Sex Differences in the Development of Social Relationships in Rhesus Macaques (Macaca mulatta)

Forming groups of captive rhesus macaques (Macaca mulatta) is a common management practice. New formations of unfamiliar macaques can be costly, with high levels of trauma, particularly as intense aggression is used to establish a dominance hierarchy. Combining previous subgroups into one new group may be beneficial, as some individuals already have established dominance relationships. We tested this hypothesis by forming a new mixed-sex group of rhesus macaques that combined an established group of females with an established group of males. Prior to the mixed-sex group formation, both the female and male hierarchies had been stable for 3 y; after mixed-sex group formation these hierarchies were maintained by the females and were initially maintained by the males for 3 wks. However, the temporary hospitalization (due to a laceration caused by aggression) of the alpha male destabilized the male hierarchy. Age and weight then predicted male rank. Temporary hospitalizations resulted in rank changes for the males, evidenced by reversals in subordination signals. Thisstudy indicates that using established groups of familiar individuals may maintain female hierarchical stability in a mixed-sex group formation, but further research is needed to understand how to maintain and predict male hierarchical stability to reduce trauma. Improved knowledge of hierarchical stability would be invaluable to managers of large rhesus macaque groups and would help improve the welfare of captive rhesus macaques.

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The development of behavioural sex differences in infant rhesus macaques (Macaca mulatta)

Primates ◽

10.1007/bf02557462 ◽

2000 ◽

Vol 41 (1) ◽

pp. 63-77 ◽

Cited By ~ 31

Author(s):

Gillian R. Brown ◽

Alan F. Dixson

Keyword(s):

Sex Differences ◽

Macaca Mulatta ◽

Rhesus Macaques ◽

Behavioural Sex Differences ◽

Infant Rhesus

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Determination of sex of sacrum in adult Macaca mulatta1

10.1101/428748 ◽

2018 ◽

Author(s):

Yan-Mei Wang ◽

Xiao-Fan Han ◽

Xiao-Jin Zhao

Keyword(s):

Sex Differences ◽

Statistical Analysis ◽

Sex Determination ◽

Macaca Mulatta ◽

Rhesus Macaques ◽

Articular Surface ◽

The Other ◽

Transverse Diameter ◽

Two Indices

[Abstract]BackgroundSacrum being a part of pelvis is an important bone for identification of sex in both living primates and fossil ones.AimAim of this work was to examine the sex differences of sacral parameters in rhesus macaques and to compare with those of the other primates.Materials and MethodsFifty-six adult scara of macaques (17 males and 39 females) have been investigated. Measurement of various parameters was done using sliding vernier calliper; and statistical analysis was done using SPSS 23.0 package.ResultsThe present study showed that the cranial breadth of the sacrum, the sacral length, transverse diameter and sagittal diameter of the cranial articular surface, and two indices of relative sacral breadth were highly significant for sex determination in Macaca mulatta. Comparison of the present data with other studies suggest that sex determination of sacrum can be very different in various types of primates.ConclusionThe results suggest that these measures may be functionally integrated in response to locomotion, obstetric adequacy and cephalopelvic proportions in primates. Sacral index is more reliable and should be applied for sex determination of sacrum in various anatomical and anthropological investigations.

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Sex Differences in Primate Social Relationships During Development

The Oxford Handbook of Evolutionary Psychology and Behavioral Endocrinology ◽

10.1093/oxfordhb/9780190649739.013.3 ◽

2019 ◽

pp. 26-41

Author(s):

Joyce F. Benenson

Keyword(s):

Sex Differences ◽

Social Relationships ◽

Rhesus Macaques ◽

Social Play ◽

Great Apes ◽

Adult Males ◽

Critical Factors ◽

Dominance Relations ◽

The Social ◽

Direct Aggression

The chapter focuses on the social development of immature primates across several species in the Cercopithecidae and Hominidae families, in particular rhesus macaques, the great apes, and humans. The chapter provides an overview of critical factors that characterize the rearing environments of immature females and males, including social structure, residence patterns, and dominance relations. Regardless of rearing environment, consistent sex differences in immatures occur in relationships with mothers, adult males, same-sex peers, and infants. Additionally, sex differences regularly are found in rates of development, quests for dominance, frequency of social play, and rate and intensity of direct aggression across species.

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