Videos to BEH 3645
In event A an adult male (Acerola) was standing on the problem-box when a second male (Floyd) approached; at this moment Acerola touched Floyd, turned him on his back and started the mount with thrusting movements. Floyd, apparently, exhibited an erection before and after the mount. The mounting lasted 11 seconds and, after dismounting, Acerola resumed the interaction with the box. Floyd stood on the box without interacting with it for 17 more seconds then walked away.
The second event (B) occurred in a socially tense context. An adult male (Açaí) was interacting with the problem-box along with a male juvenile (Feioso) next to him, when another (unidentified) monkey tried to approach them. Açaí pursued and threatened him, and the newcomer ran away up the tree. When Açai climbed down the tree in the direction of the problem-box, he encountered the juvenile in a branch and turned his back to him. The juvenile then mounted him, with thrusting motions, for 6 seconds (and exhibited an erection after the mount).
The next event (C) occurred when Acerola was standing on the problem-box and a juvenile (Feioso) came running, vocalizing loudly and baring the teeth, with the mouth wide open, approaching the adult male and mounting him, with thrusting and vocalizations, for 6 seconds. The adult male made some vocalizations when the juvenile arrived and, during the mount, he turned his head, making eye-to-eye contact, put his right arm over the head of the juvenile and both made some silent bared teeth displays (The silent bared teeth displays are performed with the jaws closed and the baring of the teeth is produced by the retraction of the mouth-corners. Also performed accompanied with vocalizations during courtship and mounts. Displayed by both sexes: Fragaszy et al., 2004). In this recording of this event it is possible to see that Acerola does not show an erection before the mount, but it is not visible after that.In event D, a juvenile (Frank) was standing on and interacting with the problem-box when an adult male (Caju) came near. At this moment, the adult male mounted the juvenile and did some thrusting movements, while the juvenile vocalized, exhibiting some facial gestures like the 'grin' display.