Sex and age differences in juvenile social priorities in female philopatric, nondespotic blue monkeys

Abstract

Juveniles should choose social partners on the basis of both current and future utility. Where one sex is philopatric, one expects members of that sex to develop greater and sex-typical social integration with group-mates over the juvenile period. Where a partner's position in a dominance hierarchy is not associated with services it can provide, one would not expect juveniles to choose partners based on rank, nor sex differences in rank-based preferences. We tested these ideas on 39 wild juvenile (3.2-7.4 years) blue monkeys (Cercopithecus mitis stuhlmanni), cercopithecines with strict female philopatry and muted hierarchies. We made focal animal observations over 6 months, and computed observed:expected amounts of proximity time, approaches and grooming given to various social partners. Overall, our results agree with the hypothesis that juvenile blue monkeys target social partners strategically. Spatial proximity, approaches and active grooming showed similar patterns regarding juvenile social preferences. Females were far more sociable than males, groomed more partners, reciprocated grooming more frequently, and preferred-while males avoided-infants as partners. Older juveniles (5-7 years) spent more time than younger juveniles (3-4 years) near others, and older females were especially attracted to infants. Close kin, especially mothers and less consistently adult sisters, were attractive to both male and female juveniles, regardless of age. Both sexes also preferred same-sex juveniles as social partners while avoiding opposite-sex peers. Juveniles of both sexes and ages generally neither preferred nor avoided nonmaternal adult females, but all juveniles avoided adult males. Partner's rank had no consistent effect on juveniles' preference, as expected for a species in which dominance plays a weak role. Juveniles' social preferences likely reflect both future and current benefits, including having tolerant adult kin to protect them against predators and conspecifics, same-sex play partners, and, for females, infants on which to practice mothering skills. Am. J. Primatol. 72:193-205, 2010. (c) 2009 Wiley-Liss, Inc.

Sex Differences in the Development of Aggressive Behavior in Rhesus Macaques (Macaca mulatta)

“…In Japanese macaques, juveniles show no sex differences in aggressive behavior, but males become much more aggressive than females in adulthood ). In young primates, therefore, sex differences in aggressive behavior do not necessarily anticipate adult patterns (Cords et al 2010;Raleigh et al 1979;Wolfheim 1977), as juvenile behavior may reflect the immediate needs of this age, which might differ from those of adults (Cords et al 2010).…”

“…Individuals might thus reduce future competition by diminishing the viability of young females (Dittus 1979;Silk and Boyd 1983), so that females might tend to receive more aggression than males by other troop members, e.g., Japanese macaques , toque macaques (Macaca sinica: Dittus 1977Dittus , 1979, and bonnet macaques (Macaca radiata: Silk et al 1981). Although some studies have failed to document sex differences in aggressive behavior, e.g., green monkeys (Cercopithecus aethiops sabaeus: Raleigh et al 1979), blue monkeys (Cercopithecus mitis stuhlmanni: Cords et al 2010;Ekernas and Cords 2007), and Japanese macaques ), other studies found sex differences in aggression, with males being involved in more aggression than females (baboons, Papio species : Owens 1975;Young et al 1982;talapoin monkeys, Myopithecus talapoin: Wolfheim 1977).…”

Kinship and sociability in eastern grey kangaroos

“…It thus seems that daughters and sons behave similarly towards their mothers when young-at-foot, at least during foraging periods. These results concur with those in yellow-bellied marmots Marmota flaviventris (Smith, Chung & Blumstein 2013) but contrast with findings in many primate species in which sex-differential juvenile behaviour occurs (Cords, Sheehan & Ekernas 2010;Pereira & Fairbanks 2002). Eastern grey kangaroos are highly dimorphic as adults ), but sex-differential social behaviour may not occur before weaning or adulthood.…”

Maternal and Alloparental Discipline in Atlantic Spotted Dolphins (Stenalla frontalis) in the Bahamas

“…Only male juveniles were observed disciplining calves in this study, and may account for the low proportion of juveniles that performed discipline relative to adults. The possibility that juveniles, specifically females, were underrepresented in this study is high considering juvenile females have been reported to be more attracted to young and more likely to perform parental care towards young than males in human and non-human primate species, as well as in cetacean species (Cords, Sheehan, & Ekernas, 2010;Herman, Measday, & Wallen, 2003;Maestripieri & Pelka, 2002;Mann & Smuts, 1998;Waitt, Maestripieri, & Gerald, 2007). Nonetheless, discipline is often considered a component of parental care, suggesting reproductively active adults are more likely to be reported performing discipline.…”