Effects of Estradiol-17β and Progesterone on Mating Behavior in Female Lesser Bushbabies (Galago moholi) in Captivity

Abstract

The effects of ovariectomy, estradiol-17β, and progesterone on female sexuality were investigated in a prosimian primate, the lesser bushbaby (Galago moholi). Each of eight ovariectomized, adult bushbabies was pair-tested with a male partner in the absence of hormone treatment, during estradiol-17β (E2) treatment (3.125 μg/0.1 ml), and during E2+ progesterone (0.125 mg/0.1 ml) treatment. Pretreatment females were sexually nonreceptive and nonattractive toward the males. In contrast, E2treatment elicited vaginal opening, partial or complete epithelial cell cornification, and female receptivity in all females and elicited the complete mating repertoire in seven pairs. Progesterone treatment opposed the facilitatory effects of E2by inhibiting female receptivity and epithelial cell cornification and inducing vaginal closure. Behaviors were quantified following changes in hormone treatment, vaginal physiology, and the presence or absence of intromission. Female attractiveness (male sexual arousal) was initiated during vaginal swelling and was maintained for the duration of vaginal opening, while female receptivity was manifested exclusively during the period of vaginal opening. Female proceptive behavior was mainly associated with the period of receptivity. This study provided evidence of a strict hormonal regulation of both behavioral and nonbehavioral aspects of female sexuality in a prosimian.