Port, Markus

[["dc.bibliographiccitation.firstpage","487"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","American Journal of Physical Anthropology"],["dc.bibliographiccitation.lastpage","497"],["dc.bibliographiccitation.volume","140"],["dc.contributor.author","Kappeler, Peter"],["dc.contributor.author","Mass, Vanessa"],["dc.contributor.author","Port, Markus"],["dc.date.accessioned","2017-09-07T11:48:21Z"],["dc.date.available","2017-09-07T11:48:21Z"],["dc.date.issued","2009"],["dc.description.abstract","Optimal group size and composition are determined by both the costs and benefits of group living for the group's members. Verreaux's sifakas (Propithecus verreauxi), a diurnal lemur, form multimale multifemale groups with the tendency toward even adult sex ratios despite a small average number of females per group. The unexpected presence of multiple adult males may be explained by tolerance of other group members if subordinate males provide benefits to the group that outweigh the costs associated with their presence. Results based on both demographic data collected over a 13-year period and behavioral observations suggest that subordinate males provide no benefits in terms of infant survival and defense against group takeover by outside males. Although groups with more males are more likely to win intergroup encounters, subordinate males do not participate in these encounters more often than expected. Subordinate males are not costly to other group members in terms of direct intragroup feeding competition, but aggression rates between dominant and immigrated subordinate males increase in the mating season. Even though subordinate males provide very few benefits to the group, they are not very costly either and thus may be tolerated by resident females and dominant males. This tolerance may help to partially explain the tendency towards their unusual adult sex ratio."],["dc.identifier.doi","10.1002/ajpa.21091"],["dc.identifier.gro","3150775"],["dc.identifier.pmid","19425098"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7565"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0002-9483"],["dc.title","Even adult sex ratios in lemurs: Potential costs and benefits of subordinate males in Verreaux's sifaka (Propithecus verreauxi) in the Kirindy Forest CFPF, Madagascar"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","373"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Folia Primatologica"],["dc.bibliographiccitation.lastpage","373"],["dc.bibliographiccitation.volume","79"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2018-03-22T13:14:54Z"],["dc.date.available","2018-03-22T13:14:54Z"],["dc.date.issued","2008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13118"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.title","Grooming for aid or grooming to stay? Patterns of social grooming in free-ranging red-fronted lemurs (Eulemur fulvus rufus)"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","787"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","The American Naturalist"],["dc.bibliographiccitation.lastpage","800"],["dc.bibliographiccitation.volume","178"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Kappeler, Peter"],["dc.contributor.author","Johnstone, Rufus A."],["dc.date.accessioned","2017-09-07T11:49:01Z"],["dc.date.available","2017-09-07T11:49:01Z"],["dc.date.issued","2011"],["dc.description.abstract","The evolution of group living has attracted considerable attention from behavioral ecologists working on a wide range of study species. However, theoretical research in this field has been largely focused on cooperative breeders. We extend this line of work to species that lack alloparental care (hereafter termed “noncooperative species”) but that may benefit from grouping by jointly defending a common territory. We adopt a demographically explicit approach in which the rates of births and deaths as well as the dispersal decisions of individuals in the population determine the turnover rates of territories and the competition for breeding vacancies thus arising. Our results reveal that some of the factors thought to affect the evolution of cooperative breeding also affect the evolution of group living in noncooperative species. Specifically, high fecundity and low mortality of resident individuals both increase the degree of habitat saturation and make joining an established group more profitable for nonresidents (floaters). Moreover, if floaters can forcefully take over territories, the degree of habitat saturation also affects the chance that residents become targets of takeovers. In this situation, communal defense of territories becomes an important benefit that further promotes the evolution of group living."],["dc.identifier.doi","10.1086/662672"],["dc.identifier.gro","3150934"],["dc.identifier.pmid","22089872"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7736"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0003-0147"],["dc.title","Communal Defense of Territories and the Evolution of Sociality"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","620"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Biology Letters"],["dc.bibliographiccitation.lastpage","622"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Johnstone, Rufus A."],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2017-09-07T11:48:30Z"],["dc.date.available","2017-09-07T11:48:30Z"],["dc.date.issued","2010"],["dc.description.abstract","The evolution of group-living has fascinated but also puzzled researchers from the inception of behavioural ecology. We use a simple optimality approach to examine some of the costs and benefits of group-living in redfronted lemurs (Eulemur fulvus rufus). We show that dominant males profit from accepting subordinates within their groups, as the latter significantly decrease the likelihood that the group is taken over by intruders. This benefit is large enough to outweigh the costs of reproductive competition and may constitute the driving force behind the evolution of multi-male associations in this species."],["dc.identifier.doi","10.1098/rsbl.2010.0091"],["dc.identifier.gro","3150835"],["dc.identifier.pmid","20236969"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7628"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1744-9561"],["dc.title","Costs and benefits of multi-male associations in redfronted lemurs (Eulemur fulvus rufus)"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","29"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Animal Behaviour"],["dc.bibliographiccitation.lastpage","36"],["dc.bibliographiccitation.volume","77"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Clough, Dagmar"],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2017-09-07T11:48:23Z"],["dc.date.available","2017-09-07T11:48:23Z"],["dc.date.issued","2008"],["dc.description.abstract","Social grooming is a commonly observed affiliative behaviour in primates. Grooming has been suggested to represent a service in a biological marketplace, exchanged either for grooming or for other social commodities or services. Accordingly, grooming is predicted to be approximately reciprocated within a dyad when no other services are being exchanged, but it should be more asymmetrical if partners have different quantities of other services to offer. We analysed 412 grooming bouts observed in four groups of free-ranging redfronted lemurs to test this prediction. Grooming in this species seems to take place in a highly reciprocal manner because partners usually alternate in the roles of groomer and gromee within a grooming bout. However, within dyads