Description
Behavioral Expression: In both Bottlenose and Spinner Dolphins, animals of the same sex frequently engage in affectionate and sexual activities with each other that have many of the elements of heterosexual courtship and sexuality. For example, two males or two females often rub their bodies together, mouthing and nuzzling one another, and may caress and stroke each other—simultaneously or alternately—with their fins, flukes, snouts (or “beaks”), and heads. Sometimes this is accompanied by playful rolling, chasing, pushing, and leaping. During this activity—which can last anywhere from several minutes to several hours—males may display erect penises. More overt homosexual activity takes a variety of forms. One animal might stroke or gently probe the other’s genital area with the soft tips of its flukes or flippers. Female Spinner Dolphins sometimes even “ride” on each other’s dorsal fin—one inserts her fin into the other’s vulva or genital slit, then the two swim together in this position. Among Bottlenose females, direct stimulation of the clitoris is a prominent feature of homosexual interactions. Two females often take turns rubbing each other’s clitoris, using either the snout, flippers, or flukes, or else actively masturbate against their partner’s appendages. Females may also clasp one another in a belly-to-belly position (as in heterosexual mating) and thrust against each other.
Homosexual interactions also involve a form of “oral” sex in which one animal rubs and nuzzles the other’s genitals with its snout or beak; because both males and females have a genital slit or opening, penetration is also possible in this fashion for both sexes. One animal might insert the tip of its beak into the other’s genitals or perhaps just use its lower jaw to penetrate and stimulate his or her partner. Sometimes this develops into a sexual activity known as BEAK-GENITAL PROPULSION, in which one partner inserts its beak into the other’s genitals and gently propels the two of them forward, maintaining penetration while they swim together. The lower animal may also turn on its side or rotate belly up during this activity. Male Dolphins sometimes rub their erect penises on one another’s body or genital area. This may lead to copulation, in which one male swims upside down underneath the other, pressing his genitals against the other and even inserting his penis into the genital slit (or less commonly, anus) of the male above him (this same position is used in heterosexual intercourse). The two partners may switch positions, alternating during the same session, or perhaps exchanging “roles” over a longer period. If there is an age difference between male partners, either may penetrate the other, and Bottlenose adolescents have even been observed penetrating much older males. Groups of three or four males may engage in homosexual activity together, or one male may masturbate (by rubbing his penis on rocks or sand) while other males are coupling nearby. Homosexual activity is sometimes accompanied by aggressive behaviors, but these can also occur during heterosexual interactions (males and females have been observed diving forcefully at each other, for example, and violently ramming their foreheads together as a prelude to mating). In Spinner Dolphins, groups of a dozen or more dolphins of both sexes sometimes gather together in near “orgies” of caressing and sexual behavior (both same-sex and opposite-sex); these groups are known as WUZZLES.
“Beak-genital propulsion” between two female Spinner Dolphins
Homosexual copulation in Bottlenose Dolphins: the male in an upside-down position is penetrating the male above him
Male Bottlenose Dolphins often form life-long pair-bonds with each other. Adolescent and younger males typically live in all-male groups in which homosexual activity is common; within these groups, a male begins to develop a strong bond with a particular partner (usually of the same age) with whom he will spend the rest of his life. The two Dolphins become constant companions, often traveling widely; although sexual activity probably declines as they get older, it may continue to be a regular feature of such partnerships. Paired males sometimes take turns guarding or remaining vigilant while their partner rests. They also defend their mates against predators such as sharks and protect them while they are healing from wounds inflicted during predators’ attacks. Sometimes three males form a tightly bonded trio. On the death of his partner, a male may spend a long time searching for a new male companion—usually unsuccessfully, since most other males in the community are already paired and will not break their bonds. If, however, he can find another “widower” whose male partner has died, the two may become a couple.
Male Bottlenose Dolphins also sometimes aggressively pursue and copulate with male Atlantic Spotted Dolphins (Stenella frontalis), both adults and juveniles. After an initial chase, the Bottlenose male typically arches and rubs his body and erect penis against the Spotted male, then mounts (and often penetrates) him from an upright, sideways position. This mounting position is distinct from the upside-down, belly-to-belly approach generally used for within-species sexual encounters. Sometimes a pair of Bottlenose males pursue a Spotted male and both partners mount him at the same time. Though often playful, this high-energy interspecies homosexual activity may also be accompanied by aggressive behaviors such as tail slaps, threatening postures, and squawking vocalizations (also part of heterosexual interactions between these two species and among Bottlenose Dolphins, as noted above). In fact, groups of Spotted Dolphins—sometimes accompanied by Bottlenose males—may band together to chase off Bottlenose males that are engaging in these more aggressive sexual interactions. However, even when this activity is accompanied by overt aggression, Bottlenose and Spotted males that interact sexually with one another may later also band together and cooperate with one another. Male Atlantic Spotted Dolphins also engage in homosexual activity with each other, and adults sometimes even copulate with male calves of their own species. In one such instance, adult-juvenile homosexual activity was preceded by a vocalization known as a GENITAL BUZZ, in which the adult male directed a stream of low-pitched, rapid buzzing clicks toward the genital area of the male calf. This sound, which is also a component of heterosexual courtship in this species, may serve as a form of acoustic “foreplay,” actually stimulating the genitals of the recipient via the strongly pulsed sound waves. Bottlenose and Spinner Dolphins of both sexes have also been observed participating in homosexual activity with other species of dolphins in captivity, such as Pacific Striped Dolphins (Lagenorhynchus obliquidens), Common Dolphins (Delphinus delphis), Bridled Dolphins (Stenella attenuata), and False Killer Whales (Pseudorca crassidens).
Two male Bottlenose Dolphins with erections both attempting to mount a male Atlantic Spotted Dolphin (in the Bahamas) using an upright, sideways mounting position
Frequency: Homosexual interactions are a frequent and regular occurrence in wild Dolphins, particularly among groups of younger Bottlenose males. In mixed-sex groups in captivity, homosexual behavior occurs with equal frequency—and in some cases, more often—than heterosexual activity. Male couples are a ubiquitous feature of many Bottlenose communities; in some cases, more than three- quarters of all males live in same-sex pair-bonds. About 30 percent of interactions between wild Bottlenose and Atlantic Spotted Dolphins include homosexual activities (often accompanied by aggressive behaviors).
Orientation: The lives of male Bottlenose Dolphins are characterized by extensive bisexuality, combined with periods of exclusive homosexuality. As adolescents and young males, they have regular homosexual interactions in all-male groups, sometimes alternating with heterosexual activity. From age 10 onward, most male Dolphins form pair-bonds with another male, and because they do not usually father calves until they are 20–25 years old, this can be an extended period—10–15 years—of principally same-sex interaction. Later, when they begin mating heterosexually, they still retain their primary male pair-bonds, and in some populations male pairs and trios cooperate in herding females or in interacting homosexually with Spotted Dolphins. Because only five or six calves are born to a community each year, however, probably no more than half of the adult males are heterosexually active each mating season (and perhaps far fewer if, as some
