title: Mother-male bond, but not paternity, influences male-infant affiliation in wild crested macaques.
abstract: In promiscuous primates, interactions between adult males and infants have rarely been investigated. However, recent evidence suggests that male affiliation towards infants has an influence on several aspects of the infants' life. Furthermore, affiliations may be associated with male reproductive strategy. In this study, we examined which social factors influenced male-infant affiliation initiated by either male or infant, in wild crested macaques (Macaca nigra). We combined behavioral data and genetic paternity analysis from 30 infants living in three wild groups in Tangkoko Reserve, Indonesia. Our results indicate that adult males and infants do not interact at random, but rather form preferential associations. The social factors with the highest influence on infant-initiated interactions were male rank and male association with the infant's mother. While infants initiated affiliations with males more often in the absence of their mothers, adult males initiated more affiliations with infants when their mothers were present. Furthermore, males initiated affiliations more often when they were in the same group at the time the infant was conceived, when they held a high dominance rank, or when they had a close relationship with the mother. Interestingly, paternity did not affect male-infant affiliation despite being highly skewed in this species. Overall, our results suggest that adult males potentially associate with an infant to secure future mating with the mother. Infants are more likely to associate with a male to receive better support, suggesting a strategy to increase the chance of infant survival in a primate society with high infant mortality.
  
  
  CONCLUSIONS
  We explore social relationships between males and infants in a promiscuous primate, the wild crested macaque. Our novel approach addresses the nature of affiliations both from males' and infants' perspectives. The results show that males and infants form preferential associations. Male-female affiliation, but not paternity, was a significant predictor of interactions initiated both by males and infants. Males initiated more interactions towards infants when the mother was in proximity, while infants initiated more interactions in her absence. Finally, high-ranking males were more likely to initiate interactions towards infants. We demonstrated that paternity is not a good predictor of male-infant affiliations, even in a species with a high reproductive skew and a relatively high confidence of paternity. Our paper is one of the first to show that infants are active agents in establishing and maintaining preferential relationships with males.
authors.affiliation: Jr. Research Group of Primate Kin Selection, Max-Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany ; Research Group of Behavioural Ecology, Institute of Biology, Faculty of Bioscience, Pharmacy and Psychology, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany ; Jr. Research Group of Primate Sexual Selection, German Primate Center, Kellnerweg 4, 37077 Goettingen, Germany ; Courant Research Centre for the Evolution of Social Behaviour, Georg-August University, Kellnerweg 6, 37077 Goettingen, Germany ; Department of Conservation Science, Bristol Zoological Society, Clifton, BS8 3HA Bristol, UK.
authors.forename: Daphne
authors.initials: D
authors.lastname: Kerhoas
authors.affiliation: Jr. Research Group of Primate Kin Selection, Max-Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany ; Research Group of Behavioural Ecology, Institute of Biology, Faculty of Bioscience, Pharmacy and Psychology, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Kulik
authors.affiliation: Primate Research Centre, Bogor Agricultural University, Jl. Lodaya II/5, 16151 Bogor, Indonesia ; Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, IPB Darmaga, Jl. Raya Darmaga, 16680 Bogor, Indonesia.
authors.forename: Dyah
authors.initials: D
authors.lastname: Perwitasari-Farajallah
authors.affiliation: Faculty of Veterinary Medicine, Bogor Agricultural University, Kampus IPB Darmaga, Jl. Raya Darmaga, 16680 Bogor, Indonesia.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Agil
authors.affiliation: Jr. Research Group of Primate Sexual Selection, German Primate Center, Kellnerweg 4, 37077 Goettingen, Germany ; Courant Research Centre for the Evolution of Social Behaviour, Georg-August University, Kellnerweg 6, 37077 Goettingen, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Engelhardt
authors.affiliation: Jr. Research Group of Primate Kin Selection, Max-Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany ; Research Group of Behavioural Ecology, Institute of Biology, Faculty of Bioscience, Pharmacy and Psychology, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Widdig
keywords: Crested macaques; Infant survival; Male-infant interactions; Paternal care; Paternity uncertainty