title: Mating behaviors of the proboscis monkey (Nasalis larvatus).
abstract: The mating behaviors of the proboscis monkey were observed in a riverine forest along a tributary of the Kinabatangan River, Sabah, Malaysia, for a period of 30 months. Solicitation for copulation was initiated frequently by males and occasionally by females. Most copulations involved only one mount; however, some multiple-mount copulations were observed and a maximum of six mounts per copulation were recorded. The mean duration of mounts was about 27 sec. Nonsexual mounts (female-female, female-juvenile/infant, juvenile-juvenile, and juvenile-infant) were also observed. Female-female mounts occurred shortly after failed solicitations toward males were observed. Harassment by juveniles and/or infants was observed during copulation; however, these harassments apparently did not interfere with copulation. Sexual swelling was evident in 77.4% of copulating females, with copulating subadult females showing the most distinct swelling.
authors.affiliation: Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan. murai@ees.hokudai.ac.jp
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Murai
mesh_terms: D000818:Animals; D016673:Colobinae / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D005836:Genitalia, Female / Q000033:anatomy & histology; D008296:Malaysia; D008297:Male; D012726:Sexual Behavior, Animal