Male-Male Mounting Behaviour in Free-Ranging Golden Snub-Nosed Monkeys (Rhinopithecus roxellana)

Abstract

An all-male band of golden snub-nosed monkeys (Rhinopithecus roxellana) was observed for 3 months in the Qinling Mountains of China, in order to collect data on the frequencies and contextual significance of male-male mounting behaviour. Mounts occurred in a variety of affiliative, dominance-related and sexual contexts, which differed depending upon the ages of the males involved. Mounting behaviour in this group was mainly initiated by adults. Juveniles mounted each other in affiliative contexts (during play and prior to grooming). Adult males mounted subadult and juvenile partners in a greater variety of sociosexual contexts (dominance/rank-related interactions; reconciliation following agonistic encounters, and sometimes as a prelude to receiving grooming). However, subadults and juveniles were never observed to mount adults. In one dyad, involving an adult male and a subadult partner, mounting was more frequent and prolonged, and included bouts of deep pelvic thrusting. Two mounts resulted in anal intromissions and, in 1 case, the subadult partner exhibited seminal emission. Given that the study took place during the annual mating peak period of R. roxellana, it is possible that this unusual male-male sexual activity was related to the absence of mating opportunities for those adults that were excluded from 1-male units.

The De-Scent of Sexuality: Should We Smell a Rat?

“…We found that the earliest stop codon in exon 13 of TRPC2 to appear in primates was at position 71, along the branch leading to Old World monkeys and apes (blue = stop codon present; green = stop codon absent; gray = unknown). The presence of SSSB was determined from behavioral reports, with an uncertain status (indicated by a question mark) applied to genera without confirmed SSSB in the wild (Bagemihl, 1999 ; Carosi & Visalberghi, 2002 ; Chandler, 1975 ; Fang, Dixson, Qi, & Li, 2018 ; Fox, 2001 ; Grueter & Stoinski, 2016 ; Huang, Zhou, Li, Huang, & Wei, 2015 ; Moynihan, 1970 ; Poiani, 2010 ; Sommer & Vasey, 2006 ). Evidence of SSSB in Colobus is taken from a pers.…”

Examining postmounting grooming in male golden snub‐nosed monkeys to investigate the functions of same‐sex mounts

“…No predetermined sequence to attain an unbiased record of the grooming behaviors of each male without a prelude mount (Su, 2014) (3) Tense, in which one male approached or glared at the other, and in most cases the latter then screamed and presented a mounting solicitation (Fang et al, 2018;Huang et al, 2017;Lv et al, 2007). When there was some extreme aggression with physical contact/injuries among adults and subadults or when they were displaying, juveniles also sometimes crouched and solicited mounting, accompanied by a scream, after which they would be mounted by another individual who was approaching.…”

“…There are several AMUs in the all-male band and bachelors may transfer between different AMUs (Zhang et al, 2008). Same-sex mounting behavior in the all-male band/AMU of R. roxellana has been reported in both captive (Huang et al, 2017) and semi-free-ranging groups (Fang et al, 2018;Lv et al, 2007). Hindquarter presentation and ventrodorsal mounting is the prominent pattern of same-sex behaviors in R. roxellana.…”

“…We previously showed that in captive R. roxellana, the dominance assertion hypothesis was partially supported in that the high-ranking male tended to be the mounter and the lower-ranking male, the mountee (Huang et al, 2017). Data from the wild also support these patterns (Fang et al, 2018). However, mounts among the juvenile age class were harder to explain.…”

<Note>First observation of fellatio by a wild non-estrus adult female chimpanzee on an adult male, and subsequent meat sharing in Mahale

“…In primates, sociosexual behaviors without mating have been observed in both opposite-sex and same-sex partners. Some of these examples include mounting without penile penetration in the olive baboon (Papio anubis) (Owens 1976) and in the Japanese macaque (Macaca fuscata) (Takahata 1982), and anal penetration between males in the Geoffroy's spider monkey (Ateles geoffroyi) (Busia et al 2018) and in the snub-nosed monkey (Rhinopithecus roxellana) (Fang et al 2018).…”