhalten der Besucher, wie beispielsweise ob sie an die Scheibe klopfen, rufen, rennen oder springen, Einfluss auf die Reaktion der Affen.

Sie zeigen keine agonistische Verhaltensweise, wenn nur weibliche erwachsene Menschen vor dem Gehege stehen, sondern überwiegend freundlich-soziales Verhalten, wohingegen die Rivalität hoch ist, wenn sie mit männlichen Erwachsenen konfrontiert werden. Bei Kindern die vor dem Gehege stehen zeigen die Affen die meiste Zeit ein freundliches Verhalten, welches bei Schulklassen abnimmt und sich eher ein agonistisches Verhalten zeigt.


In this work, a lstudy was conducted on the behaviour of male Barbary macaques in the Opel Zoo in 2014 to illuminate various aspects of the interactions between man and ape and their relationship to each other. The main line of questioning running through the investigation went as follows: "Are certain behaviours of the two male monkeys in the Opel Zoo triggered by zoo visitors?" In addition to the investigation on the human-animal interactions, the behaviour of the monkeys in the absence of visitors was documented over a period of time. In this way changes in behaviour of the animals could be determined without visitors, compared and placed in context. Two methods were used for the study. During the preparatory phase the ad libitum-method was used while during the main data aquisition phase we used behaviour sampling.

It was clear to see that the two animals of focus were affected by the presence of visitors, but differed greatly in their behaviour towards visitors. They showed many of the same behaviour elements in each category, but different intensities and frequencies. The shown behaviour of the Barbary Macaque males was dependent on certain characteristics of the visitors. There were differences in gender, age and size of the group. On the other hand, the behaviour of visitors, such as whether they knock on the glass plate, call, run or jump could influence the response of the apes.
They showed no agonistic behaviours when only female adults were present in front of the enclosure, but mostly friendly social behaviour, whereas the competition rose high when they were confronted with adult males. For children facing the enclosure the monkeys behaved friendly, which decreased for school classes and rather changed to agonist behaviour most of the time.


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