Playing it cool Characterizing social play, bout termination, and candidate play signals of juvenile and infant Tibetan macaques (Macaca thibetana)

Play behaviors and signals during playful interactions with juvenile conspecifics are important for both the social and cognitive development of young animals. The social organization of a species can also influence juvenile social play. We examined the relationships among play behaviors, candidate play signals, and play bout termination in Tibetan macaques （Macaca thibetana） during juvenile and infant social play to characterize the species play style. As Tibetan macaques are despotic and live in groups with strict linear dominance hierarchies and infrequent reconciliation, we predicted that play would be at risk of misinterpretation by both the individuals engaged in the play bout and by those watching, possibly leading to injury of the players. Animals living in such societies might need to frequently and clearly signal playful intent to play partners and other group members to avoid aggressive outcomes. We gathered video data on 21 individually-identified juvenile and infant macaques （one month to five years of age） from the Valley of the Wild Monkeys, Mt. Huangshan, China. We used all-occurrence sampling to record play behaviors and candidate play signals based on an ethogram. We predicted that play groups would use multiple candidate play signals in a variety of contexts and in association with the number of audience members in proximity to the players and play bout length. In the 283 playful interactions we scored,juvenile and infant macaques used multiple body and facial candidate play signals. Our data showed that juvenile and infant Tibetan macaques use a versatile repertoire of play behaviors and signals to sustain play

Male Tibetan macaques' (Macaca thibetana) choice of infant bridging partners

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.

Behaviors that predict personality components in adult free-ranging Tibetan macaques Macaca thibetana

To further the potential for applied personality studies, we present a methodology for assessing personality in nonhu man animals without a priori assumptions, using behavioral measures to discriminate personality survey results. Our study group consisted of 12 freeranging, provisioned, adult Tibetan macaques Macaca thibetana at the Valley of the Wild Monkeys, China. We asked familiar Chinese park guards and scientists to rate each of the 12 macaques using 27item personality surveys. We also recorded behavioral observations （〉 100 hrs） from AugustSeptember, 2012. The personality surveys showed reliability in 22 of the items that were then utilized in a principal component analysis that revealed five components： Insecurity, Reactivity, Boldness, Sociability, and Leadership. Prior personality research on Macaca show comparable components. In order to determine which behaviors would best predict those five personality components, we conducted discriminant analyses using behavioral measures as predictors. We found that behavioral measures of avoidance, lunging, feargrinning, selfdirected behaviors, touching, proximity and chasing could significantly predict personality component scores in certain situations. Finally, we analyzed the effects of situation （provisioning and tourists） and found situation influenced proximity and rates of avoidance and selfdirected behaviors. Wider implementation of this methodology may permit longterm analysis of personality using behavioral proxies for established personality traits, in particular on research investigating the effects of tourism and provisioning on personality .