there were asymmetries in the duration of grooming given and received. In both sexes, more grooming was directed from low-ranking towards high-ranking individuals than vice versa, and in males this asymmetry became more pronounced as the number of subordinates per group increased. Grooming in bisexual dyads was generally skewed in favour of males, but patterns of grooming between the sexes were less clear than within the sexes. In addition, aggression occurred at high frequencies between classes of individuals that were characterized by nonreciprocal grooming, suggesting that grooming may serve as a means to reduce aggression in dyads with a high potential for conflicts. Taken together, our results indicate that a strict reciprocation of grooming can be offset by power differentials between partners, where grooming appears to be traded by subordinates in exchange for the tolerance of dominants."],["dc.identifier.doi","10.1016/j.anbehav.2008.08.032"],["dc.identifier.gro","3150787"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7578"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0003-3472"],["dc.title","Market effects offset the reciprocation of grooming in free-ranging redfronted lemurs, Eulemur fulvus rufus"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","46"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Evolutionary Anthropology: Issues, News, and Reviews"],["dc.bibliographiccitation.lastpage","56"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2017-09-07T11:49:02Z"],["dc.date.available","2017-09-07T11:49:02Z"],["dc.date.issued","2010"],["dc.description.abstract","The number of adult males in a group is one of the most variable aspects ofprimate social organization. The causes for this variation have constituted alongstanding focus in primatological research.1As a male’s reproductive suc-cess is mainly limited by access to females,2competition among males shouldresult in the exclusion of rivals from groups of females.4,5However, a great num-ber of primate species live in groups with several adult males. To explain thecauses and consequences of this shared male group membership, primatolo-gists have begun to examine the phenomenon within the framework of repro-ductive skew theory. This body of game theoretical models was developed toexamine variation in reproductive skew within and across populations and spe-cies and to explain the preconditions for stable associations, as well as howreproduction should be distributed therein.6–9 Here we summarize the main aspects of this theory, review its application to studies of male reproductivestrategies, and identify pitfalls associated with using this approach."],["dc.identifier.doi","10.1002/evan.20243"],["dc.identifier.gro","3150937"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7739"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1060-1538"],["dc.title","The utility of reproductive skew models in the study of male primates, a critical evaluation"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1477"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Behavioral Ecology and Sociobiology"],["dc.bibliographiccitation.lastpage","1488"],["dc.bibliographiccitation.volume","62"],["dc.contributor.author","Kappeler, Peter"],["dc.contributor.author","Port, Markus"],["dc.date.accessioned","2017-09-07T11:48:20Z"],["dc.date.available","2017-09-07T11:48:20Z"],["dc.date.issued","2008"],["dc.description.abstract","The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative of these lemurs, the redfronted lemur (Eulemur fulvus rufus). We tested two central predictions of “concession” models of reproductive skew theory, which assume that subordinates may be allowed limited reproduction by dominant group members as an incentive to remain in the group, thereby increasing the group’s overall productivity. Accordingly, relatives are predicted to receive less reproduction than non-relatives, and the overall amount of reproductive concessions given to subordinates is predicted to increase as the number of subordinates increases. In addition, we tested whether the number of females in a group, a variable not previously incorporated in reproductive skew theory, affected reproductive skew among males. Using microsatellite analyses of tissue DNA, we determined paternities of 49 offspring born into our study population in Kirindy forest (western Madagascar) since 1996 to determine patterns of male reproductive skew to test these predictions. Our analyses revealed remarkable reproductive skew, with 71% of all infants being sired by dominant males, but both predictions of reproductive skew models could not be supported. Instead, the number of females best predicted the apportionment of reproduction among the males in this species, suggesting that current reproductive skew models need to incorporate this factor to predict reproductive partitioning among male primates and perhaps other group-living mammals."],["dc.identifier.doi","10.1007/s00265-008-0577-5"],["dc.identifier.gro","3150782"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?goescholar/3493"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7572"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.relation.issn","0340-5443"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Mutual tolerance or reproductive competition? Patterns of reproductive skew among male redfronted lemurs (Eulemur fulvus rufus)"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","889"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Behavioral Ecology"],["dc.bibliographiccitation.lastpage","897"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Port, Markus"],["dc.contributor.author","Johnstone, Rufus A."],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2017-09-07T11:48:28Z"],["dc.date.available","2017-09-07T11:48:28Z"],["dc.date.issued","2012"],["dc.description.abstract","Theoretical advances in the study of social evolution have highlighted the importance of studying group formation in conjunction with population dynamics. To address this need, a number of demographically explicit models have been developed. We parameterize such a model to study the evolution of multimale associations in Verreaux's sifaka (Propithecus verreauxi), a diurnal lemur living in small multimale–multifemale groups. We use long-term demographic data from a population in western Madagascar to estimate the fitness prospects of different male behavioral strategies. Our results indicate that dispersing male sifaka, rather than searching for a breeding territory of their own (floating), do better joining an established group as a subordinate with limited reproductive opportunities, mainly because they may later ascend to the dominant position. By contrast, resident males should not accept potential immigrants because we could not find any measurable benefit of living in a multimale group for them. There is thus a conflict over group membership between resident and floater males, and we suggest that floaters at least occasionally win this conflict because they have more to gain from joining than residents stand to lose by sharing their territory."],["dc.identifier.doi","10.1093/beheco/ars053"],["dc.identifier.gro","3150838"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7632"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","1045-2249"],["dc.subject","ecological constraints; group-living; Propithecus verreauxi; social evolution; social queuing"],["dc.title","The evolution of multimale groups in Verreaux's sifaka, or how to test an evolutionary demographic model"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]