vacate Upon approach of more dominant individual, one of grooming party leaves partner and vacates position to dominant individual. Subordinate individual also may leave feeding patch when dominant approaches. Cf. supplant. 3. See video. ventral riding See ride ventral. ventro-dorsal copulation See copulate dorso-ventral. ventro-ventral copulation See copulate ventro-ventral. ventro-ventral embrace See embrace full. vertical climb See climb vertical. vertical leap See leap down. vertical slide See slide down vertically. vigilance Visual monitoring to collect information on possible threat of predation or of social conflict among conspecifics. See glance, look, monitor, and watch. visit Migrate temporarily from one unit group to another. Adolescent and young nulliparous adult females in estrus visit neighboring groups, then return to natal group when sexual skin deflates. Known from Gombe, 199 200 vomit