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.
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.
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.
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.
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.
Social Behaviour of Striped Hyenas at the Zurich Zoo.
Carnivore 1: 49-60.
Meeting striped hyenas sniff at the mane and the anal pouch of a conspecific, which presents by turning its tail upright and extruding its anal pouch. During agonistic behavior, striped hyenas turn their black throat patches towards one another. Bites are directed against this patch and the legs. Back returning inhibits attack. For optical displays, striped hyenas use their tails, manes and ears. Meet i ng behavior of striped and spotted hyenas is compared and the evolution of anal gland phermones is discussed. Results of this paper suggest that certain subspecies of striped hyenas might forage in small social units.
Social behaviour of pumas in Torres del Paine National Park, Chile.
CAT News 66: 38-39.
Largely studied across the American continent, the puma Puma concolor has been considered a solitary-living species. However, 118 interactions between adult pumas have been documented in Grand Teton National Park NP, USA, providing evidence of unusual social behaviour for this species. In 2016, while filming pumas in Torres del Paine National Park TPNP in Chile, our team documented a total of 11 social interactions between adult and subadult pumas, confirming that the species is not as solitary as thought.
Adaptive social strategies in a solitary carnivore.
Science Advances 3(10). 8 Seiten. DOI: 10.1126/sciadv.1701218
Cost-benefit trade-offs for individuals participating in social behaviors are the basis for current theories on the evolution of social behaviors and societies. However, research on social strategies has largely ignored solitary animals, in which we assume that rare interactions are explained by courtship or territoriality or, in special circumstances, resource distributions or kinship. We used directed network analysis of conspecific tolerance at food sources to provide evidence that a solitary carnivore, the puma (Puma concolor), exhibited adaptive social strategies similar to more social animals. Every puma in our analysis participated in the network, which featured densely connected communities delineated by territorial males. Territorial males also structured social interactions among pumas. Contrary to expectations, conspecific tolerance was best characterized by direct reciprocity, establishing a fitness benefit to individuals that participated in social behaviors. However, reciprocity operated on a longer time scale than in gregarious species. Tolerance was also explained by hierarchical reciprocity, which we defined as network triangles in which one puma (generally male) received tolerance from two others (generally females) that also tolerated each other. Hierarchical reciprocity suggested that males might be cheating females; nevertheless, we suspect that males and females used different fitness currencies. For example, females may have benefited from tolerating males through the maintenance of social niches that support breeding opportunities. Our work contributes evidence of adaptive social strategies in a solitary carnivore and support for the applicability of theories of social behavior across taxa, including solitary species in which they are rarely tested.
Social proximities of developing gorilla males (Gorilla gorilla gorilla) in European zoos: The consequences of castration and social composition.
Applied Animal Behaviour Science 234 (January 2021) 105175. https://doi.org/10.1016/j.applanim.2020.105175
In the European captive population of western lowland gorillas (Gorilla gorilla gorilla), the harem social structure and an even sex ratio at birth result in a surplus of males and consequent management difficulties. This study seeks to assess the socialization differences between captive juvenile and adolescent male gorillas according to their fertility status (intact vs castrated) in different social compositions (familial vs bachelor groups), and to evaluate the suitability of castration as a management tool for the EEP gorilla population. We carried out social network analyses (SNA) to assess the “positive” proximity pattern of behaviour in 93 western lowland gorillas aged from 0 to 45 years old and housed in 11 social units (seven familial and four bachelor groups). We compared the data recorded for the 27 juvenile and adolescent (i.e. subadult and blackback) males included in our sample size. Although no differences were revealed between the intact juveniles and the castrated juveniles living in familial groups, our results showed that castrated adolescent individuals showed more cohesiveness within their familial group than their intact conspecifics in terms of their activity budget. They also displayed a “positive” proximity pattern of behaviour with all group members, including adults (silverback and females). Despite being significantly more isolated, the intact adolescent males living in bachelor groups do not differ from their castrated and intact counterparts of the same age class living in familial groups in terms of their strength of “positive” behaviour when close to group conspecifics. This effect highlights the social benefits of male-male interactions within gorilla species. Our results may be evidence that both of the management strategies compared here, i.e. bachelor groups and castration, could be appropriate socio-behavioural enrichments during juvenility and adolescence. These findings also highlight the need to continue investigations until the study subjects reach adulthood to validate and/or improve these tools for the welfare-compliant management of gorilla male surplus in captivity.
