mother. See monitor mother. Bonobos show similar behavior. See videos. thrust Plooij THU. Goodalls Pelvic thrust: Rhythmic back and forth movements of the pelvis Occurs during copulation and in reassurance mounting Two adult males embrace ventro-ventrally and bipedally in reassurance or reconciliation, and one thrusts against other. Adult females occasionally mount other females and thrust. Immatures thrust in play. May thrust on part of others body such as leg or on object. Adolescent male, Cadmus, thrust against colobus carcass. Bonobo males thrust bipedal 189 thrust like chimpanzees. See video. thrust bipedal Stand upright on feet and thrust in non-mating context. Courtship or reassurance shown by few adult and adolescent males. Intention movement of copulation likely as origin. See video. thrust in vacuum Thrust, but without any conspecific or