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Age-dependent change of coalitionary strategy in male Barbary macaques - PubMed

  • ️Sun Jan 01 2017

Age-dependent change of coalitionary strategy in male Barbary macaques

Eva-Maria Rathke et al. Primate Biol. 2017.

Abstract

Inter- and intra-specific variation in the propensity to form coalitions has been explained by variation in the availability of suitable partners, distribution of fighting ability, coalition profitability, and costs of coordination. Male coalition formation can be an alternative reproductive strategy to one-on-one competition to maximize male reproductive success. Here we focus on age as a state variable to explain within-group variation in individual propensity to form coalitions against other group members. We specifically test the prediction that males conditionally switch from a solo strategy for achievement of high mating success to a cooperative strategy after reaching post-prime age in male Barbary macaques (Macaca sylvanus). We combined new observations with data collected in 2006 and 2008 on the same individuals from one captive group living in semi-natural conditions at Affenberg Salem, Germany, and found that in all years males between 5 and 13 years formed significantly fewer coalitions than males 14 years and older (post-prime). More importantly, we found those males that aged into the post-prime phase to have switched their reproductive strategy and to form significantly more coalitions in 2014 compared to 2008. These first longitudinal data together with earlier cross-sectional analyses in this and other primate species suggest that group-level measures of coalition propensity may be strongly affected by the age composition of groups and that male coalition formation can be a conditional reproductive strategy.

Copyright: © 2017 Eva-Maria Rathke et al.

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Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Figure 1
Figure 1

Relative David's scores ± standard deviation distributed across age. All values were corrected for each period by mean scaling (divided by the mean of the respective period).

Figure 2
Figure 2

Cross-sectional analysis of coalition formation (absolute frequencies). Asterisks denote significance level at P < 0.05 (∗) and < 0.01 (∗∗) in one-tailed exact Mann–Whitney U tests comparing prime and post-prime coalition formation.

Figure 3
Figure 3

Relative frequency of coalition formation of five individuals changing from prime (2008) to post-prime phase (2014).

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References

    1. Alberts SC. Magnitude and sources of variation in male reproductive performance. In: Mitani CJ, Call J, Kappeler PM, Palombit RA, Silk JB, editors. The Evolution of Primate Societies. Chicago University Press; Chicago, USA: 2012. pp. 412–431.
    1. Alberts SC, Watts HE, Altmann J. Queuing and queue-jumping: long-term patterns of reproductive skew in male savannah baboons, Papio cynocephalus. Anim Behav. 2003;65:821–840.
    1. Alberts SC, Buchan JC, Altmann J. Sexual selection in wild baboons: from mating opportunities to paternity success. Anim Behav. 2006;72:1177–1196.
    1. Altmann J. Observational study of behaviour: sampling methods. Behaviour. 1974;49:227–267. - PubMed
    1. Bercovitch FB. Coalitions, cooperation and reproductive tactics among adult male baboons. Anim Behav. 1988;36:1198–1209.

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