play in juveniles. See video. erect hair See bristle. erect penis Plooij PEN. Goodalls Penile erection. Occurs during sexual and food excitement. See also adduct penis. Kanos Penile erection for bonobos. See video. See also video open thighs. escape Leave area when more dominant individual targets present in party. For example, when estrous female moves to another sex partner, she departs while often looking back or glancing at other adult males to monitor possible attack. 3. E 72 extend hand estrous cycle See swelling of sexual skin. estrus Female copulation confined mostly to period of maximal swelling of sexual skin, which includes day of ovulation. See swelling of sexual skin. See Fig. 14. E Fig. 14 Estrus: Sexual skin with maximal swelling expel Whiten et al. Expel/stir. Nishidas