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.
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.
Ruhe und Schlaf bei Säugetieren.
Neue Brehm-Bücherei 338. Wittenberg (A. Ziemsen) 1965; 160 S., 50 Abb.
Die Verfasserin hat auf Grund jahrelanger Studien sich die Aufgabe gestellt, die biologische Bedeutung sowie alle mit dem Ruheverhalten zusammenhängenden Fragen zu untersuchen. Während der Ruhe, die sich mit einer Restitution des Nervensystems verbindet, nehmen die Tiere, deren Ruhebedürfnis von vielen Bedingungen ihrer Lebensweise und des Stoffwechsels abhängt, unterschiedliche Stellungen ein, um eine Entlastung einzelner Körperteile und eine allgemeine Entspannung am besten herbeizuführen. Maßgebliche Faktoren sind auch der Schutz vor schädlichen Witterungseinflüssen und vor Feinden. Oft werden Tarnstellungen eingenommen. Bei manchen Gruppen ist die mehr oder weniger modifizierte Embryonalstellung offenbar die vorherrschende Schlaf- und Ruhehaltung geblieben. Vielfach sind diese Stellungen und Verhaltensabläufe stammesgeschichtlich zu erklären. So deuten die Umdrehungen eines Hundes vor dem Niederlegen auf das Zubereiten des Lagers im hohen Steppengras hin. Baumleben und Leben im Wasser führen zu besonderen Anpassungen bei den Ruhestellungen. Bei Haus- und Zootieren hat der Mensch vielfach in das Ruhe- und Schlafbedürfnis eingegriffen; manche Tierarten sind unter dem Einfluß menschlicher Störungen zu Dämmerungs- und Nachttieren geworden. Das Ruheverhalten unterliegt einem 24-Stunden-Rhythmus, dem die Forschung in den letzten Jahren intensive Studien gewidmet hat. Die Verfasserin hat ihre Untersuchungen vor allem unter verhaltenskundlichen Gesichtspunkten durchgeführt. Sie zeigt uns, was man aus der nachdenklichen Betrachtung ruhender Tiere, die man gewöhnlich kaum beachtet, alles lernen kann. Wer dieses Bändchen gelesen hat und mit offenen Augen Tiere beobachtet, findet das Leben in all seiner Vielfalt auch im Schlafe!
Beobachtungen zur Aktivitätsverteilung und zum Ruheverhalten der afrikanischen Nashörner, Diceros bicornis (Linné, 1758) und Ceratotherium simum (Burchell, 1817), des Zürcher Zoos.
Zool. Garten N.F. 90 (2022): 161-182. doi:10.53188/zg008
Überarbeitete Fassung des nicht veröffentlichten Abschlussberichts vom 31.12.1970.
Es wurden 1,1 Ceratotherium simum simum und 0,2 Diceros bicornis michaeli des Zürcher Zoos während jeweils fünf Tagen und fünf Nächten hinsichtlich der Aktivitätsverteilung und des Schlafverhaltens beobachtet, wobei die Nachtbeobachtungen mit Hilfe eines Infrarot-Nachtsichtgeräts durchgeführt wurden.
Es werden einige qualitative Verhaltensbeobachtungen kurz beschrieben und mit Fotomaterial belegt. Die quantitativen Erhebungen ergaben einen sehr hohen, für die beiden Arten unterschiedlichen Anteil des Ruheverhaltens am Aktogramm (Breitmaulnashorn 64 %, Spitzmaulnashorn 52 %), das Vorhandensein einer biphasischen Aktivitätskurve bei beiden Arten mit Höhepunkten der Aktivität von 8-11 und von 14-17 Uhr, die Unterteilung der Ruhephasen in Intervalle von selten mehr als drei Stunden, ein regelmäßiges Alternieren von Links- und Rechtslage sowie bei allen Tieren eine Bevorzugung bestimmter Schlafstellen. Einige Beobachtungen weisen auf das Auftreten des paradoxen Schlafs bei den Nashörnern hin.
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.
Predatory and Foraging Behaviour of Brown Hyenas (Parahyaena brunnea (Thunberg, 1820)) at Cape Fur Seal (Arctocephalus pusillus pusillus Schreber, 1776) Colonies.
Diss. Uni Hamburg. 210 Seiten.
The predatory and foraging behaviour of brown hyenas (Parahyaena brunnea) was observed at mainland Cape fur seal (Arctocephalus pusillus pusillus) breeding colonies in the southern Namib Desert. The objectives of this study were to
(1) assess the availability, condition and accessibility of seals for brown hyenas,
(2) evaluate the importance of the coast for brown hyena abundance, movement and energy budget,
(3) determine factors influencing the foraging related time budget of brown hyenas,
(4) assess feeding preferences, and
(5) examine the consumption of prey.
Behavioural observations were conducted at the Van Reenen Bay seal colony and seal pup mortality data was recorded at the Wolf Bay seal colony.
GPS collars were fitted on coastal brown hyenas to determine their movement. Live seal pups were available for brown hyenas all year round, but their increasing size, mobility and activity, as well as the attendance pattern of adult females may influence the brown hyena’s foraging behaviour. Many dead pups were available to scavenge during the pupping season and represented an easy and safe way to obtain food.
In general, predators and prey are mutually influenced by each others behaviours. In Chapter 4 the anti-predator strategies of Cape fur seals towards brown hyenas were reviewed and assessed with regard to their influence on the hyena’s foraging strategies. Although Cape fur seals showed a near complete lack of anti-predator behaviour, the predator-prey system is possibly donor-controlled (Chapter 5) and the usual depensatory effect on prey populations that face novel or exotic predators is not expected (see Sinclair et al. 1998). The numerical response of predators to increased prey numbers as predicted by Holling (1959, 1965) could not be seen in this study (Chapter 5), and seasonality in the availability of seal pups, therefore, may limit brown hyena population growth, and may contribute to the maintenance of large home ranges despite localised food sources. However, coastal brown hyenas’ daily movements were less than that of inland ones, they have a lower field metabolic rate, and hence may consume less food.
Brown hyenas preferred to kill seal pups despite the availability of carrion (Chapter 6). The predation rate was unrelated to carrion availability, but the absolute number of kills was positively correlated to seal pup density. Increasing seal pup density led to an increase in brown hyena capture rate and hunting efficiency. Furthermore the overabundance of easy and vulnerable prey led to surplus kills. However, brown hyenas foraged opportunistically by scavenging, killing and caching seal pups in proportion to their occurrence at the colony (Chapter 7 and 8), and hence, caused an additional impact on seal pup mortality by not only choosing the doomed surplus. The killing of seal pups seemed to be unrelated to hunger, and surplus killing occurred throughout the study period. Brown hyenas preferred to consume larger and heavier prey, but a large proportion of the brown hyena’s prey was only partially consumed (Chapter 8). Selectivity increased with seal pup density, and feeding and handling times per prey item were reduced. Brown hyenas showed a preference for brain tissue, and the consumption of brain tissue may quickly satisfy the brown hyena’s metabolic requirements, or may be important to keep a positive water balance. Although black-backed jackals (Canis mesomelas) outnumber brown hyenas and are their main competitors at seal colonies, they did not influence the brown hyena’s foraging strategy.
Brown hyenas, therefore, behave opportunistically regarding their feeding preferences and optimally regarding the consumption of seals. Seal pup density influences the brown hyena’s predatory and foraging behaviour, and seasonality in seal availability may limit brown hyena abundance and influence their movement patterns. Future observations of foraging brown hyenas outside the pupping season and at night could yield additional interesting information about adaptations in predatory and foraging behaviour to changes in seal behaviour, abundance and attendance.