title: Male Tibetan macaques'(Macaca thibetana) choice of infant bridging partners.
abstract: Adult male Tibetan (Macaca thibetana), Barbary (M. sylvanus), and stump-tailed macaques (M. arctoides) engage in bridging, a ritualized infant-handling behavior. Previous researchers found a bias toward the use of male infants for this behavior, but its function is debated. Explanations include three hypotheses: paternal care, mating effort, and agonistic buffering. We studied a group of habituated, provisioned Tibetan macaques to test whether adult males' affiliative relationships with females predicted their use of an infant for bridging. We also examined biases for sex, age, and individual in males' choice of bridging infant. We collected data via all occurrences, focal animal, and scan methods, from August to September 2011 at the Valley of the Wild Monkeys, China. We found that male infants were significantly preferred over females for bridging, but of three male infants in the group, only one was used by all males, while one male infant was used less often than expected. Adult males had females they were significantly more likely to be proximate to and/or to groom, but these corresponded to the mother of the bridging infant for only one male. Our results are most consistent with the agonistic buffering hypothesis: lower-ranked males used the alpha male's preferred bridging infant in an attempt to regulate their interactions with the alpha.
authors.affiliation: Primate Behavior and Ecology Program, Central Washington University, WA 98926, USA. bbauer3@alumni.nd.edu.
authors.forename: Briana
authors.initials: B
authors.lastname: Bauer
authors.affiliation: Primate Behavior and Ecology Program, Central Washington University, WA 98926, USA; Department of Anthropology, Central Washington University, WA 98926, USA.
authors.forename: Lori
authors.initials: L
authors.lastname: K Sheeran
authors.affiliation: Department of Psychology, Central Washington University, WA 98926, USA.
authors.forename: Megan D
authors.initials: MD
authors.lastname: Matheson
authors.affiliation: School of Resources and Environment, Anhui University, Hefei 230026, China; School of Life Sciences, Anhui Normal University, Wuhu 241000, China.
authors.forename: Jin-Hua
authors.initials: JH
authors.lastname: Li
authors.affiliation: Primate Behavior and Ecology Program, Central Washington University, WA 98926, USA; Department of Biological Sciences, Central Washington University, WA 98926, USA.
authors.forename: R
authors.initials: R
authors.lastname: Steven Wagner
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D008251:Macaca / Q000502:physiology*; D008297:Male; D008425:Maternal Behavior; D010332:Paternal Behavior; D012726:Sexual Behavior, Animal
keywords: Affiliated infant; Agonistic buffering; Paternal care