Cunnilingus Apparently Increases Duration of Copulation in the Indian Flying Fox, Pteropus giganteus

Abstract

We observed a total of 57 incidences of copulation in a colony of the Indian flying fox, Pteropus giganteus, over 13 months under natural conditions. The colony consisted of about 420 individuals, roosting in a Ficus religiosa tree. Copulations occurred between 07.00 h and 09.30 h from July to January, with more occurring in October and November. Initially males groomed their penis before approaching a nearby female. Females typically moved away and males followed. When the female stopped moving, the male started licking her vagina (cunnilingus). Typically each bout of cunnilingus lasted for about 50 s. In 57 out of 69 observations, the male mounted the female and copulated. The duration of copulation varied from 10 to 20 sec. After completion of copulation, the male continued cunnilingus for 94 to 188 sec. The duration of pre-copulatory cunnilingus and copulation was positively correlated whereas, the duration of pre- and post-copulatory cunnilingus was negatively correlated. Apart from humans, oral sex as foreplay prior to copulation is uncommon in mammals. Another pteropodid bat, Cynopterus sphinx exhibits fellatio with females licking the penis of males during copulation. It appears that bats, especially pteropodids perform oral sex, either cunnilingus or fellatio, possibly for achieving longer copulation.

Human Sperm Competition: A Comparative Evolutionary Analysis

“…Oral sex is depicted in ancestral cave paintings (Angulo & García, 2005). Oral sex occurs across many species (Nishimura, Utsumi, Okano, & Iritani, 1991;Maruthupandian, & Marimuthu, 2013;Palagi, Telara, & Tarli, 2003;Soini, 1987), and behaviors that occur across species indicate the possibility of convergent adaptations. Next, we review how oral sex performed by men on women (cunnilingus) may be related to sperm competition.…”

“…Cunnilingus may be related to male sexual arousal and, therefore, to other sperm competition tactics. Male Indian flying foxes (Pteropus giganteus) that spend more time performing cunnilingus on a female also spend more time copulating with her (Maruthupandian & Marimuthu, 2013), and Maruthupandian and Marimuthu have interpreted this relationship with respect to sperm competition theory. Males typically perform cunnilingus before they copulate and ejaculate (Halpern & Sherman, 1979), suggesting that cunnilingus may influence sexual arousal and consequent sperm competition tactics (e.g., copulatory thrusting, ejaculate adjustment).…”

Oral Sex, Semen Displacement, and Sexual Arousal: Testing the Ejaculate Adjustment Hypothesis

“…Furthermore, the period during which men lose their penile erection following ejaculation (i.e., post-ejaculatory refractory period) may function to prevent them from displacing their own semen (Gallup and Burch, 2004;Gallup, Burch, and Mitchell, 2006). In some species, oral sex affords males longer copulatory duration, and this relationship has been interpreted with reference to sperm competition theory (Maruthupandian and Marimuthu, 2013). The current research investigates whether these findings extend to humans.…”

Duration of Cunnilingus Predicts Estimated Ejaculate Volume in Humans: a Content Analysis of Pornography

“…Gathering scent cues to fertility status also may explain why males of several mammalian species more frequently perform cunnilingus on high fertility females than on low fertility females, including dogs (Dunbar 1977;Kiddy et al 1978), hamsters (Mesocricetus auratus : Murphy 1973;Johnston 1974), bovine (Nishimura et al 1991;Sankar and Archunan 2004), ring-tailed lemurs (Lemur catta: Palagi et al 2003), and pygmy marmosets (Cebuella pygmaea: Soini 1987). Male Indian flying foxes (Pteropus giganteus) that spend more time performing cunnilingus on a female also spend more time copulating with her (Maruthupandian and Marimuthu 2013), and Maruthupandian and Marimuthu have interpreted this relationship with respect to sperm competition theory. Thus, among mammals, cunnilingus may influence sexual arousal and consequent sperm competition tactics (e.g., mounting behaviors, copulatory thrusting, and ejaculate adjustment).…”

“…Some ancestral cave paintings depict humans engaged in behaviors that resemble cunnilingus, but Angulo and García (2005) caution that these depictions are ambiguous and, therefore, may be interpreted in other ways. Cunnilingus occurs across many species (Soini 1987;Nishimura et al 1991;Palagi et al 2003;Maruthupandian and Marimuthu 2013), and behaviors that occur across species indicate the possibility of convergent adaptations.…”