Studie über das Sozial- und Brutverhalten der Zwergflamingos Phoeniconaias minor (Saint-Hilaire, 1798) im Zoologischen Garten Leipzig.
Masterarbeit Univ. Wien. Fakultät für Lebenswissenschaften, Leitung: Ao. Univ.-Prof. Dr. Helmut Kratochvil. 122 Seiten, Ill., Grafiken.
Der Zwergflamingo (Phoeniconaias minor) wird global als „gering gefährdet“ eingestuft. Obwohl einige Populationen als stabil gelten, wird ein weiterer Rückgang vermutet. Viele zoologische Einrichtungen weisen nach jahrzehntelanger Flamingohaltung keine stabilen und selbst-reproduzierenden Zwergflamingopopulationen auf. Folglich sind Importe von tansanischen Zwergflamingos stets erforderlich, was ein weiteres Eingreifen in die Wildpopulationen darstellt und den Druck auf die Etablierung selbst-reproduzierender Zoopopulationen erhöht. Der Zoologische Garten Leipzig hält seit 2004 eine Zwergflamingokolonie. Kontinuierliche Zuchterfolge konnten bis Dato nicht erzielt werden. Der Bruterfolg beschränkt sich auf eine Handaufzucht im Jahr 2008.* Auf Grund dieser Tatsachen und dem stets ungeklärten Phänomen des sporadischen Bruterfolges von Zwergflamingos in Gefangenschaft, wurde eine verhaltensbiologische Studie über das Sozial- und Brutverhalten der Zwergflamingos im Zoo Leipzig durchgeführt. Ziel dieser Studie war es, das Sozial- und Brutverhalten mit dem zusätzlichen Aspekt des ausbleibenden Bruterfolges der Zwergflamingos zu dokumentieren und etwaige Unterschiede zu Freilandstudien aufzuzeigen. Die grundlegenden Aspekte des sozialen Verhaltens, Partnerfindung, Nestbau und Bautätigkeit stimmen mit den Aussagen der zitierten Literatur überein. Diskrepanzen wurden bei der Balz und der Kopulation festgestellt. So konnte die Stimulierung der Schar und die stattfindenden Balzzeremonien nur selten beobachtet werden. Dabei nahmen vermutlich die zu geringe Gruppendynamik, eine zu kleine Anlage bzw. das Fehlen eines separaten Landteils Einfluss auf das Balzverhalten. Eine unzureichende Stimulation zur Brut ist das Ergebnis einer zu kleinen Kolonie und führt zu einem verminderten Bruterfolg. Zusätzlich reagieren die Vögel, bei einer nicht ausreichenden Koloniegröße, sehr empfindlich gegenüber ungewohnten Störungen und brechen das Brüten leichter ab. Diskutabel ist die Eventualität, dass die Haltung von Brutpaaren in einer Innenraumzuchtanlage, welche den Gedrängefaktor erhöht, visuelle Komponenten enthält und Schutz gegen Prädatoren bietet, zum Zuchterfolg der Zwergflamingos beiträgt. Die Flugunfähigkeit führte zu übermäßig fehlgeschlagenen Kopulationen und damit zum Misserfolg der Brut. Der in der Literatur beschriebene Ablauf der Kopulation konnte selten vollständig beobachtet werden. Die Männchen waren größtenteils nicht in der Lage, die Balance auf dem Rücken des Weibchens zu halten. Der Einfluss der Flugunfähigkeit sowie der Geschlechtsreife auf die Erfolgsrate der Brut, werden in dieser Studie diskutiert. Zusammenfassend wurde das Sozial- und Brutverhalten der Vögel analysiert und eine Vielzahl von Stress- und Störfaktoren, welche auf haltungsbedingte Umstände, Wetterverhältnisse oder anthropogene Einflüsse zurückzuführen sind, dokumentiert. Die dargelegten Verbesserungsvorschläge in der Haltung sowie Möglichkeiten zur Optimierungen des Bruterfolges sind das Ergebnis dieser Arbeit.
*Redaktionelle Anmerkung: Ab 2015 waren jährlich Bruten zu verzeichnen. Bis 2022 konnten 53 Junge aufgezogen werden.